AFM and idle mixture adjustment screws
#1
AFM and idle mixture adjustment screws
All things being correct, and they never are, is there a preset procedure for these adjustment screws?
Currently, the AFM adjustment is about 3 turns out, but makes no difference where I put it. The idle adjust is bottomed out to achieve a very rocky 700-850 RPM in drive.
All the vacuum lines that I could check are OK. I'm just looking to find an adjustment to leave these screws at while checking other things.
Thanks, Jim
Currently, the AFM adjustment is about 3 turns out, but makes no difference where I put it. The idle adjust is bottomed out to achieve a very rocky 700-850 RPM in drive.
All the vacuum lines that I could check are OK. I'm just looking to find an adjustment to leave these screws at while checking other things.
Thanks, Jim
#2
Join Date: Mar 2008
Location: Pacific Northwest USA
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The AFM adjustment is typically about 2 turns from the bottom. I'm not aware of a typical or base setting for the idle speed adjustment screw.
Both adjustments are 'air' adjustments....more or less air allowed to enter. In either case ....most likely the idle speed....the passageways might be clogged...rendering the adjustment ineffective. The idle speed screw is in the 'air distribution block' can be removed and de-gunked.
Or.....you have air coming in from somewhere else that is masking the adjustments.
Is the throttle blade set to the proper .002" gap? And the throttle bore clean?
Cheers
DD
Both adjustments are 'air' adjustments....more or less air allowed to enter. In either case ....most likely the idle speed....the passageways might be clogged...rendering the adjustment ineffective. The idle speed screw is in the 'air distribution block' can be removed and de-gunked.
Or.....you have air coming in from somewhere else that is masking the adjustments.
Is the throttle blade set to the proper .002" gap? And the throttle bore clean?
Cheers
DD
#4
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Location: Pacific Northwest USA
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#5
The throttle blade is set to the .002" gap and the throttle bore is clean.
Air is probably getting in somewhere else. I haven't checked everywhere but most of the engine compartment vac is secure. Smog stuff is gone.
I added a large Fram fuel filter prior to the pump but I assume the residual rust powder in the system that's still working it's way through could be an idle problem also.
I appreciate the input.
Jim
Air is probably getting in somewhere else. I haven't checked everywhere but most of the engine compartment vac is secure. Smog stuff is gone.
I added a large Fram fuel filter prior to the pump but I assume the residual rust powder in the system that's still working it's way through could be an idle problem also.
I appreciate the input.
Jim
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