Ideas? Stumbles cold. Perfect when hot except high idle.
07-16-2012, 09:50 PM
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Ideas? Stumbles cold. Perfect when hot except high idle.
1983 944 - I'll keep this simple.
Car sat in garage for 3 years. Put away running perfect. First time was hard to restart. Tapping injectors finally got it.
It now starts easy but... when cold it idles at 750rpm. If I add throttle it stumbles down to 500rpm. Only when I let up does it recover. It will continue with this while cold. I can drive away by adding throttle as it's recovering itself after stumble and the engine will accelerate but not powerfully.
Once it warms up it runs perfect except it idles at 1300rpm.
The following have been changed one at a time and engine retested. No changes have occurred.
Timing, balance belt, and rollers. (needed to be done)
Cap, rotor, plugs.
Fuel filter.
Fuel pump tested and checks out per Clark's and Haynes.
DME coolant temp sensor.
I guess I should focus on what sensors change when it warms up.
Any ideas? -Brian
Car sat in garage for 3 years. Put away running perfect. First time was hard to restart. Tapping injectors finally got it.
It now starts easy but... when cold it idles at 750rpm. If I add throttle it stumbles down to 500rpm. Only when I let up does it recover. It will continue with this while cold. I can drive away by adding throttle as it's recovering itself after stumble and the engine will accelerate but not powerfully.
Once it warms up it runs perfect except it idles at 1300rpm.
The following have been changed one at a time and engine retested. No changes have occurred.
Timing, balance belt, and rollers. (needed to be done)
Cap, rotor, plugs.
Fuel filter.
Fuel pump tested and checks out per Clark's and Haynes.
DME coolant temp sensor.
I guess I should focus on what sensors change when it warms up.
Any ideas? -Brian
07-16-2012, 10:05 PM
#2
I'd look for vacuum leaks I guess.
I think that would cause both rough cold idle (too lean for cold enrichment to work) and high idle (excess air).
I think that would cause both rough cold idle (too lean for cold enrichment to work) and high idle (excess air).
Last edited by gtroth; 07-16-2012 at 10:34 PM.
