Not so EZ-EFI Question

[TnBlkC230WZ]

I installed an EZ-EFI system on my Nova about six - eight weeks ago. I had two issues, one with the idle and cold driving and the other with fuel pressure. several weeks ago, I resolved the fuel pressure issue which was a filter problem.

I'm still stuck with the inconsistant idle. I've talked to FAST a couple of times but they only want to blame my car. Vacuum leaks and faulty charging system to name two. The car ran perfectly with the carb and was dyno'd by Dyno Speed Racing to get a bench march of power curve and A/F ratios the week before I started the install. I've had it back to Dyno Speed who says there is an issue with the EZ-EFI and I took it to another shop to confirm there isn't a vacuum leak. I'm hoping someone has a suggestion for my problem listed below?

Engine (nothing fancy): ZZ4 with:
Weiand Air Strike intake
1.6 rockers
Comp Cams 26955 springs and matching retainers
Manley Street flow valves (stock size).
Valve job in April.
No porting and the short block is stock.

6 speed transmission.

The symptoms are inconsistent, but this is the trend.

Warm idle, fan and AC off.

If I set the IAC at 15 as recommended by FAST, the idle will fluctuate. It may start as a 100 -200 RPM swing from my idle of 800 RPM. and eventually fluctuate up and down enough for the engine to die. If I blip the throttle to 1200 RPM, it will start to idle correctly for a while again. At this setting, my vacuum will fluctuate.

If I plug the IAC hole or set the IAC to 5 (its lowest setting), it will idle near perfectly. the Idle will sometimes drop to 500 RPM when I let off the gas but recover and idle fine. At this setting, my vacuum is a steady 16 lbs.

Warm Idle, fan and/or AC on or cold.

Anything that causes the IAC count to increase will make the problem worse. With the IAC set at 15, the RPM fluctuation can be 500+ RPM. It does sound like a massive vacuum leak but I don't have a leak. I have to constantly blip the throttle to keep it idleing. if I have to stop quick and can't hit the gas, it will die.

With the IAC at 5, it idles much better. The fluctuations are a consistant 100 - 200 RPM and occassionally higher. It rarely stalls with the IAC at 5.

Cold and AC on:

IAC at recommended setting, it is a battle to keep it running. With it set at 5, It will stall once or twice until it warms up a little.

The most frustrating part:

Once the engine stalls, you have to turn the key off and wait at least 5 seconds to restart. If you wait 4 seconds and try, You will have to wait 5 more seconds. This can seem like an eternity when stalled at a green light.

Other than Idle, the system seems to be working pretty good. My MPG is down about 20%, but I think it is getting better now that the computer is learning. It does take a couple of weeks of daily driving for the computer to learn the engine

[4mul8ion]

Just a SWAG, but is the idle stepper motor bad? I'm making up numbers here but if the idle motor is looking for say 1 volt to open 20%, 2 volts to open 40% or whatever and yours is actually opening up 30% with 1V and 50% with 2V, that overshoot seems to fit what you are describing. Does FAST have a bench test to measure voltage demand from the ECU versus actual idle motor opening?

[avewhtboy]

It could be alternator, what is your voltage at idle? Older alternators were not made to put out voltage at idle, I had to replace the alternator on my 81 Trans am after I put an amp in for the stereo, the radio would cut off at idle.

good luck

[BonzoHansen]

Just a SWAG...

I had to look that up. Scientific Wild Ass Guess

:geek:

[Mr.VENGEANCE]

https://static1.pt-content.com/images/noimg.gif

[TnBlkC230WZ]

I'll have to research the stepper motor. Is that the same as the IAC?

The Altenator is a Powermaster CS130. I installed it a little over a year ago when I put the AC in. It puts out 14 - 14.2 at idle depending on the load at the fuse panel. The FI probably sees a little less since it is conncted to the battery. It is a custom wiring harness and everything goes to the fuse panel first; except the FI.

[4mul8ion]

I'll have to research the stepper motor. Is that the same as the IAC?

Yes. My understanding is that either there is a bypass port that is opened up or, for the old TBI systems, it opened up the throttle plates. Not sure how FAST does it with their EZ system.

I've had similar idle surge problems with an Eagle Talon and a Triumph motorcycle. Both referred to the IAC as a stepper motor but in googling that term, apparently that's not the norm.

