Car suddenly runs like crap!! Runs rough and weak

DJStillman · Nov 27, 2004

Hey all:

1991 Acclaim 2.5 3-speed, 133,000 miles. Car has been running pretty well, getting around 25ish MPG, pretty smooth on the highway. Gauges read normal, computer has no codes. Basically, no indication of any problems. Tuneup done about 1 year ago, regular oil changes, 87 gas (some knocking under load). Timing belt and tensioner changed about 9 months ago. Front and passenger mounts just replaced. Revs fine, though a little weak on the upper end.

All of the sudden today, I started it up, and it ran really rough. Engine shaky, harder to rev, weaker. Basically, a totally different car. This was not the first start of the day, it was about the third.

I have tried different known good (albeit old) spark plugs, I have flipped the contact sides of the wires in the cap, I even cleaned the rotor contact. I tried running the car missing one wire for each start. Thinking that there was a bit if crud somewhere, I even ran some water slowly through the brake booster hose.

I have to admit, I am a bit lost here. Please help. I reeally need this car to be running well, because I use it to get to school.

I eagerly await all suggestions and ideas.

David

Ken42 · Nov 27, 2004

Does that have the Throatle body injector? TBI for short? Check out that injector.

Amkeer · Nov 27, 2004

Fuel filter.

Virtuoso · Nov 27, 2004

I hate to say it, but the 2.2 (your 2.5 is a stroked version of) in my old '88 Sundance did the same thing - it was a blown headgasket. Pretty common ailment of these engines; especially with your milage.

It would run fine for awhile, then for a short bit it would run like crap..like it only had two or three pistons firing (in effect it did). Did this off and on for a couple weeks and then finally **** the bed.

You may want to get a compression check.

DJStillman · Nov 27, 2004

quote:

Originally posted by Virtuoso:
I hate to say it, but the 2.2 (your 2.5 is a stroked version of) in my old '88 Sundance did the same thing - it was a blown headgasket. Pretty common ailment of these engines; especially with your milage.

It would run fine for awhile, then for a short bit it would run like crap..like it only had two or three pistons firing (in effect it did). Did this off and on for a couple weeks and then finally **** the bed.

You may want to get a compression check.

I had been worried to hear that one. Would you do a check on your own, or go to a mechanic? Any idea how much a check would cost?

55Test · Nov 27, 2004

Check your oil, if it looks like a chocalate milkshake then you'vr got coolant getting into your oil, also check your coolant to see if there's an oily film on the surface. Also, when the car is warm, check to see if there are any bubbles coming up into the overflow tank. Check out www.allpar.com if you want to find more info.

DJStillman · Nov 27, 2004

quote:

Originally posted by 55:
Check your oil, if it looks like a chocalate milkshake then you'vr got coolant getting into your oil, also check your coolant to see if there's an oily film on the surface. Also, when the car is warm, check to see if there are any bubbles coming up into the overflow tank. Check out www.allpar.net if you want to find more info.

Oil is clean, coolant too. No bubbles in overflow. Have been a member of Allpar for a year and a half, and already have a similar post there. Thanks, though.

55Test · Nov 27, 2004

Well I guess the headgasket isn't your problem. Have you checked for codes? Could be a bad sensor.

DJStillman · Nov 27, 2004

quote:

Originally posted by 55:
Well I guess the headgasket isn't your problem. Have you checked for codes? Could be a bad sensor.

Only a 55 - end of codes. Oil, temp, and volt gauges read good, too.

Virtuoso · Nov 27, 2004

How long has this been going on? Is it still happening?

Could still be a headgasket - mine didn't turn my oil into a milkshake until it really lost it.

I would do a compression check yourself. That engine is pretty easy to work on and the proper gauge should be pretty cheap (if not rent-able) at an autoparts store. Not really sure how much a shop might charge, perhaps an hours worth of labor (usually around $80 here)?

DJStillman · Nov 27, 2004

quote:

Originally posted by Virtuoso:
How long has this been going on? Is it still happening?

Could still be a headgasket - mine didn't turn my oil into a milkshake until it really lost it.

I would do a compression check yourself. That engine is pretty easy to work on and the proper gauge should be pretty cheap (if not rent-able) at an autoparts store. Not really sure how much a shop might charge, perhaps an hours worth of labor (usually around $80 here)?

It literally started today. I guess I am going to have to go find a compression checking tool.

ZR2RANDO · Nov 27, 2004

Look for some vac lines that may be cracked/split/loose. Bad sensors/connectors should show a code. Does it have prob on cold start? or after warm up?

Gary Allan · Nov 27, 2004

quote:

Look for some vac lines that may be cracked/split/loose.

That would add up with the rough idle and ...

quote:

pretty smooth on the highway.

DJStillman · Nov 27, 2004

I have already checked my vacuum lines, and they are still pliable and tight. No vacuum hiss anywhere. Also, it is a very simple vacuum system, so leaks are easy to detect.

This was a totally spontaneous problem. Since I had no problems before, and have not messed with anything under the hood for over a week, I do not understand how my problem could be a vacuum leak.

Thanks, and keep 'em coming!

ZR2RANDO · Nov 27, 2004

It was "pretty smooth on the highway." before, but not now right? Maybe distributor vacuum? I have seen vac lines with small cracked ends work loose by themselves, just showing some age...
They are just a good usual suspect for sudden rough running issues. Looking forward to hearing the answer.

eljefino · Nov 27, 2004

The distributor has no vacuum but the map sensor does! The hose that goes to it makes several sharp 90 degree turns; just replace it with a new one, it's 50 cents for two feet, it goes bad and will probably crumble in your hands. As the map sensor is the main load-sensing widget, a leak in that line is a double whammy.

cousincletus · Nov 27, 2004

Try replacing your MAP sensor. Seems to be a common problem with Chrysler 4 cyl. engines and all of the sudden engine starts running like cr@p. Have seen them go bad on late 80s 4 cyl. engines and the symptoms are the same as you describe. Although I hate to throw random parts at the problem, the MAP sensors are such a common problem I would try it.

michaelc80 · Nov 27, 2004

Check the wiring to the sensors and engine for loose connections. Also double check the grounds-make sure there's no corrosion.

I have a Sentra that for no reason would start bucking and trying to stall. Finally determined that the ground wire between the engine and chassis had broken. Replaced it and problem was solved.

DJStillman · Nov 27, 2004

quote:

Originally posted by eljefino:
The distributor has no vacuum but the map sensor does! The hose that goes to it makes several sharp 90 degree turns; just replace it with a new one, it's 50 cents for two feet, it goes bad and will probably crumble in your hands. As the map sensor is the main load-sensing widget, a leak in that line is a double whammy.

Hose is less than a year old, is a double thick dealie, and has been checked.
It is tight and pliable, no cracks.

DJStillman · Nov 27, 2004

quote:

Originally posted by cousincletus:
Try replacing your MAP sensor. Seems to be a common problem with Chrysler 4 cyl. engines and all of the sudden engine starts running like cr@p. Have seen them go bad on late 80s 4 cyl. engines and the symptoms are the same as you describe. Although I hate to throw random parts at the problem, the MAP sensors are such a common problem I would try it.

Wouldn't the MAP sensor throw a code in my computer?

Car suddenly runs like crap!! Runs rough and weak

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