87 trans am, stock 305 tpi.

I replaced my intake gasket yesterday and now the engine fires up and then dies almost immediatly. One time the idle picked up to about 1k and it kept running, but when i shifted into gear and the rpms dropped, it struggled and stalled. Thinking it had to do with a stuck EGR valve, I took it out and replaced it with a blocker plate just for now until napa can get me the right egr from california. This did not fix the problem at all. I have the vaccum port coming off the throttle body plugged (for the egr and charcoal canister). everything is plugged in, I triple checked. The distributer is positioned correct, i marked it before i took it out and then double checked after this problem occured.

This problem has ruined 2 days of my vacation and is about to take my last day off tomorrow, not to mention I wont have a way to get to work on thursday if this isnt fixed. Any help or suggestions would be greatly appreciated. I will continue to check this post to answer any questions you may have and to let you know of any updates or if anything works.

Thanks in advance and sorry about all the reading.

 

What did you set the timing to? Did you set it properly?

 

i cant get the car to run long enough to set the timing. I know the distributer is in right, and ive tried advancing it and retarding it to each extreme.

 

Have you checked to make sure all your vacuum fittings have their hoses/plugs on them?

 

yes, all vacuum lines are where they are supposed to be, or they are plugged. Just to make sure... since I got rid of the EGR valve and blocked off the port for it in the intake, its ok if there is no vacuum line going to the EGR solinoid, right?

As an update, when the engine runs for a few seconds the exhaust smells very very rich. I tried throwing a couple parts at it today... replaced the MAF sensor and the IAC motor. These didnt change anything.

Thanks for the help so far, I appreciate it. Keep it coming!

 

i had a similar problem bout a week ago, i was 1 wire off on the cap ,so it was extremely retarded,fixed that and it fired right up and ran perfect.dont know if this your problem or not ,just tryin to help

 

I appreciate the help, yes I'm sure the distributer is in right. I also tried it one notch advanced and one notch retarded from where it is right now.

 

What do you mean by "one notch"??

Did you set your timing with a timing light, or just line up two marks with your fingers crossed?

 

I cant get it to run long enough to get a light on it, but this is what I did...
I took the cap off and rotated the crank till the timing notch lined up with zero, and made sure the rotor was pointed at the #1 cylinder contact on the cap. tried starting it like that, and also tried starting it with the distributer rotated one notch clockwise and one counter-clockwise.

 

ok, today I'm going to check fuel pressure since I finally got a guage. Then I will replace the egr valve and all the plastic vaccum lines coming off the upper plenum. Then... I'm not sure.

I heard somewhere that if you start the car with the A and B ALDL terminals jumped that it starts in diagnostic mode. Is this true? If so what is diagnostic mode exactly? Does it not rely on feedback from certain sensors and just runs according to preset conditions in the PCM?

 

Well i know from experiance that TPI has a MAF sensor. i also know if you get a vacuum leak after that sensor the car will go nuts and either not run or run like garbage. you need to check that possibility very carefully. if the car ran fine until you replaced the intake gasket then logic would state it has something to do with everything you touched when replacing it. also connecting terminals A&B on the ALDL connector does nothing but tell the computer you want to extract codes from it by flashing the SES light. if you want to do that. Turn the key to the on position but do not start it. connect terminals a&b and the SES light will flash once pause then flash 2 times. that code 12 indicating your in diagnostic mode. it will do this 3 times then flash any stored code in numerical order. I hope this info helps. Good thing i pay attention in my classes at UTI...lol

 

Is the car running yet? I still think you are having an ignition problem. Check your firing order. Recheck your timing. You said-

but this is what I did...
I took the cap off and rotated the crank till the timing notch lined up with zero, and made sure the rotor was pointed at the #1 cylinder contact on the cap.
Did you do this before you first pulled the distributor? Did you ever rotate the engine with the distributor out? What I would do after you check that all vacuum lines and wires are hooked up is...
Pull the number one spark plug, pull the cap off dist, put your finger over #1spark plug hole and rotate engine until you feel air pushing up on your finger. Now you are approaching top dead center on the firing stroke for number one cylinder. Line up your timing marks now. Next check to see if your rotor is pointing at number one plug wire. If it is not pull dist, point it #1 bolt down but leave it loose enough you can move it. Now try starting your car. Rotate dist til it fires.