[EFI69Cam]

Does the FAST system have a procedure for setting base idle? You set the IAC to full close then adjust the bypass air to a certain idle speed usually lower than set idle speed.

[GregWeld]

I have EZ EFI on an 8 stack injection (using their ECM and Multiport harness)... and had ZERO idle issues.

My thought would be that you didn't allow the ECM to LEARN the TPS (throttle position sensor) process... There is a "set low throttle -- wait - set WOT throttle" learning curve it goes through...

Then you're Idle RPMS input has to match what you've physically set it for.

After that -- I would ask about your vacuum line's -- NO T's? One line straight to the MAP sensor -- NO TEES...

And is your ECM getting a good CLEAN Tach signal?

Did you mount the ECM AWAY from any ignition box??

[Fuelie Nova]

Not to side track the thread but how did the EZ work with the 8 stack system? I run the XFI on an 8 stack.
Tom

[GregWeld]

Not to side track the thread but how did the EZ work with the 8 stack system? I run the XFI on an 8 stack.
Tom

You can read my posts about it on Lateral-G.net -- beginning with post #103

http://www.lateral-g.net/forums/showthread.php4?p=294275#post294275

[TnBlkC230WZ]

It does have a procedure for setting the base idle which I followed. It recommends setting the idle with the IAC count at 15. Doing this causes the problem to get worse, that's why I set it to 5. With it set at 5, it idles good until the AC and fan comes on, then it has problems as stated above. The more the IAC needs to open, the worse it gets.

The computer isn't recording any EMI issues, but I'm replacing my plug wires and rerouting them in hopes of finding a cure. Everying kees suggesting it is an EMI problem.

[4mul8ion]

What about the idle air / fuel target in the advanced options menu? What is that set at?

[68Formula]

Stock camshaft?

[TnBlkC230WZ]

I used my carb settings as my starting point. It was running pretty good with it.

I set the idle AF at 14.2. My carb was idling at 14 - 14.1. The cruise is at 14.4, the carb was at 14.2 and WOT is at 11.5 or 11.8. The carb was at 11.3.

I'm wondering if richening the idle would help.

The cam is a stock ZZ4 with 208 intake and 221 exhaust duration at .050. It is a ZZ4 with an intake and valve train upgrades. The cam and head ports are stock.

[4mul8ion]

I used my carb settings as my starting point. It was running pretty good with it.

I set the idle AF at 14.2. My carb was idling at 14 - 14.1. The cruise is at 14.4, the carb was at 14.2 and WOT is at 13.5 or 13.8. The carb was at 13.3.

I'm wondering if richening the idle would help.

...

From what I've read on FASTs instruction book for the EZ, it seems like the idle AF target can be adjusted while idling. Since your engine liked the carb's 14 - 14.1 it seems like an easy thing to try. Sure beats trying to trace an EMI problem.

[4mul8ion]

Something I found while I was searching for something else. See http://forums.corvetteforum.com/c3-tech-performance/2383465-f-a-s-t-ez-efi-is-anyone-using-this-yet-11.html about halfway down a posting from bluzman2004.

[TnBlkC230WZ]

That is something to check. He is describing my problem. My mechanical starts at 1500 RPM, but I need to check where the vacuum advance starts. When the AC comes on, it bumps the RPM up about 100 RPM. Maybe setting the idle at 700 RPM instead of 800 will help.

[TnBlkC230WZ]

Well, it's not the timing. My Vacuum kicks in around 1300 RPM. I reset the tune and bumped the idle to 850. It will still fluctuate, but hopefully it won't stall. Except for the idle, it is running really good. I may replace the IAC and see what happens.

[4mul8ion]

Hmmm.

The only information I can find about IAC valve operation is from http://www.megamanual.com/ms2/IAC.htm where coolant temp reading is part of the position calculation. I would assume FAST has a similar operation. Deep stretching here but how's the coolant temperature sensor readings? Could it be grounding out occasionally tricking the ECU into thinking the car is really cold or hot?

[David Pozzi]

There is a lead you can connect to the AC to up idle speed when the AC comes on.
I had erratic idle problems at first. I saw idle fluctuation on the handheld display, indicating interference. It was because I didn't run the ECM power wires all the way to the battery. I picked up power at the radiator support right next to the battery and this was enough to cause trouble. Oddly, the TPS signal didn't fluctuate, which is where the manual says it will show up.

