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Discussion Starter · #1 ·
Ihave a souped up 302 with gt40 heads port and polished.I went to a holly 670 truck avenger.When I tried to start it ,I had to advance the distributor so much that it ildes at about 3000 rpms.If i turn the distributor back down when running it won't rev up or it just dies.Also when I rev it up it will pop back out the carb but seems to run good.Is it my timing or carb or both?
 

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Sounds like you might have a really bad vacuum leak.Check around the base gasket for leaks and make sure all the ports are plugged on the carb and intake.
 

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Is the carb new? Can you reinstall the old carb to see if the problem goes away? That would be your best course of action for the moment.

You shouldn't need substantial amounts of timing to make it idle. Set it at maybe 12 degrees and then try to determine the real problem. Are you checking timing with the light connected to #1? (the front passenger side plug wire)

to test for vacuum leaks: Get a can of carb cleaner and install the straw attachment. Direct the spray toward the baseplate (all around it) and any other items of concern, such as the intake manifold gaskets. If the RPM increases greatly, you have probably found a leak.

Hoses can be checked by pinching them shut with a pair of needle nose. Otherwise it is all visual and may require removing the carb for a gasket inspection.

_________________
Dennis

65' Stang

393 Stroker, Toploader 4 spd, 9" 3:70 rear.

Victor Jr. Knockoff Heads, 282S cam, Stealth Intake, Bigs Stage 5 750DP, Accufab Headers, Scattershield, Caltracs.



<font size=-1>[ This Message was edited by: dennis111 on 6/17/06 7:28pm ]</font>
 

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use some carb cleaner and spray the base of the intake, if the idles increases you found your leak
 

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Discussion Starter · #8 ·
Well I tried the cleaner and no change in idle.It still has the high idle and backfires when u rev it up.Could one of my roller rockers be to tight and be holding a intake valve open?Would thismake it ilde to high,I know it could cause the backfire .
 

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On 2006-06-19 03:55, V8RANGER wrote:
I had efi(Megasqurit) on it and that backfired to.But it run good and idle good.

I'd say exchange the carb you got or borrow another carb and try it.

Not sure if your old efi had its own manifold--perhaps the manifold gaskets are leaking--they can leak in the block valley and you wouldn't be able to detect it.

Backfired before? Sounds like it is time for a leakdown test. How is your distributor points plate? (assuming you are running a stock points distributor)
 

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Discussion Starter · #12 ·
I just got done with a compression test and my #2 cylinder has no compression.the lifers go up and down and seal.the piston looks real wet.Is this a blown head gasket?
 
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