It seems every time I fix one thing, I start having another issue. I hope pretty soon there will be nothing else to go wrong!

I was driving the car normally (not even working the boost much), and I came to a stop sign. I took off from the stop sign, and the car starting popping like crazy as if it was running on 2-3cyl. I can run and drive the car okay if I barely touch my foot on the gas pedal, and keep the car in vacuum the whole time (As soon as I push the pedal down enough to where it would start to build boost, it feels like the car wants to die). It is starting very hard, but the idle (although a little low) is pretty clean. I am pulling good vacuum at idle and while driving, and I have checked for boost leaks. Even if there is no load on the engine, (sitting in neutral) and I give it some gas, I will get loud pops coming from the intake (air filter). I tried unhooking the TPS sensor, and the idle picks up to around 1050~1100 rpms, and the car will run much better on part throttle/low rpms. I don't know exactly what that means. I have a few people stumpted on this one, so I figured I would see if anyone else had an idea. Keep in mind that this happened "all of the sudden."

 

Sounds similar to what I just went through. When I gave it gas, it just wanted to die. Turned out to be my afm. I doubt you still have the afm, but I thought I'd let you know what a similar fix was on my 87. The afm was sticking and giving the wrong voltage to the DME so it would run lean and the car would stumble and pull back timing to protect itself.

 

Danny, I use a MAF sensor, so that probably wouldn't be the issue. Thanks for chiming in though!

 

2 things come to mind:

- Bad TPS or
- Bad MAF

If you have data logging capability log both signals. Actually you can log/test the TPS without logging the data.

Oh, first thing is to make sure the MAF is getting a +12V signal

 

HAHAHA, that's EXACTLY how I feel. I have yet to replace the rear suspension, transmission, and uhhh.... actually I think those are the only things I havent replaced.

As for your problem, what was the last thing you replaced on the car? Had everything apart recently? It sounds like your fuel injector wiring harness could be shot. I had issues with mine last year, we patched part of it, this year my car was running like crap, and died, and despite still "getting fuel" I couldnt keep it running as eventually it deteriorated to the point where 2 injectors shorted and died.

 

Surprisingly enough, I just replaced the leaky fuel rail and one of the injector clips felt like the wires could pull in and out a bit inside the boot. I played around with it and it didn't change anything, so I kind of ruled it out. The car ran great all day (like 6hrs of med-hard driving) after I put the fuel rail and intake mani back on, before it started acting up. . .

John, I am sending you an email right now about something. Thanks for all of your help!

 

Just replaced the fuel rail huh? That's what I did last before mine failed... I'm willing to put MONEY on it now. I'll brb, see if I can find one of the injector clips from my harness and take a photo of it. Ted if it is shot, I'll cut the one that Chris White just built me out of my old engine wiring harness and you can solder it in to replace your shot one.

 

Are you using the clips with the Siemmens injectors? If so, I don't see how you can insert them deep enough into the rail....

 

No clips.

 

Just emailed few things to test. Call in the morning if needed.

 

Will do. Thanks John!

 

Mike, I am going to investigate into that injector harness a bit more. Will it be easily visible if I pull off the rubber shroud?

 

Ted I'm shooting a photo of what to look for first right now. Should be online in a minute or two...

 

Ted, for injector harness a ohm meter is your best friend..

 

Basically, pull the little rubber boot back, that'll be your first indication. It's entirely likely there are other places in the harness that are cracked/falling apart too. Chris explained this in depth to me earlier, about how they wires sit fairly stationary over most of the life of the car and when we move them they crack and fall apart rather than flex like they should. I had him rewire my fuel injector harness on my old engine harness, had OTHER engine problems, parked the car 5 miles from his shop, got my trailer, took the car home and found that nearly EVERY connector in my engine bay looked like that when you pulled boots/sheathing back. Tec3 HERE I COME. Which is why if you need it I offered up the rebuilt stuff from my old harness.

I can post it higher res too if you'd like
The boot in that photo is cut, rather than pulled back as it's easier to photograph.