What type of ignition do you have? Are you using the tach adapter?

I did have problems with the new fuel pump not coming on at times, still don't know if it's the relay or pump itself.

I have a pet theory that the old style mechanical voltage regulators are not a good idea on cars with modern electronics. The points probably make the voltage fluctuate a lot.

[TnBlkC230WZ]

There is a lead you can connect to the AC to up idle speed when the AC comes on.
I had erratic idle problems at first. I saw idle fluctuation on the handheld display, indicating interference. It was because I didn't run the ECM power wires all the way to the battery. I picked up power at the radiator support right next to the battery and this was enough to cause trouble. Oddly, the TPS signal didn't fluctuate, which is where the manual says it will show up.

What type of ignition do you have? Are you using the tach adapter?

I did have problems with the new fuel pump not coming on at times, still don't know if it's the relay or pump itself.

I have a pet theory that the old style mechanical voltage regulators are not a good idea on cars with modern electronics. The points probably make the voltage fluctuate a lot.

I have a Pertronix distributor and I'm using the Fast Supplied tach adapter. The fuel pump is just a time issue when then engine dies. You have to turn the key off for 5 seconds for it to come back on.

I do have my power wires going all the way to the battery and I'm running a CS130 altenator, so the mechanical regulator is gone. The counter on my hand held doesn't indicate much interference, but if it is only reading the TPS, it could be somewhere else.

The idle issue is directly related to the load on the engine. Idling warm with nothing on, it idles perfectly. Do something that causes the IAC to open and it starts to act up. The more the IAC opens, the worse it gets. The engine idles ok when it is cold or the AC is on or the fan is on. A cold engine, with AC and ran running has no chance of maintaining the idle. The IAC is the closest part to the distributor, perhaps a shield on it will help.

I've changed the plug wires this week, running them on the outsides of the valve covers and behind the heads. I'm hoping this will help. I've been working from home since, so I haven't driven it much.

The EZ-EFI works perfectly except for the idle. I'm hoping to figure it out soon.

[4mul8ion]

...
The idle issue is directly related to the load on the engine. Idling warm with nothing on, it idles perfectly. Do something that causes the IAC to open and it starts to act up. The more the IAC opens, the worse it gets. The engine idles ok when it is cold or the AC is on or the fan is on. A cold engine, with AC and ran running has no chance of maintaining the idle. The IAC is the closest part to the distributor, perhaps a shield on it will help.
...


Maybe there's something not quite right with the MAP sensor. FAST is using a fueling strategy of "Load Indexed Speed Density" where they're comparing manifold pressure to barometric pressure to compensate for altitude changes. See the attached jpg.

If the barometric measurement is screwed up, the calculated pressure difference between atmospheric and manifold difference would put you in the wrong spot on the look up chart across all throttle positions. The self tuning portion would compensate for some of that to get it to run OK but maybe it can't make up the difference when your engine is idling cold with a high load on it. In your original post, you said your mileage was down 20% from your carb days and it has taken a long time to self tune.

How is FAST measuring barometric pressure with just a 1 bar "GM LS1 style" map sensor? Is there another pressure sensor dedicated for just barometric pressure readings or is the 1 bar MAP able to compare manifold pressure to barometric pressure internally?

[TnBlkC230WZ]

Does anyone know if there are non-conductive carburator studs? I want to electrically isolate the throttle body from the rest of the engine. When I originally hooked up the speed sensor on the transmission, I grounded it to the transmission which drove the speedometer nuts at idle.

I'm wondering if the throttle body is picking up interference from the engine. Most of the parts (injectors, TPS, etc) are plastic. The IAC is metal which could be picking up EMI.

[David Pozzi]

When I had my idle issues TPS looked pretty stable, but looking at the idle speed on the display I could see it idling at 800 but it would flash a 1000 now and then. Mostly I could see the 1 show up now and then. I had a more stable idle by setting the throttle blades more open so the IAC was more closed similar to what you are doing. Now it's back around 15. You might pull the exciter wire on your alternator and see what happens. If you had a bad diode the alt might put out some interference that would confuse the ECM. It sounds like something is causing it to get bad input, either Map, idle speed, or TPS voltage.

