Gen 7 troubles

[xtrmeta]

I'm setting up my new BBC with an Accel Super Ram. I'm using the Gen 7 computer and harness. I have it programmed with a basic program in the Gen 7 software. It idles and starts fine. At part throttle it's fine. But breaks up at higher RPM. When I go in and put the correct specs in the setup and fuel screens it runs worse.
The motor is a 454 with Edelbrock RPM aluminum heads and full roller cam.
This is a brand new motor. I also have the dual sync distrubutor and installed it on number one, rotated the motor back 25degrees and repointed the rotor at number one. Now the book ends there. But All At Accel told me to also set the timing at 15 manually in the computer and use a timing light to adjust the distrubutor. I have not done this part yet.
What do I need to do to clean up the upper RPM.

[camcojb]

That's a tough system to learn on in my opinion. I will say their "feed in all the engine and cam specs and I'll spit out a tune" never was close for me either. What are you using for A/F? Their wideband is known to be inaccurate, so you might double-check with a handheld one if you can get one.

Jody

[xtrmeta]

I've had the Gen 7 on this car for about a year. I had it hooked to a small block first and never really got it to run perfect. Then the motor went so I swapped in the big block. I tried to use as much of the stuff I could from the small block.
It accually ran pretty good on the small block program when I first started.
Al from Accel gave me a basic program that he said matches my motor. So I installed that and it runs better. Breaks up on the upper end. So I went in and fine tuned the setup screens sent it to the ECM and it started to run worse. So I changed it back.
I'm just running the O2 sensor the came with the harness. IT's not a wide band.
The bad part is this is my first time with fuel injection. So I don't know anything about it. I've learned alittle from playing with the program but I don't know how to tune the fuel and timing screens.
The bad part is theres no shops near me that know how to tune it.
I called Turbo People and spoke with Jobe about tuning it. But he is 3 hours away from me.
So if I can get it to run OK now I'd be happy with that. I will be installing a Procharger on it this winter. So I'd like to wait till that is done to put it on a dyno and get it really tuned.

[nitrorocket]

I found the cinnection from the harness to the crank trigger/distributer was giving me problems, played with it for a while and it ran like a champ to 7K.

[xtrmeta]

I'm using the dual sync distributor. So it is using the crank signal from there.
I believe it to be a programing issue since I don't know how to program all of it.

[Hammered]

I have the Gen7 and before you play with the VE and AF tables you need to sync the timing like the Accel tech advised. If it starts and idles then you made it through the red light/blue light procedure okay. The next step is to force timing and then using a timing light, turn the distributor until you get the exact same reading with the light. Tighten it down and don't play with it again. Unforce the timing and then work your way through the VE and spark tables.

The instructions are woefully lacking in even the most basic detail and are full of errors.

A wideband would be a good investment.

Good luck,

John

[OHCbird]

Ditto what Hammerred said. You cant play with the timing until you get the baseline established.

And another ditto on the wideband- they aren't that expensive anymore when compared to the safety buffer you can create, and the power potential of WB tuning.

[xtrmeta]

I did the timing yesterday. It helped some. But it still breaks up on the higher RPMS.

[Hammered]

I am assuming you've double checked all the setup parameters and your fuel pump pressure has been set with the vacuum plugged. It's probably safe to assume the spark table provided by Al is reasonable for your combo. I believe al heads generally require more total spark advance and there should be a lot of info on what works with the BBC E-heads, I know there is for a Pontiac (36-38 degrees).

Setup a datalog with timing, AF, VE, RPM, MAP and O2 correction as a starter. Do some runs and see where your O2 correction is. Adjust your VE table to get less than 5% correction. Some like to keep the correction on the negative side to prevent lean conditions if something fails.

Have you done any of this?

[camcojb]

One other thing, Accel in their infinite wisdom has two power keys to run the tuning; a sportsmen (I think) and the pro key. Without the pro key there are several tables you cannot adjust.

When I began tuning a friends ProCharged 406 we could not get rid of a misfire issue; also had the standard key that comes with the system. I had a friend with a pro key come in and he adjusted the dwell time (I think, it's been a while) and the miss was gone. We were also using their dual-sync and wideband O2.

Jody

[Jim Nilsen]

I was reading in super chevy about an adjustable distributor slip collar for the distributor gear that is sometimes needed to get the cam timing in line with the crank timing. I posted about this question in the ignition section but probably should have posted it here.

