ren495

I have a '92 with 215k miles. About 1,5 months ago I was driving on the highway and it stalled. Started rigth back up, but the engine was jerking and sputtering. Nearly stalled, then jerked forward. When I pressed the gas pedal there was no power for a while, then it would jerk again. I shut it off, waited for a little, then started back up and drove 80 miles with no problems to my location and then back 300 miles with no problems again. I figured maybe it was the Arco gas I put in that one time, filled up with Shell premium and since it drove fine for ~400 miles thought it was OK. Until last week when the sputtering came back. I changed the spark plugs and wires, drove it around for 40 miles, ran like new. Then I left it to idle for 5 minutes, and it started sputtering again. No power when I accelerate followed by short jerks (but does not stall and starts up perfectly). Then after a short while of sitting it runs fine again.

I also have a 2000 LS400, so the '92 has been sitting around a lot the last 3 years. I've driven it maybe 10,000 miles the last 3 years, mostly highway driving.

Could it be a fuel filter? Fuel injector? But would it not work at all in that case, and idle rough? It runs very good except a few times since april when this has happened.

I'm in graduate school, so I don't want to buy a new car until after I'm done. And me and my girlfriend need to cars. If the '92 could last me couple more years it would be perfect! Any ideas what the problem could be?

python

iTrader: (4)

how old is the gas?

ren495

its not old. So far this year i've driven the car 4 times on the highway, 300 miles each trip. 3 times in the last 2 months. So I had to fill up when I did that, plus I filled up again after it started sputtering because I thought the gas was bad. When the car first stalled and sputtered, some of the gas could have been ~4 moths old. But when it did it again last week, the gas was few weeks old at the most.

I should probably change the fuel filter anyway, just to see if it helps (I bet its never been changed)

JimsGX

I've experienced the same problem on a 91LS. For me though, its always happened when it was hot out and most of the time when I've let the car idle for 5~15 minutes, then tried to take off and it sputters and has no power. For the most part, it will still idle, but when you give it the gas, it would just cut out. I've made several changes and it hasn't occured in some time, so I can't be sure which one of them fixed it but I ran Chevron Techron through it for a couple of tankfuls, cleaned the Mass Air Flow Sensor (MAF), changed the air filter, and have installed all three new catalytic converters. I didn't change any of the oxygen sensors. So far so good...

Jim

ren495

Thank you JimsGX, that helps a lot. I changed my air filter, MAF sensor was clean (it's that little black plastic box on the air assembly?). Cat. converters could be the problem though. I didn't even think of that before.

This starts happening to my car also when it is idle. The first time it happened on the highway at 70 mph, but ever since then it has happened when I was at a really long red light or I left the car to idle in my driveway.

JimsGX

Correct on the MAF... I think my two Cat's off the manifolds were in pretty tough shape. The passenger side one ended up rusting out about 3/4" above where the oxygen sensor screws in, so I replaced both of them. One thing I had noticed prior to this was that the two front fenders would get extremely hot if the car was left to idle in warm weather (even at night, so the sun wasn't a factor). I never saw the cat's glowing red like some others have reported when they were junk, but I'd bet an egg would have fried on the fenders if given enough time.

Have you noticed this at all on either of your front fenders?

ren495

They don't get that hot, but they definitely get warm. I just drove around and then left my car in idle for 20 min. The hood was cold but the fenders, especially towards the front, near the head lights, were getting really warm.

All signs are starting to point towards the cat-s. It's a life saver that you told me about that. I was ready to start pulling out the fuel injectors