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Old 12-16-2009, 05:05 AM   #1
bentleyjd
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in need of help!

i have a 70 Chevy c-10 that i traded my Harley for about 4 months ago, and with my work hours and a baby on the way i really haven't been able to get into it much! as i drive it to the store and back ill try to get on it and see what shes got, but when do this it spurts real hard. i swapped the carb out tonight and was hoping this would fix this issue. well... i was wrong! it still does this "spurt" when i go to punch it! also after i have babied it up to speed for a while and go to come to a stop it will just die out on me if i cant slide it up into neutral quick enough! what is the deal ? why is it doing this? some one suggested the timing was off?? would that be the issue??
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Old 12-16-2009, 05:24 AM   #2
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Re: in need of help!

I think we need a better description than spurts. Can you explain a bit more?

I guess it sounds funny when you get on it and doesn't make much power. Does it idle ok?

As a guess, try looking for blue sparks at night with the hood open by the plug wires and dist cap. Bad wires, cap, rotor, plugs. A tuneup may help.

Does it sneeze out the carb? Lean. Look for vacuum leaks.
Backfires from the exhaust? Timing?
Pull a few plugs and look at them.
Idle RPM varies? Maybe a clogged fuel filter or obstruction in the fuel system?

Just throwing a few things out there to be checked...
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Old 12-16-2009, 07:43 AM   #3
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Re: in need of help!

get a full tuneup
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Old 12-16-2009, 08:21 AM   #4
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Re: in need of help!

Tune-up time fer sher.I`m thinking you mean it sputters,falls on it`s face,like it`s starved for fuel.It also could be a failing fuel pump.Either way,unless you know it just had a tune-up,it`s a great place to start.

That`s plugs,wires,cap,rotor,and points.I assume you looked at the air filter.A real bad dirty filter can rob enough air to do what you said.It would have to be reeeeeaalll dirty.
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Last edited by special-K; 12-16-2009 at 08:27 AM.
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Old 12-16-2009, 09:18 AM   #5
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Re: in need of help!

i replaced the spark plugs and did a trans tune- up (filter and fluids) the wires looked good but im gonna change them. should have when i did the plugs! the carb is good we pulled it off my buddys 72 c-10! i also changed the fuel filter too. the sound sounds like it sneezes if that makes any sense! like if i was to line up on a straight road and punch it it would " sneeze" as soon as i hit the peddle to the floor. but,however if i baby it into the gas she will roll smoothly down the road
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Old 12-16-2009, 10:27 AM   #6
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Re: in need of help!

points gap or dwell is important part of tune up
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Old 12-16-2009, 10:32 AM   #7
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Re: in need of help!

what is the gaping on a 350? just checking?
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Old 12-16-2009, 11:54 AM   #8
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Re: in need of help!

It never hurts to put a good gasoline additive in the tank and see if that helps after doing the tune-up and filter change. Sea Foam is good or Lucas.

Their could be a problem with vacuum.

Look in the distributor and make sure every thing that is supposed to move is not froze up with rust.

Just a few ideas.

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Old 12-16-2009, 06:58 PM   #9
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Re: in need of help!

Might also check to see if the vacuum advance is working.It will make it act like the timing is off.
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Old 12-16-2009, 08:33 PM   #10
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Re: in need of help!

i think i might run down and get it timed to see if that helps. i put a new fuel filter on today and no change ! figured id start small and cheap! also when it "sneezes" there is a strong smell of gas afterward if that would help diagnose anything !
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Old 12-16-2009, 08:34 PM   #11
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Re: in need of help!

what is the gaping on the plugs for a 350?
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Old 12-16-2009, 08:52 PM   #12
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Re: in need of help!

Quote:
Originally Posted by bentleyjd View Post
what is the gaping on the plugs for a 350?
stock with points? .035"
HEI .045"
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Old 12-16-2009, 08:48 PM   #13
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Re: in need of help!

Also you might want to see if your tank is rusted and sending crap up to the carb, been there done that, new tank and lines, cleaned out the carb and it runs like a champ now.

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Old 12-17-2009, 07:09 AM   #14
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Re: in need of help!

this is possibly a stupid question but dont know so i'll ask! would it being bored 30 over change the gaping?
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Old 12-17-2009, 07:47 AM   #15
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Re: in need of help!

You can have the timing just right (at idle), clean gas, plugs gapped properly and all new wires and if the advance mechanism (vacuum or centrifigal) isn't working it will make 'em sneeze when you stomp the accelerator. If you have replaced points and condenser, etc, make sure the condenser is not screwed down in a position to interfere with the advance.

Last edited by Roland; 12-17-2009 at 07:48 AM. Reason: extra letter
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Old 12-18-2009, 03:34 AM   #16
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Re: in need of help!

My 69 does this when it sits in the rain for a day or two. I tried everything with no luck until one day I noticed the distributor cap was wet, I popped it off and it was full of water. I wiped it out, put it back on and it ran perfect.
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Old 12-18-2009, 07:33 AM   #17
bentleyjd
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Re: in need of help!

how did the water get in there? was it just moisture build up or... im scared to get to far into taking the distributor apart cause im afraid it wont make it back together right!! im gonna run it down the road today and try to get the timing looked at and ill have him check the distributor as well! thanks for the good leads and tips I'll keep y'all posted
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Old 12-18-2009, 07:47 AM   #18
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Re: in need of help!

I your distributor cap was allowing moisture you`d have carbon tracks and it would run rough at all speeds.It sounds like it`s not getting the spark it needs when advance matters.I believe either the timing is off or it`s not advancing.This may cost nothing to fix.
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Old 12-18-2009, 08:47 AM   #19
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Re: in need of help!

Depending on how neglected this truck was before you got it it may just have furry contacts under the distributor cap.

Take it off and peek under there. If the contacts are furry you can get by with scraping them clean with your pocket knife. If that fixes the problem go get a new, quality cap and replace it.
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