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Unread 09-10-2012, 08:04 PM   #1
Alex77cj7
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1977 CJ7 
 
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missfiring when cold?

So recently my 77 cj7 304 has started misfiring when first started and running really rough for the first 15-20 minutes of driving. When i first start it, it misfires really really bad and if i rev up the engine for a minute or two it stops.

Has anyone had this problem before? What causes it? It wasn't doing it before I readjusted my timing.. Could I have cracked the prestolite distributor?

Any and every bit of help is greatly appreciated.

Thanks,
Alex.

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Unread 09-10-2012, 08:07 PM   #2
Alex77cj7
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Also seems to be taking longer to start in certain circumstances. It also still backfires under load. I was going to do the team rush upgrade soon. Do yall think that that would help?
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Unread 09-11-2012, 12:47 AM   #3
row684
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Sounds like your choke to me, check to make sure the wire is still hooked up to it and getting power
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Unread 09-11-2012, 03:33 AM   #4
RWise
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yep, check the choke!
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Unread 09-11-2012, 06:11 AM   #5
Alex77cj7
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I've checked my choke plenty of times. I'm running a brand new holley truck avenger 600. The choke closes all of the way and stays choked long enough for my engine to warm up.
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Unread 09-11-2012, 09:08 AM   #6
Centerfire
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I don't think the choke is suppose to close ALL the way.
Some air needs to go into the carb for the proper mix.
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Unread 09-11-2012, 10:09 AM   #7
Alex77cj7
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Quote:
Originally Posted by Centerfire
I don't think the choke is suppose to close ALL the way.
Some air needs to go into the carb for the proper mix.
Oh I thought it was supposed to fully seal! Okay so should I try backing it off till its open a little?
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Unread 09-11-2012, 10:11 AM   #8
Centerfire
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Just a little.
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Unread 09-12-2012, 03:47 AM   #9
RWise
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This time of year in the swamps, about 1/3 open, I set mine in cold weather,,,,,
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Unread 09-12-2012, 04:33 AM   #10
Hawk4097
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When cold the choke being closed is the right position but should quickly start to open up. When you put the carb on did you adjust the adjustment screws? make sure how ever many times you turn one side you turn the other the same. That can cause backfiring. You may want to bust out the timing light as well and ensure that your timing is correct. Also to rule it out do a spark check on all cylinders.
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Unread 09-12-2012, 09:52 AM   #11
Alex77cj7
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Quote:
Originally Posted by Hawk4097
When cold the choke being closed is the right position but should quickly start to open up. When you put the carb on did you adjust the adjustment screws? make sure how ever many times you turn one side you turn the other the same. That can cause backfiring. You may want to bust out the timing light as well and ensure that your timing is correct. Also to rule it out do a spark check on all cylinders.
That's how my choke works now! When I put the carb on it ran perfect! Just had to adjust the idle speed. Then after a week or two I had to tune it using the mix screws. I also set the timing the same day. All my plugs and wires are brand new accels. And it stops missing after I rev it up! But when I rev it up to make it stop it blows white smoke!
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