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hesitation very intermittent.
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Author:  slantsixbob [ Wed Feb 17, 2010 6:19 pm ]
Post subject:  hesitation very intermittent.
carb is a 1920 holley. yes it is a reman, obviously this doesnt help but is not directly the issue as it has ran fine for a long time.


its not on launch its usually while driving. it does not happen all the time either. ill be driving along and it will be running fine and then when i hit the gas it goes then the rpm goes down like its going to die but it doesnt. i checked the filter and lines for clogs nothing. ive used a clear fuel filter for a few moments to see if there is any obvious foreign materials coming up and its all clear. any ideas? could the metering block just be telling me it wants to eat itself soon or is it just because the throttle shaft bushings could be old and worn out. :?
Author:  Aggressive Ted [ Wed Feb 17, 2010 8:38 pm ]
Post subject: 
This is a very common problem with the Holley 1920 especially when jetted a little on the lean side with a #55 or a #56 jet and having opened up the high speed idle bleed.

What jet are you running?

How quickly does the accelerator pump shot happen?
Are the linkages sloppy delaying the shot?
How long does the pump shot last when you gently push down?
or does it engage at all?

Sounds like you have a delay.....it should be immediate and very strong.
You may have some blockage in the circuit.....you can take the small "E" string from a guitar and fish it though the outlet and through the economizer body. Sometimes there can be a little corrosion build up..and the fine wire will clear it. My first choice is to hard mono-filament to clear the holes. It is a little more flexible......

Yes, vacuum leaks can cause this too.........check the (3) small bolts on the top of the power valve. Make sure the gasket is good condition. It may not be activating quickly enough.....creating a delay in the response. Sometimes they will loosen over time.

A good rebuild wouldn't hurt. Good gaskets really help. Make sure the economizer bolts are snug...........you don't want it leaking around the accelerator pump and loosing pressure which effects the pump shot volume.
Author:  THOR [ Wed Feb 17, 2010 9:40 pm ]
Post subject: 
This is an issue that just started. His pump shot is proper and his car has a #57 jet in it. I went over and looked at it.

It seems that his main issue is the fact that it is reman. Regardless, up until now it has run very well. The fix?

Remove air cleaner and hold down topper from carb, rev engine up, choke engine completely with hand while holding carb open. Remove hand and rev engine until stable, and repeat a few times.

Problem gone, for now at least. I think a chunk of crap came loose from somewhere and was plugging the metering block some.

We shall see.....

:mrgreen:

~THOR~
Author:  hellion_locdogg [ Wed Feb 17, 2010 11:48 pm ]
Post subject: 
I run a #58 and my car runs great. It actually pings a little on 87.

Sorry for pirating your post.
Author:  slantsixbob [ Thu Feb 18, 2010 10:31 am ]
Post subject: 
no worries all input is useful :) so far so good. ill update if i have any other issues. seems to be leaning towards the main circut was getting a little clogged. runs good again.
Author:  Aggressive Ted [ Thu Feb 18, 2010 11:14 am ]
Post subject: 
Bob,

Be sure to run a very good filter. Some of the common filters out there still pass allot of small debris. The Perma-Cool canister fuel water separator filter that I am using filters down to 2 microns. Since installing it 2 years ago I have had no further problems.
Author:  slantsixbob [ Thu Feb 18, 2010 1:07 pm ]
Post subject: 
got a part # ? id be willing to give it a try i use the standard aluminum/steel ones.
Author:  Aggressive Ted [ Thu Feb 18, 2010 7:52 pm ]
Post subject: 
Perma-Cool 81794 - Perma-Cool Fuel Filter and Water Separator Kits

Click on the red link by name to view pictures of install. Did SL6 Dan's fuel line upgrade with 30R9 hose.....not more melted fuel lines. I installed a Summit fuel pressure gauge since the photos were taken.
Author:  slantsixbob [ Thu Feb 18, 2010 10:37 pm ]
Post subject: 
alright thanks. ill do some looking around tomorrow. its gettin late for me.
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