Car Problems...

[Dr_Deathweed]

I need help form all of you pro/home mechanics out there...

My 1993 Oldsmobile Cutlass Supreme T up and died on me on Sunday. It started vibrating badly and stalled after only running for ~5 minutes. I checked to see if the exhaust was clogged but it seemed to put out plenty of gas when running, but a lot of black soot as well. I pulled the spark plugs, and they were fouled as well. I will clean them when I get a chance, but I am wondering why I am running rich in the first place.

The plugs and air filter are only 6mos old, and the air filter is clean. The air intake is also clear, and the spark plug wires are brand new a couple of months ago. There is no check engine light, so I believe the O2 sensors are fine, but will check them with a volt meter when I get time.

I am starting to lean toward either a distributor problem, or excess fuel pressure. My last oil change about 3 months ago ended up cutting the wires to the fuel pump (whatever idiot at GM decided to run those wires right under the oil filter.... grrrrr.... one wrench gets away and YANK!) There is a small possibility I swapped the wires on it, because the color coding was funky, It looks like this had happened a couple times because those wires had been spliced a couple of times.

If anyone has ideas, PLEASE let me know, I had rather do this myself than take it in for a repair that may cost more than my vehicle is worth...

 

[BuffaloSabresBrewer]

Wish I could help you more but....
heres a bump!

 

[GilaMinumBeer]

It's a 93 Cutlass. I thought they were supposed to growl and puff smoke?:rockin:

 

[RICLARK]

Sounds like, A) the Fuel filter is plugged B) The Fuel Pump is bad C) The Coil Pack could be bad.

 

[Klainmeister]

Coil pack is a good thing to check. Just out of curiosity, which engine is it? I've worked on a lot of cars, mostly foreign though, so I don't know the engine off the top of my head.

 

[MikeFlynn74]

Sounds like, A) the Fuel filter is plugged B) The Fuel Pump is bad C) The Coil Pack could be bad

Coils either work or they dont.

Plugged filter wouldnt give the impression its running rich. Id check to the if the Idle Air sensor is bad or crank/cam angle sensor

 

[dirtymike1]

Nope Nope and Nope.... Since you ripped the wires to the fuel pump, if they were wired up wrong after you fixed them, the pump would not work. So thats check one. Fuel pump rarely "start to go bad". They are one thing that is either working on not working. Check 2. Clogged fuel filter. This would limit the amount of fuel going in, so you would more then likely be running lean. Check 3.

Hmmm... Try pulling the distirbuter cap and look for any white burn marks. If they are present replace the cap and rotor. if not, close and move on.

I would try gonig to the store and buying a can of Sea Foam, ask for it by name. Put it into your gas tank right before you fill up, fill up then run the tank to damn near empty. This will clean out your fuel injectors as well as the lines. I would also replace the filter just for good measure.

This is a start, and this is also 5 years of experiance behind this.

 

[RICLARK]

Coils either work or they dont.

Plugged filter wouldnt give the impression its running rich. Id check to the if the Idle Air sensor is bad or crank/cam angle sensor

I have had plugged filters cause both Shaking and stalling and Bogging way down, it is definatley a possibility.

 

[dirtymike1]

Coil pack is a good thing to check. Just out of curiosity, which engine is it? I've worked on a lot of cars, mostly foreign though, so I don't know the engine off the top of my head.

No Coil Pack, its got a cap and rotor

 

[homebrewer_99]

Sounds like a hit and miss sparking...distributor cap and rotor are my guess...

 

[RICLARK]

Does it have a throttle Body, or is it full Fuel Injection? It could be flooding itself out and fouling the plugs.

 

[Dr_Deathweed]

To start answering questions:
- It is a 3.1 L 6 cylinder engine, and unless I am GROSSLY mistaken, it is fuel injection
- fuel filter was replaced 6mos ago when I did all the other work on the vehicle
- I run injector cleaner every 3 months.. Or I have been for the last year or so. I cant vouch for any maintnence before that.
- Don't think its the idle sensor, wouldnt I get a code for that? It also idles fine, It is when I get moving, or start slowing down after driving that it starts shaking bad and stalling

I will deff check the distributor tonight. I orriginaly thought it was a clogged cattalytic converter, but the amount of exhaust coming out kinda dismissed that one. The distributor is rapdly becoming the prime suspect.

Please keep the ideas flowing, so when I get home I cam make a more efficent use of my time

 

[RICLARK]

To start answering questions:
- It is a 3.1 L 6 cylinder engine, and unless I am GROSSLY mistaken, it is fuel injection
- fuel filter was replaced 6mos ago when I did all the other work on the vehicle
- I run injector cleaner every 3 months.. Or I have been for the last year or so. I cant vouch for any maintnence before that.
- Don't think its the idle sensor, wouldnt I get a code for that? It also idles fine, It is when I get moving, or start slowing down after driving that it starts shaking bad and stalling

I will deff check the distributor tonight. I orriginaly thought it was a clogged cattalytic converter, but the amount of exhaust coming out kinda dismissed that one. The distributor is rapdly becoming the prime suspect.

Please keep the ideas flowing, so when I get home I cam make a more efficent use of my time

Since it is not a throttle body, My next vote goes to the distributor as well.

 

[Dr_Deathweed]

Since it is not a throttle body, My next vote goes to the distributor as well.

Actually now that I think about it, it may have a throttle body.... If someone could double check to see which is standard on this model that would be awesome...

I am nowhere near the car, and trying to study for a radiology final, so I will try to answer questions throughout the day, and I will give some updates when I get back home this evening.

Thank you everyone for your help already!

