Idle Question on V8 swap -
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Unread 07-31-2002, 04:18 AM   #1
highway jeeper
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Join Date: Jan 2002
Location: Lisbon, CT
Posts: 34
Idle Question on V8 swap

I have an 87 YJ automatic, and I just completed a 305 install with dual exhaust. The truck has a model 1850 Holley carb and I am having idle problems now that the exhaust is on.

There is a huge loss in rpm when I shift from park to drive and the engine practically wants to die. My tach gage is off since it is setup for a 6 cyl, but I say I am at around 1100 rpm at idle in park, and when I shift into drive I bet I am only at 200 rpm.

The weird thing is that I drove it to the muffler shop with a temporary exhaust Friday night and I did not have this problem. It only came after the complete exhaust was on.

The float level on the Holley is fine. The air fuel screws are at the bottomed out position with a 1 1/2 revolution turn from bottom (I just positioned them there as a starting point). I double checked the hoses (all new) but do not see any leaks.

Anyone have any idea why it is changing rpm so much? It runs great on the road - love the new power.


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Unread 07-31-2002, 01:26 PM   #2
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1988 YJ Wrangler 
Join Date: Nov 2000
Location: Calgary, AB
Posts: 6,879
The only thing that I can think of (without standing beside your beastie) is that there is might be some backpressure in the exhaust system that is causing your grief .. take it back to the muffler shop and have them check it over.

Another thing is the size of the pipes used .. do you have a Y or H pipe happening, or are you running complete dual with no cross-over? I am using dual exhaust with no cross over, and have no lack of power (for now )
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