Problem

[gobluebrett]

Hi, this is my first post here and I would just like to say that I am glad that I found this site. Sorry if this problem has been brought up before, but I searched and didn't find anything, so here goes. My problem is that when I start up my car, it always sputters to life and sometimes even sputters so bad that it stalls. And then it jerks pretty hard. This is really annoying and while it is jerking it runs like crap. After about 2 minutes, the engine comes to life and runs normal. I know that this problem is not the engine because once the engine is running properly, it runs like a dream. Also, when my car has been running for awhile and I park it at a store and come right back out, I have trouble getting the car to start without having to give it gas. Both of these problems lead me to believe that there is something wrong with my fuel injectors or fuel system somewhere. But my grandpa, who owned this car before me, took it in and they checked everything and said that they had no clue what it could be. It is worth noting that when I put fuel injector cleaner in the car, the car runs smoother for a day or two but then reverts to the way it was before. BTW, I have a '94 SE with the 3100 V6. Please help me if you know what it could be. Thanks in advance.

Brett

[RocketFast321]

I'm guessing fuel filter, it only cost like $10

[gobluebrett]

Thanks for the reply. Not to sound mean or disrespect you, but wouldn't the shop have checked that though? I don't mean to contradict you, but thanks. I probably will try that and see if that is what it is.

[RocketFast321]

Maybe, look under the back of the car to see if it looks new.

No disrespect taken :)

[gobluebrett]

Yup. Thanks a lot. If that is all it is, then that would be great because when the engine is running good it is very quick even at its age.

[voyager]

the fuel filter isn't really something they would take off and 'check' - if it's old, you replace it. cheap part that should be replaced every so often anyway. it's my guess too.

if it's not that, i would check the spark plugs next. you can have a misfire when the car's cold that goes away when it's hot; if the shop checked once the engine was warmed up they might have missed it.

good luck...

[gobluebrett]

Okay, thanks. I think that replaced it, but I will try it anyway. Thanks guys.

[true_cal]

It seems as if your vehicle is having problems with "closed loop" operation" ... this means the engine will run on preset values set by the PCM until the engine reaches a preset "operating temperature", then it will run in "open loop" meaning the PCM will moderate spark/fuel etc. according to inputs by the engine sensors. I think your problem ( if not a fuel delivery or spark problem ) may be with your PCM (engine computer), this just means that you need you computer re-programmed by the dealer.
Another thing to check on the fuel system is the evaporative emissions control system ( this system takes care of fuel that has been evaporated, but not used by the engine... this system stores the evaporated fuel until it can be used by the engine again... prevents gas fumes from evaporating into the air and causing potential fire/explosion)

... be sure to check fuel pump for operation along with the fuel filter. (before starting the car, leave the key in the "on" position for 5 seconds, then start the car. you should hear and electrical noise come on then cut out (its the fuel pump building up the necessary pressure, the cutting off once the operating pressure is reached).

... make sure spark plugs are the proper ones with (AC Delco) with the proper gap set. also check all spark plug wires & boots are in good shape.

... make sure EVAP system component are in good shape (check hoses, wires, etc.

... check the distributor cap/ coil packs for any cracks or damaged wires.
---------------------------------------------------------------------------------
... then bring it to the dealer and mention the possibilty of a "closed loop" operation problem.

... keep me updated, im curious of whats causing my problem.

[rixGAphx]

I agree with true_cal's "Closed-loop" scenario.

The only 'sensor' that is working during closed-loop is TPS (Throttle Position Sensor).
Since the engine runs fine after warm-up, the TPS isn't the problem.
The only thing left is the PCM (Powertrain Control Module, the engine 'puter).

I assume you get no 'Check Engine' light.

Good luck.
-Rick

[gobluebrett]

Thanks for the replys guys. Rick, no, I don't get a check engine light. True_Cal, thanks for the reply. I think that it is very possible that it could be the computer, even though my grandpa has had it fixed, but maybe that dealer was incompetent and didn't know what they were doing. I don't know how much of this I will be able to afford because I am only 16 and paying for insurance and everything else. The fuel filter is about the only thing I can afford. Once again, thanks.

Brett

[rixGAphx]

Originally posted by gobluebrett
...I don't know how much of this I will be able to afford because I am only 16 and paying for insurance and everything else. The fuel filter is about the only thing I can afford. ...
If you're anywhere near a large metropolitan area, call a local junkyard and get a price for a slavaged PCM for your exact GA year and engine (tranny and level-of-trim are irrelevant).
Even if that junkyard doesn't have it, he has internet access to all other local yards and can find one.

Prolly cost about $30, with 10-day warranty.

Snap it in: If it works, you're good to go.
If it doesn't, return it and you're only our a few hours running-around time.

Also try e-bay.

just remember, ONLY '94 (and mebbe '93) will work for your car. Nothing newer.

good luck.
-Rick

[gobluebrett]

All right. Thanks. I might give that a try if the fuel filter doesn't work. Thanks.

Brett

[voyager]

one thing you might try is resetting the PCM. on my car, to do this you disconnect the battery for 15min or so, then reconnect the battery, start the car and let it idle ( or drive it ) for two fan cycles - i.e. until the fan has automatically kicked on twice - the closed loop idle settings should be relearned. i don't know if the procedure is the same for GA's ... ?

at any rate an idle relearn is free.

i agree the problem is in closed loop - the car runs according to presets until the engine reaches operating temperature.

