T/A died...SES light on please help w/in

[Craig 94 TA GT]

I was driving the TA today with Steve 93Z. I hadn't got on the throttle in a while (months) so I decided to punch it. Ahhhhhh, the acceleration. But a few minutes after, at a stop light, the idle started to fluctuate. I just thought it was a sticking throttle so when I light turned green, I drove it normally to the next stop light. The car then died. I tried to restart it, but it would not catch. The battery/alternator/starter motor is not the problem because it would turn over fine. Luckly, I had Steve with me, so he was able to push it off to the side. I kept trying to start it and noticed the tach would fluctuate to 3000 RPM, then to 4000 RPM, then back down to 2000 very quickly. Of course, the motor would not catch still. After another few minutes, we tried again and it started. It did miss a few times now and when I hit the brakes hard, the motor wants to die. A few minutes after, again, the SES light came on and I noticed the fans are constantly. Could this be related to the opti, coil, another iginition component, or the fuel pump/regulator/injectors? I just had my plugs/wires replaced 15k ago and they still are fine. My fuel pressure, which I checked recently, was at 43 PSI off, 38 idle. Thanks for any help.

[00 Ragtop Z]

don't discount teh alternator until you are sure. Even witha bad alternator a car will crank, and may even run for a short period. Other than that, coil is a possibility. Did you check teh SES code to see what it said? Probably you next step

[Jeff_in_Atl]

You need to have it scanned. It could be a lot of things but if I was a betting man, I'd bet on the OPTI. That would be a code 16 or 36.

When something goes wrong and makes the SES light go on, the car goes into self protect mode and turns on the fan. That's normal.

[Craig 94 TA GT]

Thanks guys. Considering I don't have a scanner, maybe I'll just take it in to the dealer. Is it possible to be the fuel pump? Would it throw the SES light on, and make it miss/want to die?

[M3EATER - GG '00 WS6 T/A]

Craig,

Most auto parts stores will do a scan for you.

Yes, the fuel pump could creat your symptoms,,, except the light.

Yes, a weak alternator could also do it. When you accellerate hard the ignition must be in proper shape to fire the mixture... a weak alternator could possibly not be putting out the voltage. However, it's likely you'd have problems with a low battery & low crank speed if the alternator were "low" enough to creat this problem.

I'd think that it may be ignition related, as noted above. Again, due to needing more ignition energy to fire it when you accellerate than when just part throttle cruising.

Anyway..... get it scanned.

Good luck & let us know what you find.

Gordon
PPC
www.provenperformanceconcepts.com

[Craig 94 TA GT]

Thanks for the input Gordon.
You know what's funny...I drove the T/A again a few hours after and it ran fine. I was trying to drive it to attempt to diagnose the problem but guess what...no SES light, and it ran perfectly. About an hour later, again, it ran fine. It missed maybe once just around 1000 RPM, but everything was smooth. I got past 3k revs, and there was no trouble. So I don't know what to do if the SES light doesn't turn on anymore...I couldn't get a proper diagnosis.
The only thing I'm still wondering was when it originally died, and I tried to restart it many times, why would the tach shoot up to 4k quickly (many times) if the motor didn't catch? Now that's never happened to me before.

[Joe 1320]

To me it sounds like an intermittant short in the ignition harness. I would go over the harness with a fine toothed comb, especially on the driver's side of the engine's harness tracing from the MAF backward. That is the harness that also contains the coil and driver circuits and I have seen problems that produce the symptoms you describe. I would still have it scanned as the code is stored in memory. If the problem is intermittant, the SES light may go off, but the computer stores the code until a certain number of nonproblem cycles. The code will narrow down your search.

[N20LT4Bird]

Just a shot in the dark, but from the sounds of it you may have a bad ECT. The stuff the other guys mentioned is good possibilities - check it all out, but the fact that the car runs and the fans are on constantly gives me a hunch that it may be the ECT. If the engine is not getting proper coolant temp, especially on a speed density car- it will run very rough. Just a guess (without looking at the scanner). Take it and get it scanned, post the code and we can help you more - DONT TAKE IT TO THE DEALER PLLLLLEAAAASEEE! You will get hosed.

[Kevin - Blown 95 TA]

Originally posted by N20LT4Bird
Just a shot in the dark, but from the sounds of it you may have a bad ECT. The stuff the other guys mentioned is good possibilities - check it all out, but the fact that the car runs and the fans are on constantly gives me a hunch that it may be the ECT. If the engine is not getting proper coolant temp, especially on a speed density car- it will run very rough. Just a guess (without looking at the scanner). Take it and get it scanned, post the code and we can help you more - DONT TAKE IT TO THE DEALER PLLLLLEAAAASEEE! You will get hosed.

And there's the possibility that a tps or temp sensor connector also had a bad connection causing the glitch. Sometimes you can get rid of problems like that by reseating all of the sensor connectors that you can get to. It also works for glitches with the antilock brakes, and anyone can do it. If you don't know what's wrong with the car, it's something you should do before throwing money at it. Don't forget that solid state electronics are more reliable than mechanical parts such as connectors.

[Injuneer]

94 is not Speed-density.... its mass-air.

The fan comes on for some of the SES lights, but not all.

Code is stored... get it checked fast, before it self clears. Do not under any circumstances try to "clear" it yourself. You will lose a valuable piece of information.

The jumping tach may indicate an electrical problem. Could be as simple as a bad ground, could be weak battery voltage, or it could be part of the igntion system, including an IC Module that is becoming heat sensitive, or an Opti that had trouble producing the correct high resolution pulse.

Bad connectors... yes, the most notorious is the MAP sensor connector, which will start to crumble with old age.... just like me.

[Jeff_in_Atl]

Mine did the same thing when the OPTI went out. Actually I'm not sure if the internals to the OPTI were bad or not but the connector and the wiring harness were corroded and it was making intermittent contact. My tach was going nuts too. I tried starting it for several minutes and it wouldn't start. I got out and started looking around, just sort of wasted some time, got it and it fired first time. It ran like nothing was wrong. About 2 days later, I was driving home and it started spitting and sputtering real bad. No power at all. The tach was bouncing between 0 and 6,000. I pulled off and tried to start it for several minutes. I waited several minutes and it fired right up. I thought it might have been heat related and let it cool off. No it was the connector to the OPTI.

I don't know how you could get to this connector with the water pump on it but if you can, you might find the problem there.

Here is something you can do without getting it scanned.
http://shbox.com/1/4th_gen_tech2.html#opti_test

As you can see from the above posts, it can be a lot of things. Your going to have to daignose it or you could throw a lot of money at it without fixing it. The first step is to get it scanned.

[Blazer]

You said when you hit the brakes the engine would die. My Camaro did that an it was looking for a ground. Clean the ground cable. Just my two cents. Good luck.

[Craig 94 TA GT]

Thanks so much guys for the info and help. I will get it scanned ASAP today before the code is gone. I guess I'll go from there and try to follow all your suggestions.

[Craig 94 TA GT]

I got another quick question...
I've been trying to find places that will scan codes but I can't seem to have any luck. I called Kragen, and they don't. The nearest Autozone is 25 miles away, and I don't think I'll push my luck that far. Carquest doesn't do it either. Pep Boys says they'll charge $90 just to scan it. Is a local shop the only way to go?

[Jeff_in_Atl]

I don't know except the Autozone and Advance auto here can only scan OBDII computers which leaves out the 95 and older V8 F-Bodies. I bought a scanner. I think it is the best tool you can buy for a car these days. I bought one of these http://www.autoxray.com/