TxTtopZ

So the car has had a cold running issue for a while. If you start it and try to go somewhere in a hurry it stumbles and falls on its face.. The car has even "dieseled" on me a few times (runs horrible, wont accelerate, but wont die). Now the problem is all the time, it feels like its running on 6 cylinders. No power anywhere!

I have tested the injectors -
drivers side was 16.5v
pass. side was 16.4v
"9th" cold start injector was 4.2v

Checked CTS and it was fine with 5v going to it. Couldnt really test the sensor itself because... I was being lazy didnt feel like pulling the alternator.

I also looked at all the fuses under the hood and they are all getting power and intact.

Checked all the vacuum hoses and couldnt find anything leaking.
Ran a TPS voltage check.. getting 5v and with .450 with the throttle closed and voltage increases all the way through with no flat spots until it gets to 5v @ WOT as it should.

I also popped out the MAF and looked at it to see if it was damaged, the heated wires appear intact and there is a good seal on the intake hoses.

Then I checked all the ignition wires and they are all intact, with no visible arcs when looking at them in a dark garage.

This is where the test gets funny... I ran a vacuum test using the vacuum port that feeds the fuel press. reg. and it was only at 12" at 700rpm. That sounds a little low to me but it is the original engine, with 106,000 miles on it.

Then I go out to the garage to get the house phone and it REEKS of gas! Like there is most. def. some fuel coming out some orifice it should not be!

I am going to wait for the car to cool off and then take a look at the regulator.

I also need to check the fuel pressure, which I am going to do tonight or tomorrow.

Whats on your minds?? Can we agree the injectors and TPS are good at this point?

TxTtopZ

BUMP -

So I checked my fuel pressure and its at 36psi.

I unhooked the MAF, and drove it for a while and it starts driving better. Then I plug the MAF back in and it drives good....

Whats crazy is this was after I checked the fuel pressure, and maybe there is a way that the fuel rail got some air in it somehow?

When I go around the corner and im low on fuel the car does stall, like the pick up wasnt attached right.
I call the previous owner, and he says he replaced all the sensors and the fuel pump which, all the sensors do look new. So does all the vacuum lines, well... to put it more accurate, the whole engine looks new...

I am going to go for a ride and put some miles on it... see what happens.

Edit... Went for a ride and the thing runs like a top.

Thanks thirdgen for helping me fix my car... (always nice to know you have help when you need it)...

stealthroc89

Glad you got it fixed, wish my probs would go away, I was going to mention the O2 sensor as a source of the problem, if it comes back, take it out and scrub it with some carb cleaner and a soft wire brush or just get a new 1. Its kinda wierd how it runs the same whether the maf plugged in or not. Start it with the maf unplugged, then plug it back in (still running) and you should notice a difference in how it runs. If nothing it could be a maf issue. Just a couple thing to check if the problem comes back.

TxTtopZ

The MAF was plugged back in and the car runs great...
O2's usually set a specific code, 61... but they can be responsible for indirect codes.
There are def. some issues that need further investigation as there was little explanation...
Im just happy its running well, it now feels like its got some better power than before. Whats going on with your car?

stealthroc89

LOL yeah it would throw a code, duh. I think my problem is my 3" maf housing making the engine run lean, even backfiring at high rpm. I've troubleshooted the crap out of it and its the only thing I've changed, so I'm hoping thats it.