 

Sounds stupid, but did you get the lower runner gaskets on the right side? If not you will have a big vacuum leak. If it ran fine before the intake gaskets were changed chances are it's something related and not a sensor issue.

 

Ok guys I got it running finally. And thankyou for all the help. Here's what happened...

I assumed that the problem had to have something to do with the intake manifold/ vaccum lines I removed etc etc. And I learned my lesson never to assume.... Instead of first checking for fuel and spark, I skipped the fuel check. Well I checked it today and I was only getting about 20psi. I crossed my fingers and changed the fuel filter. (After getting the filter off I could tell it was plugged because it was alot harder to blow air through the old filter than the new one.) The car fired right up. A few things I dont understand though...

1) It's running, but I was still only getting about 20psi in the fuel rail before the car started (I primed it 2 or 3 times and it stayed at 20psi), once it was running the pressure gradually built up 40psi. Is the fuel pump bad?

2) Before I changed the intake gasket I was having a surging problem under loads at about 1200rpm. After realising the fuel filter was plugged I hoped it would solve the problem, but it still surges just like before. Could this also be evidence of a bad fuel pump?

3) Why would changing the intake gasket have en effect on the fuel filter plugging up, or is it just plain coincidence that it decided to plug up enough just then to not let the car run?

 

i wonder if your pressure regulator is about to bite it...

 

If the pressure regulator was bad, wouldnt all the pressure in the line bleed back into the tank and I'd see the guage gradually drop back to zero? Is there a way to test the pressure regulator?

 

i am not sure about this... but i think in theory it should work... the fuel pressure is a constant set by the regulator so if you took the return off the regulator and let the system prime it shouldnt allow gas out of the return port... but i am not sure so see if anyone else has a better idea before possibly spraying fuel all over your engine....

 

a problem may be that on your throttle body, there is a screw that you can screw in and out. screw it in some and up the idle so that it will stay running. let it warm up and adjust it properly. this is a problem sometimes with bad gaskets that get replaced.

 

i dont understand how that would help... maybe some explenation? scott

 

I believe he is referring to the minimum idle speed screw, which I adjusted today along with the timing, and the TPS. And no this wouldnt effect the surging problem that I am having now.

 

The slow pressure buildup is almost a sure sign of a fuel pump on its way out - usually because its been overworked/overheated. A badly plugged fuel filter can do this, so can running the fuel tank too low (fuel is coolant for the pump... too low, it overheats).

Yes, possibly. Not enough fuel pressure can cause some really strange problems that vary from vehicle to vehicle, and a lean surge isn't an uncommon symptom of this.

You probably had a bad fuel pump/clogged filter before your intake gaskets went bad, and the bad intake gaskets just compounded the problem and made it worse, since both problems (low fuel pressure, leaking intake gaskets) can have the same symptoms.

 

Well i checked the FPR today by pinching off the return line and priming the pump and then starting the car. The pressure was the same as before I pinched off the lines (primed up to 20 psi and then ran at about 38psi) When I tipped in the throttle it dropped down to about 25 psi. So it appears that the FPR is ok and the pump is the problem. Everyone agree?

What should I watch out for when dropping the tank? Are there any tricks? I can use my lift at work, but I have to do it after hours (after 9pm). How long do you think it would take using a lift and a tank jack? Also, how much give is in the lines coming straight off the tank? Are they plastic like on newer cars?

 

Run down the fuel level as much as you can before you drop the tank (or drain it) if you KNOW you are replacing the pump. Before you drop the tank, disconnect as many wires and fuel lines as you can... less work later. Aside from that, good luck!

Oh, make sure you replace the fuel filter at the same time, as no manufacturer will give you warranty on a new pump if you don't install a new filter at the same time.