Guys, please check out my dynograph and see what you think. Why isn't it a smooth climb? What could be causing this or by some chance is this normal for a big cammed, stalled auto?

http://www.cardomain.com/member_page...jpg?544918-014

 

Nobody has an opinion? A lot of people told me it wasn't my harmonic dampner and wanted to see the graph, but nobody responds now. Hopefully someone can give me a clue. I've been told it looks like drivetrain to him, maybe a sign the converter is too tight for the setup.

 

stock tune?

looks like your car is leaning out up top but not anything dangerous at all. could be a missfire.

do you have a data log of that dyno run?

 

No, this is tuned. It's at the dyno shop now, he sent me this graph. I've been trying to get the data logs from him. I'll bug him again.

 

hmm...it's got a pretty sketchy a/f for a tuned car

def on the rich side for the 1/2 half of the pull

maybe fuel pump is going out or injectors are maxing out

it'd be nice to see what your WOT fp and injector dc are at

 

Was the converter locked during the run?

 

Doesnt look like an opti problem to me really. Usually those will just go nutty and spike up and down really bad (well alot worse than you have). It doesnt really look like valve float either really because the issue is all through the graph.

I would be checking out the plug wires and making sure they were all connected and using a new set of plugs in case one is cracked or something. Thats the kind of trace you usually get when a plug or wire is screwed up and a cylinder is just working about half the time. What plugs are in it and what are they gapped to?

I dont think its the drivetrain, i've dyno'ed lt1's with everything from a stock stall to my car which has right around a 4000 stall in it. The only time i could see it doing it is if your trans was pretty much smoked but they dont usually tend to pull and let off and pull and let off. Especially with little clues like right at 6250rpm the air fuel ratio leans out and the power falls down like a rock. Kind of like misfires were going on.

If you can get datalogs and I can actually see what the computer is reporting along with a dyno of a run where the log was taken I may be able to find it that way. Its kind of hard to do across the country with very very limited info otherwise.

Sorry for not responding sooner.

 

Maybe your tires were slipping on the dyno?

 

No, the converter was not locked in the run, I don't have any way of keeping it locked.

 

Anyone that has the capability to read the log, I have it and the graph the log was from. The log is a .G2P file.

 

Do you have it in mph? If so maybe compare that to the rpm?

 

Are you on stock injectors?

 

Nope, 32# Accels

 

Well, the shop working on it, maybe on to something. The harness that goes to the coil, ICM, and MAF, and the grounds, he said the power wire in the ICM plug was pretty much completely broke, and the grounds were broke. He said he can get a new pig tail and fix that, but he said after messing with that (not fixed though) the graph was better except for the two missfires it had which are probably related to that. Before I took it to him, sometimes it would missfire bad, and it was something in that wiring, because I would unplug my MSD box and plug it back in and the coil and the ICM the same, then it wouldn't missfire for a while. Now, I did have the ICM and coil spaced out at the time, but he thought the ICM needed a better ground, so he moved it back against the head and we thought that fixed most of it, but apparently not. Does this look like something the ICM could be doing if the wiring to it is not good? Maybe we're on the right track finally.