Guys,

I've got a 1988 GTA , 5.0. Last week I took it in for a tune-up because the car was bogging down just a little upon take off, but wasn't that big of a deal. The shop replaced all of the normal stuff (plugs, plugs wires, fuel filter etc,). When I picked the car up I noticed a slight miss at idle, but otherwise the car ran fine for about 3 days, then it began to miss a little more at idle, then totally just wouldn't run at all. The idle is bad, and when I put it in gear to drive, it will pop and pop like it's receceiving no fuel or fire to the plugs at all. I'm at a loss, and my mechanic is trying to troubleshoot. So far we've replaced to 02 Sensor, which help some, but didn't correct the problem totally. We also replace the air intake gasket, which was broken, but no real change. We also check the fuel pressure, and it's okay too. Now we're thinking that it has to be electrical, and there's a short somewhere. Can anyone hear shed any light on this experience?

Thanks,

Jeff

 

If it wasn't missing prior to the tune up then the first place that I would start is by taking a look at the work that has been done. Check the plugs or plug wires and whatever else was done for the tune up. It could be unrelated and just a coinsidence but this is probably the easiest place to start.

 

Thanks Chris C. At this point everything is suspect...

 

So, I had to tune-up job re-checked by a different mechanic, and he too, found no issues with the tune-up. He suggested that I dig further because it's definitely missing. The fuel pressure and compression was check as well. We're thinking electrical. Can anyone give me some more ideas? Oh, I should mentioned that I recently had the engine bay steam cleaned, but didn't notice any difference other than the miss that was already there after the new tune-up, which progressively got worse over the next few days. I really need to run this to ground, so any help is appreciated.

Jeff

 

This. I'd see if I could narrow it down to just one cylinder that is missing. If so, then he's likely got a suspect plug wire, cap or rotor. I'd make sure no wires are touching anything hot like a manifold.

The steam cleaning could have damaged a sensor such as the TPS that could result in symptoms like the OP described.

 

check that your egr solenoid is holding vacuum. mine wasn't and was missing to the point that driving was awful. it caused everything else to look bad and a changing spree soon happened. i wouldn't have noticed it if i wasn't looking for broken wires during my cap/ rotor change. sure enough it wasn't holding vacuum and kept my egr valve open all the time.

 

I want to add that you should check your injectors with an Ohm meter. Your symptoms also mimic bad injector(s). When they heat up, they tend to short out. One shorted injector will bring down the whole bank (side of the engine) making it shake horrendously. A bad one on each side will shut the whole thing down until it cools down.

 

Here's an update. As it turns out, I had 2 bad injectors. Replacing them both today, so hopefully that solves the problem. Thanks for all of your input.

Jeff

 

Replace them all, it's the same amount of labor. Just costs a little more. The other injectors are all ticking time bombs, they will most assuredly fail. You can buy a whole set of rebuilt Bosch IIIs from someplace like southbay for less than $200.