Not so EZ-EFI Question

[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/insta...stem-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/insta...stem-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.