I can see how the fast rep would ask you about vacuum leaks, any vac leak or intermittent miss would be seen as a lean condition by the FAST and it would add fuel. You might try a much leaner air fuel target and see if that helps.

I'm just throwing ideas out, maybe something will "stick".
David

[TnBlkC230WZ]

That's all. I think I've ruled everything. Definitely no vacuum leaks, I un hooked the altenator with no change. I isolated the throttle body...no change. I even changed the fan motor. I called FASTc and this time he confessed that they have issues with their supplied tach adapter. They recommeded an MSD box.

Any suggestions on which one. I need somthing reliable for a regulary driven daily driver. I'm looking at the 6A, 6AL-2, 6 Plus or the Accell 300+. I don't really need an RPM limiter, but the RPM but a 2 step rev control could come in handy.

[4mul8ion]

Did they say what kind of troubles their having with their supplied tach adaptor? I just got their Multiport retrofit kit with the tach adaptor and was planning on soldering in a resistor in line to help any spikes that might cause troubles. See http://www.cpgnation.com/forum/installing-fast-ez-efi-dui-system-2852.html

Kevin

[TnBlkC230WZ]

Did they say what kind of troubles their having with their supplied tach adaptor? I just got their Multiport retrofit kit with the tach adaptor and was planning on soldering in a resistor in line to help any spikes that might cause troubles. See http://www.cpgnation.com/forum/installing-fast-ez-efi-dui-system-2852.html

Kevin

That might be worth a try. I have nothing to loose. I probably have one in my garage.

[TnBlkC230WZ]

I talked to fast again and they strongly recommended the ignition box. I decided what the heck and put one in. Still skeptical and not wanting to invest in an expensive box, I bought the MSD Street Fire. It was cheap and it has a pretty high duty cycle on the tach signal.

I put it in and it has definitely made a difference. It cruises much better and seems to have more power throughout the power band. The idle has stabilized to a point that I'm happy. I've started fuel economy run and it looks pretty good so far.

It still has two naging issues.

1. When transitioning from cuise to idle. occassionaly it will die. I've started pushing in the clutch early as I come to a stop. If it dies, I let the clutch back out (without touching the gas) and it will start right back up and idle perfectly. Sometimes I have to do it a couple of times. It is worse when it is cold, but it will do it cold or warm.

2. Sometimes it stumbles badly when the fan kicks on. I've put a new motor in the Taurus fan and it had no effect. I did learn the 20 year old Taurus fans still work as good as new.

[David Pozzi]

Our engine is pretty stock, I put the cruse fuel target at it's leanest setting and it' works.

Make sure your plugs are clean.
David

[TnBlkC230WZ]

Our engine is pretty stock, I put the cruse fuel target at it's leanest setting and it' works.

Make sure your plugs are clean.
David

I'll try to adjust the A/F ratio on cruise and see what happens. I have to make a new interface cable first. The FAST data cable fell on the headers last time out and it melted before I could get it off. I'll make the new one with TXL cable so it will survive another header hit.

[TnBlkC230WZ]

Over time, the engine developed a hesitation at low RPM and the idle started rev'ing up when I first let of the gas instead of dropping immediately back to 800 RPM.

On Monday, it stopped idling completely. It died whenever you let off the gas. I called FAST and they said to bring it in, so I took the ECU and throttle body down to them on Tuesday. The good news is I live less than 30 minutes from Comp Cams and I work even closer. I got to what the tech work on it and couldn't find anything wrong.
They then tested it out on there car and couldn't find anything wrong. This was to be expected since it always works when you first set the tune. The tech said to bring the car to them if it still isn't working.

I got it back and reinstalled the ECU and throttle body yesterday. It ran perfect last night and on the way to work today. On my way home for lunch, it started to stall again at idle. Then on my way back from lunch, the hesitation returned.

I'm going to try and reroute my charging cable and see if that helps. If not, I'll drive the car to them on Monday. I've got to get this thing fixed.

[old66tiger]

Any update on the unit???

[GregWeld]

Mine has performed flawlessly... so much so that I'm going to do this same intake (8 stack) and EZ EFI on my 32 Ford. Mine cold starts instanly... idles perfectly... etc.

[TnBlkC230WZ]

Any update on the unit???

