Engine stumbling/flat on acceleration
Thread Starter
Drifting
Joined: Feb 1999
Posts: 1,481
Likes: 1
From: San Diego CA
Engine stumbling/flat on acceleration
I had my '99 Coupe parked for three weeks and I just started driving it again. I first noticed the engine stumbling a few times when starting from a stop. Today it did it again so I experimented a bit. It stumbles slightly from idle if you jab the throttle. It also stumbles and feels obviously flat on hard acceleration at speed.
I took a look around and everything seems to be in order (the intake isn't loose or any other common problems). The idle is smooth and constant. I did have it off the battery so the computer probably reset. Maybe it's going through it's learning process?
Anyone have any thoughts?
Thanks!
Mike
I took a look around and everything seems to be in order (the intake isn't loose or any other common problems). The idle is smooth and constant. I did have it off the battery so the computer probably reset. Maybe it's going through it's learning process?
Anyone have any thoughts?
Thanks!
Mike
Thread Starter
Drifting
Joined: Feb 1999
Posts: 1,481
Likes: 1
From: San Diego CA
No critters. I just had the time to run out and check the codes. I see a PCM code of P1111 (intake temperature sensor intermittent high voltage) which could explain it. However, it was a history code so it dosen't seem like a current issue.
Mike
Mike
Last edited by Mike Schriber; Feb 6, 2006 at 06:54 PM.
Melting Slicks
Joined: Mar 1999
Posts: 3,326
Likes: 0
From: Taylor TX
NCM Sinkhole Donor
I had similar symptoms a while back - it was misfire. I had no misfire codes, it had to be monitored while running.
The cause ended up being a fouled fuel injector. After it was cleaned out, I replaced the fuel filter and everything has been fine.
The cause ended up being a fouled fuel injector. After it was cleaned out, I replaced the fuel filter and everything has been fine.
Thread Starter
Drifting
Joined: Feb 1999
Posts: 1,481
Likes: 1
From: San Diego CA
It didn't feel like a misfire but I'll do some research. It only sat for three weeks... I've had it parked for much longer before without issues.
I've been meaning to replace the plugs anyway so I'll get off my rear and do it. I already have a set of the new pre-gapped GM iridium plugs sitting in my garage. My NGK coppers should still be good but I did a lot of racing on them so I decided to switch (it's a street car only now).
Any recomendations as to fuel system maintenance? Is there an additive (something I usualy avoid) that works well in Corvettes for cleaning the injectors and such?
Thanks for all the info!
Mike
I've been meaning to replace the plugs anyway so I'll get off my rear and do it. I already have a set of the new pre-gapped GM iridium plugs sitting in my garage. My NGK coppers should still be good but I did a lot of racing on them so I decided to switch (it's a street car only now).
Any recomendations as to fuel system maintenance? Is there an additive (something I usualy avoid) that works well in Corvettes for cleaning the injectors and such?
Thanks for all the info!
Mike
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