Help needed guys. Check her out here if you want:https://www.thirdgen.org/rides/index...w&rideid=10314 because I may put it up for the year. Here's the scoop. Had her running top notch and I was out on the backroads beating a little on her and under wot and 8psi of boost and 75pis of fuel pressure she crapped on herself. Meaning it felt and sounded like she was running on 7 cylinders instead of 8. I did a comp test and have the folling Cyl/psi 8-210,6-210,4-200,2-210,7-200,5-210,3-205,200. This seems really high to me. The engine has 43k miles on it. Stock distrib, MSD6al box, blaster 2 coil and Accell 8mm wires and NGK plugs gapped at .035. Any ideas???

 

My first question is why are you running 75PSI on those 30# fuel injectors. Why not lower that pressure and upgrade to 36# or 42# injectors?

Second question, have you done a leak-down test at all?

Third question, are there any SES lights?

Forth question, does the car still run now after sitting for a little while?

 

Thanks for the reply:
1) I'm actually still running the stock 19#'ers in my engine. The new engine has 30# SVO's. My FP is normally 40-45psi and under boost my FMU puts it up to 80#'s.
2) I haven't done a leakdown test yet, waiting to get to the parts store to buy the tool.
3)No SES lights
4)Yes it starts up and runs...idles fine, it's when I put it in gear and say back out of my garage go down the street and pull back it back it, it performs the way it did when it felt like a cylinder went.

 

This is kind of basic, but have you checked the plug wires lately?? Make sure you don't have one glued to a header anywhere.

 

When driving normal though, does it run okay? Does this problem only exist under WOT/harsh driving? Its possible your little 19#'ers don't like being pushed to 75-80psi, except in that case I'd expect it just to not function at all instead of only causing problems at WOT..

EDIT: Just saw your info says its an auto. Is this trans built to withstand the extra power the s/c is providing your engine with? If you aren't 100% sure that its in the motor, I guess it could be the trans slipping. Then again, I'm sure you know how that'd feel anyways.

Do you have a laptop and an ALDL cable, or some other datalogging stuff?

What kind of gas are you running on?

 

The problem actually exists at any throttle. I dare not go WOT now fearing the worst. I do have datalogging but wasn't sure that would do anything for me right now. I use moates free software to log. I have checked the wires and am waiting for a fresh set of Taylors to replace my Acells. I also pulled the NGK to put in AC Delco plugs gapped to .035. I'll be doing a leakdown test tomorrow.

 

My truck was running like that for weeks, I checked the fuel pressure, replaced the fuel filter, checked the distributor, changed the cap and rotor, put it on the scope at work couldn't find it. I was going nuts. Finally I decided to replace the 3 month old bosch platinum plug wires from autozone and thats what it was. Not a scratch on any of them either.

I wont buy any plug wires except AC from now on.

 

It really sounds like a plug wire is toast, but just wait until you get the new ones and we shall find out.

 

To all who responded....3 words. Accell plug wires blow. I roasted #6 plug wire without noticing. I had head shield cloth over it because I knew it was close to the header already well it cooked the wire inside without me even seeing it. The 2 wires I didn't check #6 and #8 and out of the two I didn't check of course one was bad. I installed my new MSD wires and walllaaa. Good as gold back up to snuff. Thanks again everyone.

 

Well thats good news then way better then a new engine.

I dident have too many problems with accel wires, had them for 3 years before they needed replaced.

 

Glad to hear the wires helped, nothing worse than having to pull the motor (I know cause the first one I built this rear had a rod knock within 2 hours. ).