[true_cal]

I hear you with the cost of insurance! ....im 17 and pay $183 CA per Month... when i fixed the head gasket i had to take the car off the road for 3 1/2 months to pay for the parts! thank god i did the labour myself! ... good luck with your car, i know what its like to have car trouble and have no money.

[Colin]

Originally posted by true_cal
I hear you with the cost of insurance! ....im 17 and pay $183 CA per Month... Good Lord .. :eek:

[gobluebrett]

Voyager, I might try that. That sounds pretty easy. That would maybe fix the problem of it not starting when it is warm, but will that also fix the problem of it running extremely rough for a few minutes even when it has been sitting for awhile?

BTW, i replaced the fuel filter and it changed absolutely nothing, so it probably is the computer. Once again, thanks guys.

Brett

[gobluebrett]

One more thing, how do you unhook and hook back up the battery on my car? Sorry if I sound dumb, but I really know nothing about cars and am trying to learn more.

Brett

[RocketFast321]

Originally posted by true_cal
I hear you with the cost of insurance! ....im 17 and pay $183 CA per Month...

is that alot or somthing? :P I pay $517 every 3 mouths, and with me be the main driver on the malibu. if i was the full driver it would be 1,000+

[rixGAphx]

Originally posted by gobluebrett
One more thing, how do you unhook and hook back up the battery on my car? Sorry if I sound dumb, but I really know nothing about cars and am trying to learn more.Brett
You REALLY need to get a Haynes or Chilton's manual for your car.
The front chapter has a wealth of information on general automotive stuff, almost equal to a semester of high school auto shop.

Batteries:

1. Be careful!! There is strong acid and lots of electricity involved.
Enough to spark an explosion, blow-up acid into your face, or arc-weld your class ring to both your finger and the battery.

2. ALWAYS disconnect the ground terminal first. On EVERY modern car, 'ground' is Negative (-), and convention says the cable and everything around it should be Black.
If your hand slips on the wrench and touches the metal of the car, it will NOT short out (since it's already connected to the metal, that's the meaning of 'ground).

3. Positive (+) is Red. Loosen this only after the Neg is disconnected.
If the wrench slips and the Neg is still connected, a strong battery produces about 60amps of 12vDC power, thru that wrench and your hand, and a ring or watchband.
That's more power than it takes to weld structural steel. It's enough to melt gold into your flesh.

4. There are many idiots in the world who will reverse the colors of the cables, or buy the wrong color.
Don't be one of them, but be aware they might have already touched your car.
Use safety glasses to prevent acid splash into eyes.

Are you suitably scared? Good, you should be, this is dangerous stuff.

5. Using a 5/16" hex box wrench (they sell a special one in the Battery section of the autoparts store), loosen the bolt on the Neg (-) side terminal. Remove.

6. Repeat for Pos (+).

7. Clean everything, using a paste made of baking soda and water. Rinse with clear water. Sand, wire brsu, file the metal of the terminal and the bolt threads and the metal connection surface of the battery. Dust away the shavings and debris.

8. Reconnect Pos (+).

9. Reconnect Neg (-).

Hope this helps.
-Rick

[gobluebrett]

All right. Thank you

[true_cal]

Thats true, Battery safety can never be emphasized enough!!!
I used to be terrified of car batteries until i worked on (and with) plenty... and quite frankly, i am still scared of what they can do!

... i had a bad experience where me and some buddies were tearing a car apart for a demolition derby and we were anchoring the battery., well .. the insulation on the batteries cables were deteriorating and the metal material used to anchor the battery made contact with the pos (+) and sparked, and melted all metal around it and the battery started emitting fumes. The achor become red-hot! ...
so like rick said... check EVERYTHING!!!

[gobluebrett]

Ok. Here's an update. I did the battery thing but it did very little, if at all, to fix the problem. So, I think that I'm going to get a test done at Autozone and if it is the PCM I will probably replace it. THanks for all your help.

Brettt

[HeyDace]

Good call True-cal, except "closed loop" is when the engine is running at operating temp, "open loop" is when the engine is cold and the ECM subs preset values. (you just had it backward). :)

Gobluebrett's problem sounds like a fuel issue. I'm assuming all the basics were checked along with fuel pressure and delivery. If nothing was found, his problem may be due to low volitility (sp) fuel, since it seems to run better on an additive like injector cleaner.

A '94 3.1 liter when new will run on 87 octane with no problem, but as years and miles go buy, compression and combustion decrease, especially when its cold.
Before you start blowing money on diagnostics here and there, try running a couple tanks of 97 and see if it makes a differance. If it doesn't and the problem still cannot be found, try cleaning the throttle bore and resetting minimum idle speed. I've had good luck back in the day with doing that (I had a '93 Grand prix).
Do a search, I think we've discussed this procedure before.

Good luck

[gobluebrett]

HeyDace, based on the info I am getting from your post, do you mean that nothing is wrong with my PCM at all and that it is the fuel system only? Because I had my friend's dad look at it and he said that it most likely was the PCM. Thanks.

Brett

[gobluebrett]

All right guys, here's an update. I took 'er in to an auto diagnostics place. They said that the EGR Valve was bad, and that it should be replaced. I said ok, so they did it. That completely fixed the problem!! I am so happy now. Thanks for all your help guys and I just figured I would let you know how it turned out.

Brett