 

[CodeRage]

If you're running that Rich you are either not getting enough air or too much fuel. Bad spark is a possibility. I would pull the injectors and have them checked. They are 15 years old and that is a alot of life to get out of them. I wouldnt be surprised if you have one or a couple leaking a fair amount. Could be an ECU issue but I would run down the injectors first.

EDIT- Oh! Seafoam is the shiznit! Run half a can into your break booster line while the engine is running and let it sit for a half hour and restart. You will clean all kinds of carbon deposits out! The thing willblow all kinds of nasty smoke for a while but it got rid of my spark knock and cleaned the valve stems up super nice. Marked improvement in air flow.

You're not loosing oil are you?

 

[MikeFlynn74]

Don't think its the idle sensor, wouldnt I get a code for that

not always- If its running within normal parameters it wont set a code.

It may be stuck- also you might have a Mass Air Flow sensor as well.

Ever replace your 02 sensor?

 

[dirtymike1]

Since it is not a throttle body, My next vote goes to the distributor as well.

I think you mean Carborated. All cars have a "throttle body" in one way shape or form.

Pull the Dist. cap off tonight and see what it looks like. If you think it's the Cat. then put a thermomitor up to it. Get the car up to operating temp. Check the front of the Cat then the back. There will be a differance in temp, if I remember correctly the back will be hotter. If there is a gross differance in temp., I'm talking 100 degrees, then the cat would be bad. You really need a no-touch laser thermo. to do this. If you just put your hand behind the tail pipe and you feel good flow, then this is proboly not your problem

 

[Yuri_Rage]

Nobody's mentioned it yet - slipped timing belt?

 

[shafferpilot]

Many years of auto experience tells me this is an ignition problem. The "rich" appearance is the result of a cylinder not firing for several cycles, then finally firing with lots of extra fuel in it, and then the extra fuel in the exhaust burns, albeit innefficiently, and makes a bunch of black smoke. I'm gonna go with distributor cap and button. BTW did these symptoms come on slowly, or just start happening all at once? Lastly, are you 100% sure that you didn't get diesel fuel in the tank? Crazy, I know, but I've heard of that happening around construction sites and stuff when someone thinks they can get free gas out of a fuel barrel.

 

[dirtymike1]

Nobody's mentioned it yet - slipped timing belt?

It doesn't sound like a timing issue to me. It's is possible, but this sounds like an air/fuel ratio problem

 

[Yuri_Rage]

It doesn't sound like a timing issue to me. It's is possible, but this sounds like an air/fuel ratio problem

I only mention it because the symptoms are exactly what happened when I mistimed a car I worked on in college (only off by a single tooth, IIRC).

 

[MikeFlynn74]

The throttle position sensor will also cause those symptoms

This is what I was trying to think of. I bet 50$ its this.

Many years of auto experience tells me this is an ignition problem. The "rich" appearance is the result of a cylinder not firing for several cycles, then finally firing with lots of extra fuel in it, and then the extra fuel in the exhaust burns, albeit innefficiently, and makes a bunch of black smoke. I'm gonna go with distributor cap and button. BTW did these symptoms come on slowly, or just start happening all at once

Its not like that on EFI cars- It just doesnt work like that. The O2 sensor would account for it and greatly reduce the fuel to the injectors.

 

[MikeFlynn74]

the 3100 has a Timing Chain I believe

 

[Yuri_Rage]

the 3100 has a Timing Chain I believe

Nevermind, then...

 

[MikeFlynn74]

GM lineup (2.0/2.2L, 3100, 3300 and 3800 V6; 5.0, 5.7L and 7.4L V8, etc.) are all pushrod engines that use a traditional timing chain and gear set to turn the cam

 

[Dr_Deathweed]

shafer- I may of had some stumbling in the past,but the violent vibrations and stalling came on suddenly.

Yuri - I am pretty sure that my car has a timing chain, and if thats the problem, I may think aboug just shelling out for another new-to-me car

dirtymike - I do have good flow out of the tailpipe, but if I can get the car to run long enough w/o stalling or risking further damage I will check the catalytic converter

 

[MikeFlynn74]

throttle position sensor

I bet you money its that. Cheap and easy to fix

 

[Dr_Deathweed]

As of now, I will check the distributor when I get home.


MikeFlynn - Got a good way to check the throttle position sensor?

 

[MikeFlynn74]

unplug it see how it runs-

Throttle Position Sensor - Testing

Set DMM to read DC Volts.

Connect black COM lead probe tip to the TPS ground wire.

Connect red Volts lead probe tip to the TPS Reference Voltage wire.

Turn ignition ON. Do NOT start engine.

Look for a 5 volt reading - (some manufacturers may differ - verify correct reference voltage for the specific vehicle being tested).

If reference voltage is too high or too low, look for a problem with the wiring harness or PCM.

After establishing reference voltage is O.K., connect the red Volts lead probe tip to the TPS to PCM signal return wire.

Look for low voltage at idle position that will smoothly increase as throttle is applied. Any fluctuation of the DMM Bar Graph or erratic voltage readout indicates a bad sensor. Verify factory specs for low voltage (idle) setting, even one tenth off can make a difference in vehicle performance. The high (full throttle) voltage should reach at least 80% of the reference voltage.

Turn ignition OFF when test is complete

 

[Dr_Deathweed]

Oh yeah MikeFlynn, in response to a post a while ago, I have not replaced the O2 sensors, but I am not getting a check engine light either. I will replace them eventually since I do have about 140K on the car, but if you think it is a good idea to do it wether they are the problem or not, I may go ahead while I have the tools out.

Of course I am putting off changing these after having to replace the exhaust manifold on my sisters car after pulling out her O2 sensor.....