Running problem Help!
Thread Starter
Pro
Joined: Jul 2002
Posts: 588
Likes: 0
From: Da old Dominion va
Running problem Help!
Ok you gear heads figure this one out. I have a 1994 LT1 Automatic Corvette with 87,000 miles on her. When she is cold at start up she hesitates and stumbles at low RPM's even backfiring through the intake, and just basic poor driving. When the water temp reaches 170 the problem mostly goes away, but will still have an initial stumble from a light, Now the car has been doing this a couple years now no one has figured it out yet. the service engine soon light is not on. The plugs have about 20-25,000 on them the coil about the same. This is stuff done before the problem. Since it started I've replaced the Optispark (You were gonna say replace Optispark were'nt you?) fuel filter, plug wires. The air filter is clean. I would appreciate any and all the help Thank you. :flag
Racer
Joined: Jul 2001
Posts: 253
Likes: 0
Re: Running problem Help! (YellowYbody)
Just a thought and a 'bump' here.... In basic auto mechanics (back in 1975) I was taught that backfire through the air cleaner is too much advance on the timing, and backfire through the exhaust is too much retard on the timing.
Now, let's jump 20 years to your car. Computers and sensors and such, but has the timing been checked with the little wire disconnected?
Hope this helps or inspires someone else to pick it up from here.
BIll
Now, let's jump 20 years to your car. Computers and sensors and such, but has the timing been checked with the little wire disconnected?
Hope this helps or inspires someone else to pick it up from here.
BIll
Racer
Joined: Jul 2001
Posts: 253
Likes: 0
Re: Running problem Help! (YellowYbody)
There's a little brown wire on my '86 that must be disconnected to check your timing. It's got the typical GM clip that always breaks when you try yo pull the 2 ends apart. :smash: Look near the driver's side of the engine bay back by cylinder #7. Disconnect and then check that timing.
Hopefully, someone will pipe in about the '94.
[Modified by 86VetteBill, 6:17 PM 1/26/2004]
Hopefully, someone will pipe in about the '94.
[Modified by 86VetteBill, 6:17 PM 1/26/2004]
Safety Car
Joined: Feb 2002
Posts: 4,212
Likes: 10
From: Sun City West Az
Re: Running problem Help! (YellowYbody)
What little wire?
As I recall, your car runs (in open loop) on the info from the CTS , the IAC and the fuel tables in the PCM. Have you checked both those sensors to be sure they are operating ok?
[Modified by ittlfly, 4:24 PM 1/26/2004]
