Thought I had ignition problems, car hits some kind of rev/ignition limiter when I attempt to run full throttle in boost. Changed ICM, coil, and boots. Still doing it. Today I finally got my wideband in. As soon as I go full throttle my AEM pegs at 10. If the car is getting too much fuel would it cause it do act like a 2-step under boost?

I've got a video, if you watch it listen closely and you can hear it. Thanks

http://youtu.be/41Z-dB1jflM

Engine can bog down from too much fuel.



FU Tuning

Big down or physically hit some kind of limiter that doesn't let the engine go any further?

if too much fuel, yes. Are you sure your wideband is reading correctly? Bosch sensors are known for Stoich drift..

I hope it's reading correctly it's brand new, but there's always the chance that I got a faulty one. I messed around more driving the car and I can give it half half throttle and let it build a few psi of boost and it pulls fine. Then as I gradually give it more throttle it starts to intermittently break up the ignition, then when I give it 100% throttle it just breaks up completely with the fast rev limiter sound.

ya, if its new probley not an issue. what plugs and gap are you using?

10 is the richest the AEM will read. If it stays pegged at 10.0 then you are definitely richer than that. You need to get the car retuned to a leaner AFR.

Also check your spark plug gap. Too much gap and you will be blowing out the spark before it can ignite the Air/Fuel(like blowing out a candle). I usually run .032 to .035 gap in my car.

It's stock injectors with the portfueler, im going to monitor the extra injector controller with my laptop and see if I can pull fuel. The plugs are ltr6ix gapped @.035, I then tried .030. Didn't make a difference. I can still boost at like 1/4-1/2 throttle but if I gradually give it gas it breaks up worse and worse.

I thought boosting with stock sized injectors was a big no no!?

It's stock injectors with PE set to 0 rpm so whenever tps threshold is met you it goes into PE mode, it's has the 4 stock injectors with 4 auxiliary injectors for the extra fuel

Retune it then and pull a bunch of fuel out of it. Aim for 11.0 to 11.5 AFRs. When I was running the GM Reflash on my cav it would randomly go pig rich and the car would backfire and lost all power.

compression ratio and amount of boost?

It's stock 10:1 with only 8 psi, rand fine all winter then it started doing it. I thought an injector was going bad. When I installed the portfueler and changed injectors it kept doing it

what do the plugs look like?

I pulled them out a few days ago to regap and they had maybe 500 miles on them and they looked alright maybe a little excessive carbon but not dripping wet. I emailed Hahn and they suggested that I let the fuel pressure regulator only reference atmosphereic pressure. (Supposed to be boost referenced 1:1). I pulled the line off of it and gave it a run and it felt a little better, it didn't break up as quick.

So I modified a copy of hahns tune and reduced their fuel maps by 40%. The car was still rich-ish. It was getting better 10.5-11.5 afr at 1/2-3/4 throttle. 100% throttle was still 10.0 afr. Ignition was still breaking up past 1/2 throttle. Now I'm thinking bad stock injector(s)? Not sure at this point. Still no CEL

Still going to report my findings in case someone wants to chime in.
Disconnected wastegate actuator arm.
Stock fuel pressure regulator with no vacuum or boost signal.
Steady 63psi fuel pressure at all times idle to wot.
Portfueler extra injector controller disconnected.
So that would leave the system back to stock mode. (Stock injectors, no boost, no extra fuel)
I went out and drove it, at full throttle AFR's go right to 13.0. So that's exactly where it should be.
Car feels pretty sluggish but I attribute that to the large intake manifold and 3" exhaust.
Ignition did not break up.
So at this point my problem has something to do with the portfueler and the stock ecu not playing nice together.
I emailed Hahn if I should change the ecu settings to exactly like the 2003 ecu. 3000rpm delay, and 13.0 afr command I think.
As of right now my rpm delay is set to 0.
I'm hoping they tuned the PF with the stock 03 ecu and that's my problem.

You will kill the engine with 13.0 afrs in boost. 11.5-12.0 is the absolute leanest you can go. Even then it could be sketchy.

There was no boost, I was checking a few things.
1. That the fuel pressure wasn't spiking and staying steady.
2. That the PE mode was working properly.
The wastegate actuator arm was disconnected. I was checking to make sure the stock components of the car were working. And a 13.0 AFR is exactly where the stock computer is set to be when in power enrichment mode.
Now I just have to figure out why it goes so rich no matter what when I have the extra injector controller connected.

Hooked the wastegate actuator are back on and connected the extra injector controller back on. Went out for a drive 10.0 afr at anything more than 1/4 throttle at any rpm. Also the ignition cuts instantly at around 5 psi of boost. I kept my foot down while it was break up and it just kept going popping really fast and the Rpms barely climb. I'm out of ideas at this point. Probably going to look into taking it to a shop to have someone else look at it. Still not sure if the ignition problem is from too much fuel or because of the increased cylinder pressure when it gets into boost.

can you post a picture of your plug on here?

6 heat range is really close to threshold with 10:1, I wanna see the plugs to see if you would warrant a 7 heat range here... only the plug will tell. It could be that you are getting pre-ignition rollin in on tip in.

I'll get a picture of it. I've used the same part number plug all winter and last summer and it ran just fine with the same amount of boost.

ahh, ok most likely not the plugs then, carry on

Alright so just to give this thread closure. Today I pulled all the plugs out sprayed them off with carb cleaner and wiped them somewhat clean. I took my junk yard ignition setup and pulled all the boots off. The contacts from the bottom of the coil had rust on all four points. I sanded the rust off so it was clean metal again. I popped out all the springs from each plug boot, checked the boots for cracks. The springs and boots were good so I reassembled them and put it all back together. I disconnected the battery for like 20 min while I was doing all this. I took the car out for a drive. The ignition was still breaking up at anything over full throttle until I got to fourth gear where for some reason the ignition didn't break up. The car was at full throttle and full boost but wasn't going anywhere. It was extremely bogged down. I figured it was good that the ignition stayed though. So I went back home and adjusted Hahns tune, I reduced the maps by 40%, leaning it out. I took it for another drive and the car pulled very nicely AFR was still 10.3-10.5 so it was still rich but at least it was reading above 10 and also pulling very nicely with no ignition break up. I think after I lean it out a touch more it should be perfect. So I guess my problem all along was a mix of ignition and too much fuel. Glad I got it figured out though. I've been fighting it for about a month.