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Old 05-08-2010, 09:10 PM   #1
aggieguy713
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Possible timing issue?

Just recently replaced my cap and rotor buttonwith an accel super coil. For about the past week when I get into fourth or fifth gear and get on it, it backfires through the carb and then it will cut out and die. Just yesterday, I had to call a buddy of mine to pull me home because it was acting like it was flooding out and j couldn't get it to stay running. Not sure if this is a timing issue or a carb adjustment, thanks.
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Old 05-08-2010, 09:17 PM   #2
LandonL
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Re: Possible timing issue?

Does the truck not even want to start? If it has a hard time starting you may've loosened the nut holding the distributor down. If you can twist the distributor freely right now, all you need to do is tighten the bolt. Happened to me but I had to push it home haha.
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Last edited by LandonL; 05-08-2010 at 09:17 PM.
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Old 05-08-2010, 09:20 PM   #3
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Re: Possible timing issue?

It starts, hut acts like it's not getting enough gas or the timing is too retarted. No the bolt is there. We had a friend of mine get the timing pretty close not sure what to do at this point.
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Old 05-09-2010, 11:10 AM   #4
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Re: Possible timing issue?

Is it not getting enough gas?
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Old 05-09-2010, 11:29 AM   #5
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Re: Possible timing issue?

i'd recheck what you did// like the sparkplug wires and make sure they r wired right going to the proper cylinders
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Old 05-09-2010, 12:13 PM   #6
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Re: Possible timing issue?

Quote:
Originally Posted by cdowns View Post
i'd recheck what you did// like the sparkplug wires and make sure they r wired right going to the proper cylinders
EXACTLY... IF IT WAS RUNNING GOOD B-4 YOU DID THIS, & NOW IT'S NOT... WELL I'M NOT A BIG BELIEVER IN COINCIDENCES. (MORE THAN LIKELY SOMETHING YOU DID OR DIDN'T DO) JOHN
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Old 05-10-2010, 09:14 PM   #7
aggieguy713
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Re: Possible timing issue?

All the sparkplug wires are right, the timing is as close as i can get it without having a timing light. It was backfiring before the change, just got progressively worse (maybe a coincidence). Question is now...how do i begin to tune the carb?
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Old 05-11-2010, 08:12 AM   #8
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Re: Possible timing issue?

usually when it backfires thru carb its too lean, not enough fuel. i would check fuel filter, then fuel pump
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Old 05-11-2010, 09:01 AM   #9
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Re: Possible timing issue?

It is possible for the timing to do this but if it starts okay after sitting a while and then acts up, something else is causing you problem.

I'd look inside the carb throat with a flashlight immediately when it acts see if you can smell or see fuel dripping into manifold. If you have a quadrajet, they're known to have leaking problems and need to be epoxied.

Don't overlook the possibility of bad valves. Escaping hot gasses will prematurely ignite fuel in the intake and cause it to backfire up the carb.

My vote goes for the overly rich/flooding condition, though.
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Old 05-11-2010, 10:34 AM   #10
norske
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Re: Possible timing issue?

Had this happen to me and the pickup coil in the distributor was bad. Checked it with an ohm meter, it read 900 ohms, should've been open.
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Old 05-11-2010, 04:26 PM   #11
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Re: Possible timing issue?

You need to time it with a light if at all possible. If it's too retarded or advanced, yes, it will cause backfiring, especially if there is also some carb tuning needed. How did you time it without a light?

To answer your carb question, basic carb tuning probably isn't going to help with the problem you're having - full throttle acceleration at low rpm/heavy load (I assume this is what you mean - get into 4th or 5th gear, step on it...). Generally, if you're having problems immediately upon dropping your foot, it's in the accelerator pump system: cam, lever, pump diagram, pump nozzle. If it runs ok if you feather the throttle a little, maybe it is running lean at heavy loads...in this case, maybe your secondaries are opening too early? What type of carb? Is the backfiring at a specific rpm? Maybe since you changed your coil to a stronger coil, there are other things in the ignition system to look at? Wires, plugs, plug gaps...
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Old 05-12-2010, 07:02 AM   #12
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Re: Possible timing issue?

First what kind of dizzy and other addons do you have?
My first thought would be the mechanical weights have rusted and stuck open when you timed it first then loosened up after running now your timing is way off.
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