97 TA sputtered/died

[transam1997]

I have a 97 Trans Am w/64000 Miles on it. I have never had any problems with it until the other day. I drove it to the store and on the way back when I started it, it started reving itself up then when I started driving down the road, I hit the gas it started sputtering and died. I was having problems getting it started and when I did it ran really rough and kept dying. I had it towed back and I replaced the fuel filter and put some dry gas in the tank because I put 3/4 of a tank in it the night before this happened. I can go out and start it and it will run a lil rough but doesn't die, after it heats up and I try to restart it, it will either sputter and die or not start at all. All the gages read fine and I checked the air filter and a few other things but can't figure out what it is. If you have any suggestions I would really appreciate them.

[poormillionaire2]

Almost sounds like the damn opti. You could try plugs and wires, but you may have to replace the optispark.

[FormulaLT1]

Well Opti is a very likely cause but it could also be a bad IAC valve or faulty TPS or faulty MAF. You might want to have the car scanned. I would bet on it being the opti though.

[wrightz28]

Sputtering makes me lean towards fual pump failure. Check the pressure out to confirm.

[FormulaLT1]

Originally Posted by wrightz28

Sputtering makes me lean towards fual pump failure. Check the pressure out to confirm.

That is very true , I didn't think fuel pump. Does the vehicle take few trys before it starts? and have you check fuel pressure both at idle and under load?.

[transam1997]

At first thought it might be the fuel pump because when we took the fuel filter off and turned the key on there wasn't any fuel pumping out of the line and u couldn't hear the pump running. If it was the pump do u think that it would slowly go out or would it just quit all together. Is there any way to test the opti spark or the pump. I don't know alot about cars so I appreciate the info.

[wrightz28]

You need to get a fuel pressure gauge that attatches to the fuel rail at the motor. You can get one as low as $30ish, and is a vlueable investment if you plan on repairing your car alot.

Given your narrative(s) I would persue this before the opti. Ignition problems are "normally" jsut a cut out and die ordeal, not sputtering.

[FormulaLT1]

Originally Posted by wrightz28

You need to get a fuel pressure gauge that attatches to the fuel rail at the motor. You can get one as low as $30ish, and is a vlueable investment if you plan on repairing your car alot.

Given your narrative(s) I would persue this before the opti. Ignition problems are "normally" jsut a cut out and die ordeal, not sputtering.

Not really true with the opti since its a optical sensor failing to fire at the correct time or not firing at that cycle at all, so it usually starts off with a stalling and rough running condition, then sometimes stalling and not firing again for a few hours. I agree with checking the fuel pressure first though.

[wrightz28]

Originally Posted by FormulaLT1

Not really true with the opti

This compadre is why I loosly used:

Originally Posted by wrightz28

"normally"

[transam1997]

Alright I checked the fuel preasure. It was reading 30psi with the key on but when I started the car it jumped up to 36psi, in the book I have, it says that the preasure should drop. Was wandering if that means anything significant or if it doesn't sound that bad.Thanks

[FormulaLT1]

That pressure is low. You should be at around 40PSI with the key on and as you go higher in RPM's the pressure should rise to around 47 PSI. Start the car and pull the vacuum hose from the fuel pressure regulator and keep your thumb on the hose end. Watch the guage and make sure the pressure rises to at very least 43 PSI. If it doesn't you fuel pump is not generating enough pressure to keep up with your injectors fuel demand.

[transam1997]

That last comment I wrote was when the car was starting fine. I tried checking the preasure again when the car wouldn't start and there wasn't any preasure at all. Could there be any a reason for that other than the fuel pump...?

[FormulaLT1]

a short in the wiring or a bad relay.