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Old 10-11-2010, 10:37 PM   #1
aztecworrior
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carburetor or distributer?

i have a question regarding my jimmy.. its been acting funny lately. im really confused with the driving characteristics lately.. used to run fine but i had to replace some parts, (edelbrock carb, and distributer internals.)
it will drive fine, then come in and out of power.. (rpms will go up.. down...up... down...) almost sounds like the truck is misfiring.. the only difference is it will only do it iff i blip the throttle while driving around.. very weird.. let me know if you have any ideas.. i thought because it came in and out of power if might be spark.. but, your the experts! thanks!
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Old 10-11-2010, 10:40 PM   #2
red71cheyenne
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Re: carburetor or distributer?

Dizzy internals? Did you replace the module? Or have it out and not replace the heat sink goo? Almost sounds like you are having heat issues with the module.
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Old 10-11-2010, 10:50 PM   #3
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Re: carburetor or distributer?

I have been fighting weird things like this for over a year. New carb, new coil, cap, rotor, plugs, wires etc. Never seemed to fix the issue. Each of those things were overdue but they didn't fix the intermittent power flux I had. Sometimes it ran pretty well, then without explanation it would be a dog even during the same drive. My buddies thought I was nuts, every time I tried to show them it of course was having one of it's good days (either that or I got the "it's a 350 and a heavy truck of course it's a dog"). Anyway...

I put in a new MSD dizzy on Sunday. It's like a new truck. Seriously i should have just bought a new one a year ago. It's smoother and has more power in my basically stock 350 than I have ever had since owning the rig.
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Old 10-11-2010, 11:12 PM   #4
aztecworrior
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Re: carburetor or distributer?

so what msd setup did you go with? photos? price?
by the way, big fan of your truck... those pics of it in alaska are just amazing!
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Old 10-11-2010, 11:13 PM   #5
red71cheyenne
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Re: carburetor or distributer?

Quote:
Originally Posted by AlaskaMatt View Post
I have been fighting weird things like this for over a year. New carb, new coil, cap, rotor, plugs, wires etc. Never seemed to fix the issue. Each of those things were overdue but they didn't fix the intermittent power flux I had. Sometimes it ran pretty well, then without explanation it would be a dog even during the same drive. My buddies thought I was nuts, every time I tried to show them it of course was having one of it's good days (either that or I got the "it's a 350 and a heavy truck of course it's a dog"). Anyway...

I put in a new MSD dizzy on Sunday. It's like a new truck. Seriously i should have just bought a new one a year ago. It's smoother and has more power in my basically stock 350 than I have ever had since owning the rig.
Can't say the same thing here, but I did just put in a new Skip White dizzy and so far its working well. My engine is new, so I'm just getting a feel for how it is.
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Old 10-12-2010, 01:12 AM   #6
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Re: carburetor or distributer?

Quote:
Originally Posted by aztecworrior View Post
so what msd setup did you go with? photos? price?
by the way, big fan of your truck... those pics of it in alaska are just amazing!
The streetfire, I would have to look up the exact model. It was about 180, but can be had for 150 or so from summit. Summit hammers us on the shipping up here so 180 at the local Napa seemed just fine. I don't have any photos of mine but here is a link to what I bought.

http://www.msdignition.com/Products/...stributor.aspx

Thanks for the comments on the rig!
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Old 10-12-2010, 06:53 AM   #7
chuckmc8
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Re: carburetor or distributer?

I had a similar issue with the Edelbrock carb on my 67. It would misfire on oppoiste sides of the engine- I finally traced it back to the carb has a passage to get fuel from one side of the carb to the other and it was stopped up in the middle-it nearly drove me crazy. With my Weiand manifold, one side of the carb does 4 cyls and the other side does the other 4, but i had to look at how the runners on the intake went to which cylinders, and when I did, I realized that the cylinders that were misfiring were all fed by that one side of the carb. It would run fine for about 1/4 mile ( then would use up the gas that had made it through the nearly clogged port in the top of the carb) and then those 4 cyls would run out of fuel. Take the carb top off and remove the needle seats and spray carb cleaner thru the passage from where the fuel comes in and make sure it flows into both fuel bowls.....worked for me! PS, I thought it was a misfire and bought a new HEI dizzy and installed it to eliminate that from troubleshooting. when that didn't solve the prob, I finally found that clogged fuel port. Sorry for the long reply. Hope this helps!
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Old 10-12-2010, 07:54 AM   #8
hgs_notes
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Re: carburetor or distributer?

Might be the fuel filter. I had a rusty gas tank and it kept clogging the filter. It acted a lot like that.
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Old 10-12-2010, 08:21 AM   #9
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Re: carburetor or distributer?

if they are high mileage check compression I have 2 blazers and both had those issues. Ran good just not great. Change carbs dizzys etc. 7 cylinders great 1 on its way down. put top ends in both motors
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