The car currently has a serious issues trying to accelerate that may or may not be related to the FI. I haven't had time to really diagnose it. I may have to pull the FI out to know for sure. I'm hoping to get time this weekend.

[David Pozzi]

How full is the tank?
I don't think the external fuel pump is all that good when the fuel level get's low. Too easy to suck air in.

[TnBlkC230WZ]

After posting last night, I got motivated to find what I thought was an ignition issue. I checked it in a dark garage and it turns out the number 8 plug wire and the coil wire are arcing. I applied a some more dielectric grease to the number 8 plug and I'm changing the coil. I think the canister style coil puts primary connectors too close to the secondary tower when running an ignition box, so I've got an MSD Blaster SS coil to separate the wires.

Hopefully this will fix it.

I'll add that my IRM count now stays mostly at zero, but does go as high as 9. I believe all the EMI issues are resolved. When I started this oddessy, it was in the 70s.

EDIT:

I put the new coil in and reterminated the coil wire but nothing changed. I'm at a loss. Posted for help in the ignition section.

[David Pozzi]

If your ignition is producing enough voltage to arc like that, then you may have a bad plug wire or other problem. With everything right in the secondary ignition system, there shouldn't be that much voltage generated, the plug would "fire" and voltage would be limited to enough volts to initiate spark at the plug, but if you were to pull off a wire at a spark plug, then voltage would go through the roof for that cylinder and you would see high voltage and arcing as a result. I've seen plug wires bad enough you could hear them arcing internally, plus this puts a load on the rotor and cap terminals/
David

[TnBlkC230WZ]

If your ignition is producing enough voltage to arc like that, then you may have a bad plug wire or other problem. With everything right in the secondary ignition system, there shouldn't be that much voltage generated, the plug would "fire" and voltage would be limited to enough volts to initiate spark at the plug, but if you were to pull off a wire at a spark plug, then voltage would go through the roof for that cylinder and you would see high voltage and arcing as a result. I've seen plug wires bad enough you could hear them arcing internally, plus this puts a load on the rotor and cap terminals/
David

Thanks David. The plug wires are new MSD Supper Conductor wires. The number 5 wire was also arcing at one of the wire separators. I tried my old Moroso wires which didn't do much better. I pulled the MSD Ignition Box out and the arcing when away. SO, is this normal for an ignition box or is the box faulty? I'm changing the plugs to make sure I didn't have a grounding issue on the plugs.

On a side note, Now that the arcing is fixed, the engine still runs the same, poorly. I only get an hour or two per week to work on it, so progress is slow.

[TnBlkC230WZ]

If your ignition is producing enough voltage to arc like that, then you may have a bad plug wire or other problem. With everything right in the secondary ignition system, there shouldn't be that much voltage generated, the plug would "fire" and voltage would be limited to enough volts to initiate spark at the plug, but if you were to pull off a wire at a spark plug, then voltage would go through the roof for that cylinder and you would see high voltage and arcing as a result. I've seen plug wires bad enough you could hear them arcing internally, plus this puts a load on the rotor and cap terminals/
David

Thanks David. The plug wires are new MSD Supper Conductor wires. The number 5 wire was also arcing at one of the wire separators. I tried my old Moroso coil wire which didn't do much better. I pulled the MSD Ignition Box out and the arcing when away. SO, is this normal for an ignition box or is the box faulty? I'm changing the plugs to make sure I didn't have a grounding issue on the plugs.

On a side note, Now that the arcing is fixed, the engine still runs the same, poorly. I only get an hour or two per week to work on it, so progress is slow.

[TnBlkC230WZ]

I finally go time to work on it Sunday.

Checked the compression, ohm'd the FI harness to ensure the fittings I installed were good and I pulled the distributor to inspect it. Then I changed the plugs and fixed the issue. The FR5LS plugs, which are fairly new, were not doing the job. Installed MR43LTS plugs and all is good. It has more power off idle now too.

Now I just need to fix the original EZ-EFI idle issue.

[GregWeld]

There are "rumors" that the tach adaptors are a problem.... so before you go crazy... see if you can't find some info about that.

If it was me -- I'd go straight out and get an MSD 6 box - and take your tach signal from the tach output.

Reminds me of the old IBM ad where the guy is showing off all manor of wizbang stuff and some guys says "yeah but will it work with such and such".... and then the sales guys says - "you need an adaptor for that". Makes me chuckle every time I think about that.

