mav75

So I'm driving to work today going about 85 on the highway at 2,000 RPM when all of a sudden, the engine started sputtering, losing power, and finally stalled out on the side of the road.

After a couple attempts at restarting, I got the engine to come back, but it wasn't pretty. Every time I would put the car in gear, I'd get zero power, the revs would go wild, (but wouldn't go above 1,000), and I'd stall again. The best I was able to do was about 5 miles per hour with the gas pedal was basically floored and the revs still all over the place.

Last week I tried passing someone on the highway. As soon as the needle hit 3,000, the revs dropped immediately to somewhere between 1,500 and 2,000. The engine still ran strong, but would not go over 3,000 RPM or give me any kind of real passing power.

I don't know how to fix cars, and I'm not going to pretend I do. Having said that, I have a couple of theories. I've been reading this forum a lot lately, and I've seen a lot of complaints about 3rd gen fuel injection problems. I'm thinking I probably have a clogged fuel filter or one (or more) clogged fuel injectors. Is it a good idea to replace all 8 injectors? If so, do the fuel lines need to be changed also?

This engine has less than 48,000 original miles on it. The car is an '89 Trans Am that only one other person has had before me. I got it in June. The seller included maintenance records, and none of them show any major maintenance. So I have no idea if anything major was wrong with the car when he sold it. I doubt it though. This car was babied for 21 years, and it seems to have spent most of that time parked.

I wonder if any other maintenance might be a good idea at this point. All I've had done to it was convert the A/C from R12 to R134 (it needed to be charged) and I've had the serpentine belt changed. I'm thinking I could use a tune up (new plugs, wires and a distributor cap). I wonder if the brake, radiator or tranny fluid needs to be flushed.

Does anyone think I'm going overboard with this, or am I missing something else? Any opinions would be more than welcome, since I don't really want to get raped by the shop I had the car towed to.

dustpusher

I would try to pull the codes if the check engine light is on.It sounds like the tps is bad to me.

8t2 z-chev

sounds like a bad fuel pump or an electrical problem
affecting the voltage to the fuel pump(bad connections,
etc.)If the CEL lit check for codes-could be a bad TPS
but on my C/F at least,a bad tps caused a few hiccups
and lit the CEL but did not cause anything as bad as you
describe.
Have the shop check the fuel pressure if there are no
stored codes.

mav75

Thanks for the input...not to sound like a complete moron, but what's a TPS?

jwande

Throttle position sensor - it tells the computer where your throttle is position-wise and then the ECM (electronic control module or computer) sends signals to open or close the injectors.

jwande

Check for SES (service engine soon) codes before you start throwing parts at it.

mav75

Thanks for all the info (and not calling me a dumbass!) everyone! I'll update when I hear from the shop.

mav75

Update --

The shop is in the process of replacing the fuel pump. They said the fuel pressure dropped when the engine was warm and the transmission put in gear. I grilled them about whether my injectors were acting up and they said no, they tested each one individually and found no clogs or computer issues.

They're also doing a tune up. Apparently the plugs, wires and cap are all original.

Everything should be done tomorrow, but I won't be able to pick it up until Monday.

I'd like to say that this will be the end of my troubles, but I doubt that...

DukeofHurl

I know when my throttle position sensor went out the car had no power on the highway and would sputter and backfire doing 50 or so. I remember even having to pull off of the highway and turn the car off and back on after a couple of minutes and then it would get home but still not run well. If you end up needing to go that route search this forum on calibrating your tps after replacing and maybe check the calibration on your IAC, I know they can cause all kinds of problems for you. Sounds to me like an electrical gremlin rather than a physical motor problem.

Roger Davis

A bad injector (just one) can do this same kind of thing...

mav75

Duke, the shop said they would check and clean the IAC if there was too much of a buildup. Haven't heard back on that yet. I'm thinking Roger is probably right about me possibly having a bad injector, even though the shop says it's testing fine. Maybe I'll get lucky with the tune up, fuel pump, flushing out the fuel system, and replacing any clogged or dirty filters. We'll see. What should a set of 8 installed OEM (or close to OEM) fuel injectors run me?

J91

It's most likely the fuel pump...

southbay08

We can give you a set of 19lb direct fit bosch lll's. They normally run $155 for the set,,,but all tgo members receive a 10% discount with code TG11. If we can help you in any way please do not hesitate to contact us

www.southbayfuelinjectors.com
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Roger Davis

On the first go-around, I did all the things you mention and more. No fix.

One way to trace a bad injector that tests good is to disconnect the wires to the injector temporarily and drive the car, repeat the next one, repeat the next one, etc. . When you find 7 good cylinders worth of performance and one disconnected, you have found it, if an injector is the problem.

On the first occasion, mine all tested good in every way they could test them. A "real mechanic" tracked it down as above.

mav75

I asked the mechanic to replace the injectors. My logic is that before the "real" problem started, all evidence was pointing to one or more clogged or bad injectors. The injectors in the car are the original, 21 year old injectors anyway. Also, if one is bad, it's probably a good idea to replace the whole set.

Southbay, thanks for the offer. My mechanic is shopping around locally to see if he can match or beat it. If not, I'll send you a PM.

southbay08

Not a problem mav75, we are here if you need us

JTNKTZ

iTrader: (10)

That sounds like the oil pressure switch. When warm the oil gets warm and the switch doesn't switch it. I had that problem before... What was the oil pressure reading?