Author Topic: Not running right  (Read 2324 times)

Offline Vol

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Not running right
« on: April 23, 2016, 07:40:42 AM »
I am trying to rule out issues I am having with my 455 and a Cliff Quad. I have my timing set at 12 degrees BTDC. I can start the engine and it idles at 800 rpm. When I try to bring up the throttle it dies. If I catch it I can get up to 3000 rpm. But once I back it down below 3000 rpm it dies again. The carb sat for quite a few years before I put it into service. Thoughts?

Offline Cliff Ruggles

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Re: Not running right
« Reply #1 on: April 25, 2016, 01:30:23 AM »
What is the carburetor number and application?

Offline Vol

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Re: Not running right
« Reply #2 on: April 25, 2016, 07:16:50 PM »
17059233 2578B7A. Cliff I had you build this carb a number of years ago for use on a 60 over 455 with crower cam 60916, stock crank and 72 stock 4 barrel intake, 6X heads, DUI HEI, and 4 tube headers. It was going to go in 59 Catalina. You probably built the carb around 2008-2009 timeframe. It has sat until a month ago when I dropped this engine in a 68 GTO chassis. I have it setup to break in the engine in the chassis only. So this is why I am asking about the carb setup to rule out issues i am having it run for break in.

In the process of getting this engine to run it has backfired through the carb—which can cause issues from what I read. I have not touched the carb other than bolting it down. and hooking up the fuel line and blocking all the vacuum ports.

I am not overly carb knowledgeable so seeking this boards help to rule out or troubleshoot. Thanks.

Offline Cliff Ruggles

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Re: Not running right
« Reply #3 on: April 26, 2016, 03:18:48 AM »
Backfiring up thru the carb is probably not a carburetor problem.  That is usually an ignition, timing, or valves set too tight, sticking valve, etc.......Cliff

Offline Vol

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Re: Not running right
« Reply #4 on: April 26, 2016, 08:16:01 AM »
I have since got the timing down so the engine idles and does not backfire. Any ideas on what to check with my symptoms of running well at idle or at 3000 rpm but cannot or does not run in between?

Offline Cliff Ruggles

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Re: Not running right
« Reply #5 on: April 27, 2016, 03:19:59 AM »
Not sure, can't say I've symptoms like that.

If you think the carb is an issue you can send it here and we can run it on our test engine.....Cliff

Offline 429bbf

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Re: Not running right
« Reply #6 on: May 05, 2016, 08:52:06 PM »
it sounds like the metering rods are stuck down. stick a pencil or straw down in there and crack the throttle see if there lifting up.keep your face back incase it backfires.hth