[TnBlkC230WZ]

I do have an MSD box. I temporarily took it out of the loop while troubleshooting the ignition issue. It makes a difference, but doesn't fix it . It does help the EMI count. I actually got it down to 0 at one point.

[hectore3]

How about the basics. Check your grounds and make sure they are proper.

[4mul8ion]

With the EMI counts down to near zero, I'm wondering if the idle problems are still pointing to a bad IAC for some reason. Did you get a chance to further isolate the metal IAC from EMI interference or just simply change the IAC out?

[TnBlkC230WZ]

I did get the ignition fixed. It was the spark plugs. I still have idle issues though. I'm going to call them again tomorrow.

[tazzz25906112]

Put one on a 467ci Pontiac stroker and had nothing but headaches until we tuned for over 500ci and the car ran great after that..... self learning they say,,, I say you'd better learn yourself or they'll jack until the cows come home with whats wrong with your car not their product.... The BS attitude from them cost another 3 systems I would have ordered otherwise for my other 2nd gen's.....

[TnBlkC230WZ]

Put one on a 467ci Pontiac stroker and had nothing but headaches until we tuned for over 500ci and the car ran great after that..... self learning they say,,, I say you'd better learn yourself or they'll jack until the cows come home with whats wrong with your car not their product.... The BS attitude from them cost another 3 systems I would have ordered otherwise for my other 2nd gen's.....

Did you just tell it the engine was bigger than it actually is?

It is really wierd. Sometimes it will idle perfectly, other times it stalls when I push the clutch in, and sometimes the RPM will go up when I push the clutch in and slowly settle to a normal idle. Sometimes the throttle response is decent and other times, it hesitates.

Question: When monitoring the AF ratio, it fluctuates a lot when I'm just cruising. It will bounce from 13.5 to 15.5. Is this normal?

[4mul8ion]

...
It is really wierd. Sometimes it will idle perfectly, other times it stalls when I push the clutch in, and sometimes the RPM will go up when I push the clutch in and slowly settle to a normal idle. Sometimes the throttle response is decent and other times, it hesitates.
...

Someone else was having idle problems with their EZ. See http://www.cpgnation.com/forum/ez-efi-bad-iac-4394.html. Does this describe what's happening now?

[tazzz25906112]

Did you just tell it the engine was bigger than it actually is?

It is really wierd. Sometimes it will idle perfectly, other times it stalls when I push the clutch in, and sometimes the RPM will go up when I push the clutch in and slowly settle to a normal idle. Sometimes the throttle response is decent and other times, it hesitates.

Question: When monitoring the AF ratio, it fluctuates a lot when I'm just cruising. It will bounce from 13.5 to 15.5. Is this normal?

In the instruction manual there is a tune for over 500ci,,,, try that cause it sure worked for my setup.... It was all good after the 500ci tune, no more stalling especially at idle when cold coming to a stop sign or set of lights when pushing in the clutch...

[mr_nice_guy]

Are you guys still having problems with this setup? I was thinking that it would be a nice addition to my GTO and down the road when I stroke the motor easy enough to retune...

[atl69camaro]

I finally ended up returning my EZ EFI system after putting around 40 hours into unsuccessful troubleshooting. It was just too inconsistent. Sometimes it would crank and seem to run fine while other times it would not even start. I would then retune and think it was fine, only to have it start running like total crap 30 minutes later, seemingly for no reason. There were a few times that I had to limp home after thinking for sure that I was going to get stranded. I really wanted it to work and probably spoke to their tech support more than 10 times before giving up. I was running it on a 540 ci Chevy so maybe this displacement had something to do with it, although FAST said it should work fine.

[GregWeld]

Sad!

I love mine more and more every time I drive it. Sorry to hear you're not such a happy camper.

[old66tiger]

I wonder if the 540 would have been better with a FAST Multiport EZ system? Greg, that is what yours is, right? I am planning on spending the extra $500 to go with the multiport version of FAST. I have thought about the Holley system and the Powerjection system. My buddy has the Holley system on his car that V8TV built and the FI still does not work like it should. The Powerjection system just looks kind of cheesy.

[GregWeld]

Yes -- mine is the multiport system -- which will run 8 injectors.... and you can run just about anything you want as long as they're high impedance versions....

