cold blooded
Thread Starter
Drifting
Joined: Apr 2001
Posts: 1,924
Likes: 275
From: Portugal
cold blooded
I've got a '90 with a 427; speed density. I could go on but I'm looking for more basic problems. It's developed a significant "stumble" when cold. I've gone to a 3-wire O2 (long ago) and checked the fuse and it's not blown. No vacuum leaks. What else? My short list includes looking at the wires to the O2 and even pulling the plug off it and keying the ignition and confirming it's getting power, checking the plugs for fouling, checking for condensation in the vacuum lines to MAP and fuel regulator. Any other ideas? 
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,008
From: Texas
Originally Posted by DiabolicalDave
I've got a '90 with a 427; speed density. I could go on but I'm looking for more basic problems. It's developed a significant "stumble" when cold. I've gone to a 3-wire O2 (long ago) and checked the fuse and it's not blown. No vacuum leaks. What else? My short list includes looking at the wires to the O2 and even pulling the plug off it and keying the ignition and confirming it's getting power, checking the plugs for fouling, checking for condensation in the vacuum lines to MAP and fuel regulator. Any other ideas?
Thread Starter
Drifting
Joined: Apr 2001
Posts: 1,924
Likes: 275
From: Portugal
Coolant temp sensor isn't it - I have a scanner and the coolant temp looks right.
Stretched timing chain is highly unlikely - only about 1000 miles on the engine.
What does the IAC do? I'm not real familiar with it's operation. If it was screwed up I guess that could do this but it wouldn't make sense for it to only do it when cold, right?
Stretched timing chain is highly unlikely - only about 1000 miles on the engine.
What does the IAC do? I'm not real familiar with it's operation. If it was screwed up I guess that could do this but it wouldn't make sense for it to only do it when cold, right?