If anyone knows anything about what this part is and has a part number I am listening. I haven't called ACCEL yet but it sounds like this could be something you might want to look into since it would probably make it a symptom at higher rpm like you are talking about. They claim in the article that they do it all of the time but I have only heard about this when I read the article.

Jim Nilsen

[xtrmeta]

I was reading in super chevy about an adjustable distributor slip collar for the distributor gear that is sometimes needed to get the cam timing in line with the crank timing. I posted about this question in the ignition section but probably should have posted it here.

If anyone knows anything about what this part is and has a part number I am listening. I haven't called ACCEL yet but it sounds like this could be something you might want to look into since it would probably make it a symptom at higher rpm like you are talking about. They claim in the article that they do it all of the time but I have only heard about this when I read the article.

Jim Nilsen

I'm using the dual sync distributor. So the cam and crank signal get set by rotating it till they are both off. Then drop in the distibutor. Turn the motor back 25 degrees. Then point the rotor to the number one cylinder. I know all that is correct.

[xtrmeta]

I am assuming you've double checked all the setup parameters and your fuel pump pressure has been set with the vacuum plugged. It's probably safe to assume the spark table provided by Al is reasonable for your combo. I believe al heads generally require more total spark advance and there should be a lot of info on what works with the BBC E-heads, I know there is for a Pontiac (36-38 degrees).

Setup a datalog with timing, AF, VE, RPM, MAP and O2 correction as a starter. Do some runs and see where your O2 correction is. Adjust your VE table to get less than 5% correction. Some like to keep the correction on the negative side to prevent lean conditions if something fails.

Have you done any of this?

I have done the setup. First I installed the map provided by Al at Accel. IT ran pretty good as stated above.
Then I went in and fine tuned the setup specs and the Ve table. IT then ran worse. So I switched it back.
As for my fuel pressure it's 44 pounds. My regulater doesn't use a vaccum on it.
I have not done a datalog. Please keep in mine this is my first fuel injected car. So I really don't know much about adjusting things.

[xtrmeta]

One other thing, Accel in their infinite wisdom has two power keys to run the tuning; a sportsmen (I think) and the pro key. Without the pro key there are several tables you cannot adjust.

When I began tuning a friends ProCharged 406 we could not get rid of a misfire issue; also had the standard key that comes with the system. I had a friend with a pro key come in and he adjusted the dwell time (I think, it's been a while) and the miss was gone. We were also using their dual-sync and wideband O2.

Jody
I have the Pro key. My system came with the Sportsmen key but I upgraded it.

[MrForce]

What size injectors are you running? Are they adequate for the BBC? You need to watch the duty cycle. Have you forced the timing (25 degrees works well) and checked to see if the laptop matches the damper. If you are running an ignition box with rev limiting, check to see if chip is a problem ( it happens) or the rev limiter in the DFI software is set too low. If all the set up parameters in both your fuel curve and the one DFI sent you are the same, then what are the differences? Check VE values where yours ran better than theirs. Does it have more fuel or less?
Typically, when EFI setups have problems that appear as RPM increases, it is usually: a) rotor phasing. b) timing errors, and c) lack of fuel due to tuning or undersized injectors. Good luck

[Hammered]

44 psi sounds good. I think MrForce has some good suggestions. When you say you fine tuned the setup and the VE table, what did you do? I assume you're driving the car under acceleration or at sustained speed and making the adjustments while you're driving? You need to adjust the VE table for steady state conditions (i.e., sustained constant rpms). Using the log file, you can see where the O2 correction is at various steady state conditions and adjust the VE table to remove this correction or yield a less than 5% negative correction. Don't worry about being a newb, I certianly don't pretend to be an expert myself.

[xtrmeta]

I'm running 36 pound injectors. I would think they would be OK. I have forced the timing. But I did it at 15 degrees. Should I go back in and do it at 25? It's not a rev limiter problem. The one in the software is set OK.
When I setup the VE table I just entered in the info on the setup screen. I did not go into the map and change anything. I'm not sure how to do that. When I entered my cam lift and compression and the other things it asks. When I hit the calculate button it started running worse. The specs in the program from al are way off from my setup so I am surprised it runs worse.
I have not driven it and tried to tune anything.
Man I really need to learn how to do this stuff. This is getting frustrating.