Since the EZ EFI DOES NOT control your timing -- it's only controlling the fueling, it's super simple system. I only cares that you have a good O2 wideband to read O2 --- and it needs a great tach signal -- and a solid MAP (vacuum) signal.... of course is also has ECT (Engine coolant temp) and IAT (intake air temp) but those are so it knows if its cold start -- and it starts tuning when it hits 140*

I've read many threads where people are having "issues" with EFI -- not just EZ EFI..... and I can tell you that if you don't follow basic good solid mechanical connections and read the instructions - and FOLLOW THEM EXACTLY - and if you don't understand fueling and timing and all these other things -- it won't be the EFI that fails you -- it's the install (provided of course that there is not an equipment failure of some kind - which there can be!). The problem with EFI installs is that you have to be really good and methodical to sort out what part of this whole thing is the mess. It's like a guy that doesn't really understand timing and he can only work on the carb and the carb isn't the issue....

These systems aren't really complicated - they're different but not really - they control fuel -- like we used to do with jets -- we now do that with a keyboard - but if you don't get fueling - you're not going to get EFI ---- and if you don't really fully understand timing and timing curve - and total timing -- and or what a motor needs differently when it's cold (like setting the choke to operate properly etc) you're going to really struggle with this stuff. The EZ EFI system is simple in that if you can set your distributor up right -- as far as curve and initial and total.... now you're only dealing with fueling. You can change the fueling via only 3 simple settings in the EZ EFI -- Idle -- Cruise -- WOT. You don't have to go thru VE tables etc. You don't have to mess with timing tables -- or cold start tables... The thing knows what the temp is - and it will take care of that part. You want to get a little better cruise fueling -- then just set the cruise fuel to 14.5 or whatever you think it should be -- and that's it. Have a problem with surging (lean miss) or something - just change that one setting (the cruise A/F ratio) and that's it.

I'm running a 406 cu in SBC with 8 stack throttle bodies -- no Idle air control (or IAC)... and mine starts up instantly when cold and I can drop it in gear and drive off. No stumble no hesitation no warming up (although I do that just out of courtesy to the motor). The motor was built around EFI -- so the cam is wider LSA -- and I used smaller heads this time around (went Dart Pro 1's 180cc) for bottom end and throttle response... and I think the combo of the cam being custom ground knowing we're doing EFI --- and the good vacuum the motor makes -- and the velocity of the air etc all helps. But it certainly isn't anything "special" or anything I did special except to make sure things were right. The ECU runs straight to the battery -- just like they tell you to do... no junctions - no grounding at the frame or motor - both leads run straight to the battery terminals.... and the vacuum source is straight from the intake to the MAP and another line straight to the vac referenced fuel regulator... no t's! And the tach signal is straight from the digital MSD 6 box... There's no teflon tape affecting the ground of the water or air sensors -- and there's no exhaust leaks in or around the O2 sensor etc.

Speaking of which -- I just fixed a couple of upstream exhaust leaks on another car -- they were small but leaks non the less... And I think they affected the O2 sensors by introducing air and causing the factory ECU to then think it was running lean -- so it added fuel and made the motor run fat as all get out. Welded up the couple holes and everything worked mo' betta'. You just can't "cheat" these systems... and that's my main point in all this typing. Don't try to be "it's good enough" or "it'll be okay" ==== because it won't be. It's got to be installed right from the get go.

[old66tiger]

The common denominator for a higher tech induction solution is to make sure that it is installed as instructed. I have seen even the lowest tech electrical device have problems because of silly things like bad grounds. I am hoping that my cam is not too big for this induction. I don't think it is but you never know. Cam swaps are cheap anyway.

[kryptik]

Definitely gonna have to agree with GregWeld...

Pay attention to EVERY little note/warning in the manual, and follow every instruction down to the letter.

If the ECU is anywhere near the alternator or ignition box, relocate it! FAST recommends AT LEAST 2 feet. Make sure your power is direct off the battery. Make sure there are NO EXHAUST LEAKS.

I'm really looking to install this system myself, that's unfortunate to hear that it is not working for some...the fact that it works wonderfully for others leads me to believe that some are not installing it properly, as GregWeld said.

[old66tiger]

I am wondering as long as you have no exhaust leaks upstream of the O2 sensor, it should not make a difference down stream, right?