I have a 1992 Buick Lesabre with 135,000 miles. It has the bulletproof 3.8 3800 engine. The engine runs well when first started. It continues to run well for about 30 minutes. Then it will begin to cut out under acceleration. It will continue to worsen the longer you drive it. You have about 1 inch of pedal travel where it runs okay. You can floor the gas, and it will cut up so much it's almost as if it has died, but doesn't. It doesn't smoke and only backfires occasionally when under hard acceleration. It comes right back to idle with no stumbling or anything else.
It idles fine incidentally all the time and will not die even when it runs like this. It's just under acceleration when it's been driven for some time.
This is what gets me: It will continue this behavior until you cut the engine off and immediately restart it, at which point then it will run fine for a couple of minutes and then begin cutting out again. Interestingly enough, you can let it idle for more than 10 minutes from a good start even when the engine is warm, and it will not do this. Take off down the road and it starts again. The longer you drive it, the shorter the periods it runs okay decrease.
The car will run well again once you let it sit for a while (20-30 minutes). I have already replaced the coil packs btw. I was replacing some stuff on the car in the dash, and I had the battery disconnected for two weeks in the garage. No SES light before or now.
Fuel pump overheating and trying to shut down?
Bad plug wires?
Burnt wire on engine harness? Grounding somewhere?
Bad O2 sensor? (Should have SES light?)
Any help is greatly appreciated. This is normally a great running car, and I really need it to work in it. It has that great GM paint.I think you know what I mean.
I have a 94 lesabre and what u have descibed it right to a
t of what my car does. I'm talking exactly. And I thought the same thing about the computer. Mine went bad. So I replaced it. Still does it. No smoke good gas mileage. I maintane my car perfect. New plugs, wires, coils and module, fuel filter, I have know clue. I thought the same thing. About the fuel pump. I have not replaced mine yet. But I notice that the warm it is out side the worse it acts up. Cause last night it was like 20 out and I drove it like 60 m. Non stop and it would only act up when I hammered on it. It run great, idles good. My cat. Is clear and my o2 sensor is brand new.. I thought maybe coolant temp sensor. Or mas- ari flow. But I have no codes. If you figure this out let me know. Cause it has 150000 m. On it and it is still a good car. I will change the fuel pump and let you know if that work. I'll be glad to help and awnser any other question.
March, 30, 2007 AT 6:54 AM
I had a very similar problem with my Century. I know it's not the same car you two are talking about but the problem I had was with the fuel injector. One was bad and it kept shorting out the computer, causing the car to stall. Might be worth just checking out.
March, 31, 2007 AT 11:55 PM
I took my buick for a long drive last night to see exactly how long it will run before it screws up. After a hour and a hlf I hit inerstate. I still can't put it to the floor but I ran it up to 105 for like 10 m. And it didn't miss a beat. But the out side temp. Was about 40. Degrees. So I got to thinking that maybe it is the mass airflow sensor. Cause the minute I get past half throttle it messes up. So if you have a junk yard near you see if they have a mass air flow sens. Cause it will be cheaper than a anew one. I'm gonna try it. I don't think its a fuel pump problem. The coolant temp. Sensor is like $ 20. And if it goes it messes with the fuel injection. I'm gonna replace it to and let you know. Just figured id pass on the info
April, 4, 2007 AT 11:19 PM
Hey thanks for the reply. The ambient temperature was a lot less today than it was the other dayand tonight when I was driving it, I couldn't get it to act up whatsoever. I was thinking it definately had something to do with outside temp. I think you might be right about the MAF sensor. Let me know if that's what makes yours act up. I won't have time to do anything until monday or later with mine. I was thinking that today when I was driving it around.
April, 5, 2007 AT 9:48 AM
Hey. I might have been wrong. I drove it the other day it was like 75 out and it wouldn't go far before messing up. So I started disconnecting sensors. Everyone I disconnected threw an engine soon light. Including maf sensor. And coolant temp. When I plugged them back in and restarted it. The light went out. I did it one by one. So. All the sensors. Are working. But there was no change in how bad it acted up. It's not the egr or the tps, or aic. It's not the fuel pump. When you start you car in the morning open the hood listen for air hissing. It will sound like a vacuum leak. If you rev it up real quick. Just flick the throttle cable just enough. Don't hold it in just push and let go. Listen around the fuel rail for the sucking sound. It may be quiet or a bit loud. Its your intake manifold gasket. That is why the outside temp effects it. It's pulling hot air in to the intake. It is not being picked up by the computer cause no sensors detect that. It just through them alittle off.. I am going to replace mine this weekend. And let you know how hard it is. They only cost $30. It make total sense now. I'll let you know how it goes. If it's something you need help with I'll be glad to give you a walk through.
April, 6, 2007 AT 12:46 AM
Before you do that, get you a spray bottle of water and spray it around the area you suspect it's leaking and see if it cuts out. I drove it to school 20 miles today without any issue whatsoever. I then drove it to work without any problems. I deliver food by the way, so I drove it for 5+ hours. It ran perfect. The temperature never got over about 55 today.
Let me know what happens with yours. I am going to try to to clean the MAF first before I tear anything down. On the plus side for you, that should be a fairly straightforward job since everything is in easy reach and it's a 90 degree v6, so the pushrods won't have to be removed so you won't have to mess with resetting the valves like on a 60 degree (2.8L).
Thanks for you help. I'll wait for your reply
April, 23, 2007 AT 12:49 PM
Well I just replaced the gasket and clean everything! The injectors and throttle body too. No dice. It's 75 out.(I live in central penns.) And as soon as I got on the road and punched it it acted up right away. But once it shifts it goes good till the rpm's climb up and then it start cutting out. Well as much as I hate it i'm gonna spend $50 bucks and have the chevy grage tell me what's wrong. So as soon as I know you'll know. I
m out of f.G ideas! May be the fuel pump or coils or something else. But still no code. Well later
April, 24, 2007 AT 2:49 AM
Kyle, I haven't had a problem since the other day. It goit up to about 75 today and still no issues. I expect it to come back as soon as the temp increases a bit (AL). I did notice a while back that the intake hose had slipped off right in front of the MAF honeycomb. I think it may be just dirty. I couldn't find a single one at the local PAP incidentaly. They were all missing. Every last one. I mean Lesabre, Park av, Bonneville, Delta. Every clone.
I replaced my coils, and I will say although it didn't fix the problem, the car ran noticebly better throught the rpm range, so it's a good investment. I'll be in touch. Thanks for the help.
May, 8, 2007 AT 3:22 PM
Hey, did you get it fixed? I just started to have problems again. Now once it starts, cutting it off and restarting has no effect. Once it stops, it stops. Temp does seem to be a factor.
Let me know
May, 10, 2007 AT 6:57 AM
I having same problem the car will run fine at first start up but once it get hot it dies out wait like 5 to 7 mins. And it starts back up. I change ignition coil, ignition module and fuel pump still having same problem. If theres anyone who this has happen to please let me know how you fixed it. Bishopotis@yahoo. Com I've been hearing a crank sensor but really tired of guessing. Need a response soon.