[Hammered]

Okay, I think we're onto something here. I am not surprised that the calculated setup is worse than the one supplied by Accel. Their calculation algorithym is way conservative and yields a very rich map.

First, the VE table (F2) is the map. That's where you need to start tuning if you have the timing, fuel pressure, firing order, crank reference angle, etc... properly set.

Start by saving your current VE table by hitting F2 and then going to the file menu once you're in the VE table screen.

To familiarize yourself with tuning, with the engine running and the software up and connected, hit the F2 key. This takes you to the VE map. Idle the engine at 2000 rpm and watch which cells stay highlighted. Your engine will probably bounce between two cells or even three. Look at the O2 correction. For example, -10% means that it's pulling out 10% of the programmed fuel to keep the O2 sensor happy (14.7 A:F ratio). You want this to be closer to -3% or even zero so you want to decrease the numbers in the active cells by about 7%. For example, if the cell in question is 0.340, decrease it to about 0.315 and then look at the O2 correction factor to see how close you got. Make sure to hit F10 after changing the number or it won't take effect. You need to change surrounding cells so you have a gradual change across the map (i.e., no spikes or holes). The 3D graph helps you to visualize this.

To do the full range of cells you obviously need to be driving the car. Hopefully you can see why using the datalog feature is important.

I suggest you get and read Jeff Hartman's "Fuel Injection: Installation, Performance Tuning, Modification." I would also read the Accel instructions, as poor as they are, a couple more times. You can also go online and read the Holley Commander 950 instructions. While a completely different system, the tuning methodology is the same and Holley actually took some effort to write decent instructions.

You should be a lot less frustrated once you've taken the time to study up. I don't think any of the available systems allow you to start without knowledge of the basics.

John

[xtrmeta]

I found out last night the gauge on the fuel rail was wrong. The car was only running at 33 pounds of pressure. So I adjusted it to 40 pounds of pressure. I didn't get a chance to drive it yet. I'm going to try it out tonight to see it that helped anything.
Hammered, Thanks, that helps to understand it better. I understand the basics of how to unstall and the basic programming. But in the VE table and timing I'm not really sure.
So you think it is all fuel related and not timing?
I'll take it out for a ride tonight and see what the VE table says.
Thanks

[Hammered]

Most injectors are rated at 43.5 psi so setting it at 44 would be good, but 33 versus 40 is a big difference.

As long as your timing curve is close, which I assume it is if provided by Accell for a like application, then you need to work on the VE table.

[xtrmeta]

Heres an update. When I drive the car when I'm speeding up it keeps popping throught the exhaust. Does it all the time while driving around. Keeps doing it every time I step on the gas to speed up. Crusing at about 3000RPMs is has a slight misfire. The motor is not running smooth.
What would cause these things? Timing or fuel?

[Hammered]

Check your firing order, both wires and in the setup program. Also check your plug gaps. Does your timing table look okay? How did your O2 correction factor look? It sounds more like a timing issue.

[xtrmeta]

The firing order is correct. Both in the wiring and the setup screen. I'm not really sure what the timing table is suspost to look like.
When the car is idling and sitting still it runs great. I can rev it up and it runs smooth all the way through the RPMs.
It only gives a problem under a load.
I also found a blown gasket in the rear of my exhaust. I don't think that had anything to do with the troubles though. It used to blow on the SNC and never caused a problem.
So I'm going to replace that gasket tonight and try it. Just to see.

[DC454]

What do your plugs look like? Do they look fat or lean? Gen 7 DFI or any other stand alone system are never "plug and play". If you have your distributor in sync and the car idles, dyno tuning is your next step. If your new to the system, you might want to pay someone to tune the car. You can blow up the motor trying to street tune your set up.

[xtrmeta]

I plan on taking it to Turbo People for Dyno tuning. I was trying to get it better so I could drive it allittle before it comes off the road.
I'm installing a Procharger on it this winter and didn't want to take it for tuning before it was done.

[DC454]

You need to check if the timing on the computer matches the distributor. In order to do this, pull up the sreen that has the dash board, off on the right of the screen it say's ignition timing. On the bottom of that off to the right it says forced timing. Click that box and it will ask you desired value. Put in 20* and hit set. Now check the timing with a timing light to see if it's at 20*. If it doesn't you'll need to play with the distributor. All of the info is listed in your instruction book.

