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Jun 11, 2005 | 11:01 PM

john1977

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From: zanesville ohio

surging

Just returned from a show and on the way home I noticed at low speeds 40 and under that I could hear more than I could feel like it was surging under load. Where I noticed it the most was like going up a grade or hill and when I would give it more gas it was not real responsive. Does this sound carb related like to rich,to lean?

Jun 11, 2005 | 11:42 PM

SkunkApe

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From: I KNOW JESUS... HE'S MY GARDENER

Vacuum issue? Clogged catalytic converter?

Just a guess...

Jun 12, 2005 | 12:05 AM

BigBlockk

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From: North Bend Ohio

Surging is a lean condition. Your part throttle cruise metering is a touch lean. One step smaller primary metering rod should cure this. You'll probably get better gas mileage to.

You could also try one step stronger power piston spring with the original rods. This will get the rods up out of the jets a little more under cruise vacuum.

BigBlockk

Later.....

Jun 12, 2005 | 01:35 AM

Aflac

Race Director

Joined: Oct 2002

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From: Smalltownville Michigan

Cruise-In 5, 6 & 10 Veteran

St. Jude Donor '09

while your'e at it, check the fuel lines at the pump... the rubber ones could be pinching off...when mine did that, i thought I had carb issues... changed the hoses out for new molded lines and it went away...

Jun 12, 2005 | 04:32 PM

john1977

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From: zanesville ohio

Would this also cause it to surge at idle in neutral? You can hear it and when I hooked up a vaccum guage you can see the needle fluctuate? Anyone have an idea what I should be looking for or how to go about finding my problem?

Jun 12, 2005 | 11:58 PM

BigBlockk

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From: North Bend Ohio

Quote:

Originally Posted by john1977

First of all, what kind of carburetor do you have? My earlier comments were for the Q-jet. You need to get some carburetor cleaner down in there. Make sure the idle air bleeds are clean. A paper clip works good here. With the engine off turn the idle mixture screws in until they gently seat. Count and record the turns for future reference. Now, back them back out to where they were before and add 1/2 turn. If the idle increases and smooths out you know you're on the right track.

This would be a good time to check the ignition timing. Retarded timing will make the idle rough. If you have a timing light set the advance somewhere around 12 to 16 BTDC.

BigBlockk

Later.....

Jun 13, 2005 | 08:28 PM

john1977

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From: zanesville ohio

BigBlockk; Sorry for the delay in replying,Yes it is a Q-jet and timing is at 12 deg. have been in the garage playing with it. I turned the idle scews in till they just touched and back them out 1 1/4 turn to start.It is not surging as bad but it will run for several seconds like 10to 15 sec.then you will hear it slow down a little then pick back up (100 rpms)

Jun 13, 2005 | 09:25 PM

BigBlockk

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From: North Bend Ohio

Quote:

Originally Posted by john1977

Bring the timing up to about 16 degrees. The idle speed should increase. Reset it with the idle speed screw on the carburetor. Set the idle mixture screws to about 2 1/2 to 3 turns and see how it sounds. These changes may cure the part throttle cruising surge it has also.

BigBlockk

Later.....