[Hammered]

DC454: He already synced the distributor in. He's running a program for a like engine provided by Accel tech so he's probably not running as rich as he would be if he was using the initial setup profiles.

xtremeta: The timing table is pretty simple. I'm guessing you should have something like 22-26 degrees at idle (10 initial plus 12 vacuum advance for a similar carbed engine) and 34 or greater at the max rpm, low vacuum (101 kpa - higher numbers mean lower vacuum). Mid rpms and high vacuum should have even higher timing numbers. I'm not a Chevy guy so I don't know what the e-heads would like on your engine. They typically like 36-38 at WOT and peak HP on a Pontiac.

Check your plugs like DC454 recommended. Fouled plugs can cause the symptoms you're experiencing. You might just go ahead and replace them.

I'm guessing you haven't done a datalog yet. At least take a look at your timing and O2 correction factor when you're at a steady rpm and it's popping.

[DC454]

If you have your target air/fuel table set up and the system is in closed loop, you can use the auto calibrate feature in your VE screen.

[68 SuperRam]

I was having the same pop on my car - withe Superram - I changed the plugs - and it solved the problem for alittle while - car runs really rich - itis running really rich - due to problem that I was having with my tranny at the time that Jobe at Turbo People programmed it. Put in fresh plugs before Jobe tunes it for you. He is really cool - he is one of Accel's top R&D guys - I remember him working on and testing the Gen VII system - when I first brought my car to him to program my Gen VI. Good luck.

[jimhamptons]

I plan on taking it to Turbo People for Dyno tuning. I was trying to get it better so I could drive it allittle before it comes off the road.
I'm installing a Procharger on it this winter and didn't want to take it for tuning before it was done.

This is what I am going to do. Jobe is supposed to be one of the best. Let the expert do it and you will be happy in the long run.

[xtrmeta]

I plan on letting him do it. I just didn't want to have to pay for tuning twice since I'll be tearing it down in a few weeks.
As for the plugs there new. The complete motor is brand new. Only has about 20 miles on it so far.
I'm building a new exhaust on it now so it will not have any more leaks. I figured I needed to start there first. Then I'll try some of the tips from you guys to see if they help. If not I'll just start the Procharger install now and get it done and tuned.

[OHCbird]

Have you tried looking at the O2 correction? You've been asked a few times, but haven't posted it.

[xtrmeta]

No I havn't gotten that far yet. I'm working on the exhaust now then I'll take it out and try it to see what it says.
I really appreciate all the help you guys are giving.
I did try to do a data log on it the last time I drove it but I was alone and it was very hard to do.
Is the data log only supost to record for 27 second clips?? Or shpuld it be longer?

[DC454]

Data log can record what ever you set it to. You really need someone else to drive while you work the computer.

[Hammered]

The idea of the data log is so that you can tune the car by yourself. You can set it up to run an hour if you want. You should only need to hit the start key, if that, while you're driving.

[John McIntire]

I too have heard of Job at turbo people, and how good he is. I have also heard that he locks out the ECU so you cant get back into it to change or alter anything, this way you're kind of forced to go back and see him. He does this on 6/7 second cars, might not do it for your street car.

[RSX302]

Heres an update. When I drive the car when I'm speeding up it keeps popping throught the exhaust. Does it all the time while driving around. Keeps doing it every time I step on the gas to speed up. Crusing at about 3000RPMs is has a slight misfire. The motor is not running smooth.
What would cause these things? Timing or fuel?

If you would like, email me your tune and I can take a peek at it. I've gotten pretty good at set-up & tuning Gen 7's.

[email protected]

[xtrmeta]

ronracer,
is that offer still open to take a look at my program. I've been busy and have not had time to get it to you.
I just built a new exhaust on the car so now I need to get it running right.
Thanks

[RSX302]

ronracer,
is that offer still open to take a look at my program. I've been busy and have not had time to get it to you.
I just built a new exhaust on the car so now I need to get it running right.
Thanks

Absolutely...
I just finished tuning a 69 Camaro 540ci with great success. Yea...I was in the car for that so I can't promise you the world, but I can see if I see any major issues.

When you e-mail me, give me your list of components; injector size, engine off fuel pressure, cam profile, compression ratio etc. along with what your having problems with.