66 Chevy truck backfiring - The 1947 - Present Chevrolet & GMC Truck Message Board Network

forverfate · 06-06-2012, 01:54 AM

Does anybody have an idea why my 66 c10 would be backfiring only at 2500 rpms and above ? Timing off ? Possible fuel fuel getting colged ? Could it be ****ty gas ? I have recently put new edelbrock air gap manifold and new edelbrock 1406 carb , new fuel filter . Any suggestions would help .
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**joedoh** · 06-06-2012, 01:57 AM

under load/accel only? vacuum leak or lean mixture or both.

forverfate · 06-06-2012, 01:58 AM

Accel only .
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hugger6933 · 06-06-2012, 07:47 AM

check the firing order may be cross wired look for vac leaks with some carb cleaner with the engine runnig if you spray at the motor the it changes tune then you found your leak. plug wires canbreak down as cause the under load miss as well

**joedoh** · 06-06-2012, 08:22 AM

I have seen a lot of newly installed carbs where they get cranked down too tight and it causes a vacuum leak at the base. also, make sure you have plugged all open vacuum ports on the new intake and carb.

awbrown · 06-06-2012, 08:41 AM

did the problem start the same day you installed the intake and carb????

forverfate · 06-12-2012, 05:03 PM

Thanks everybody for the help ! It was my plug wires . One got burnt all the way to the metal . Should checked that first .
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forverfate · 06-12-2012, 05:14 PM

So I am looking for a new Hei for my 66 and I have a 350 v8 . Looking for some input before I buy one. Room is tight and was going to get a small cap or skinnier one. I have no idea about this. I am not going the cheap route , and would like an American made one ,if possible !
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jchav62 · 06-12-2012, 05:53 PM

I've run regular GM HEI distributors on these trucks. I have HEI in my '62 and the '65 also had HEI until recently. Converted that one the TBI and used the newer distributor.

TopFuel1966 · 06-12-2012, 06:22 PM

Quote:

Originally Posted by forverfate

So I am looking for a new Hei for my 66 and I have a 350 v8 . Looking for some input before I buy one. Room is tight and was going to get a small cap or skinnier one. I have no idea about this. I am not going the cheap route , and would like an American made one ,if possible !
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That would be spelled MSD

gimmy 64 · 06-12-2012, 07:42 PM

MSD streetfire resonably priced and works great. you don't need a polished billet distrubtor because you can't see it anyway lol. when you install it put dist.in first and then put cap on it will fit fine.

06-06-2012, 01:54 AM	#1
forverfate Registered User Join Date: May 2012 Location: san diego Posts: 17	66 Chevy truck backfiring Does anybody have an idea why my 66 c10 would be backfiring only at 2500 rpms and above ? Timing off ? Possible fuel fuel getting colged ? Could it be ***ty gas ? I have recently put new edelbrock air gap manifold and new edelbrock 1406 carb , new fuel filter . Any suggestions would help . Posted via Mobile Device* Posted via Mobile Device

06-06-2012, 01:57 AM	#2
joedoh Senior Member Join Date: May 2007 Location: Doodah Kansas Posts: 7,761	Re: 66 Chevy truck backfiring under load/accel only? vacuum leak or lean mixture or both. __________________ the mass of men live lives of quiet desperation if there is a problem, I can have it. new project WAYNE http://67-72chevytrucks.com/vboard/s...d.php?t=844393

06-06-2012, 01:58 AM	#3
forverfate Registered User Join Date: May 2012 Location: san diego Posts: 17	Re: 66 Chevy truck backfiring Accel only . Posted via Mobile Device

06-06-2012, 07:47 AM	#4
hugger6933 Registered User Join Date: Oct 2008 Location: Marianna Arkansas Posts: 7,261	Re: 66 Chevy truck backfiring check the firing order may be cross wired look for vac leaks with some carb cleaner with the engine runnig if you spray at the motor the it changes tune then you found your leak. plug wires canbreak down as cause the under load miss as well

06-06-2012, 08:22 AM	#5
joedoh Senior Member Join Date: May 2007 Location: Doodah Kansas Posts: 7,761	Re: 66 Chevy truck backfiring I have seen a lot of newly installed carbs where they get cranked down too tight and it causes a vacuum leak at the base. also, make sure you have plugged all open vacuum ports on the new intake and carb. __________________ the mass of men live lives of quiet desperation if there is a problem, I can have it. new project WAYNE http://67-72chevytrucks.com/vboard/s...d.php?t=844393

06-06-2012, 08:41 AM	#6
awbrown Registered User Join Date: Aug 2009 Location: Detroit MI Posts: 1,209	Re: 66 Chevy truck backfiring did the problem start the same day you installed the intake and carb????

06-12-2012, 05:03 PM	#7
forverfate Registered User Join Date: May 2012 Location: san diego Posts: 17	Re: 66 Chevy truck backfiring Thanks everybody for the help ! It was my plug wires . One got burnt all the way to the metal . Should checked that first . Posted via Mobile Device __________________

06-12-2012, 05:14 PM	#8
forverfate Registered User Join Date: May 2012 Location: san diego Posts: 17	What hei disturbtor is the best for my truck ? So I am looking for a new Hei for my 66 and I have a 350 v8 . Looking for some input before I buy one. Room is tight and was going to get a small cap or skinnier one. I have no idea about this. I am not going the cheap route , and would like an American made one ,if possible ! Posted via Mobile Device __________________

06-12-2012, 05:53 PM	#9
jchav62 1962 C-10 Join Date: Apr 2005 Location: Las Vegas, New Mexico Posts: 4,978	Re: 66 Chevy truck backfiring I've run regular GM HEI distributors on these trucks. I have HEI in my '62 and the '65 also had HEI until recently. Converted that one the TBI and used the newer distributor. Attached Images __________________ Joseph Chavez "See the USA in a Chevrolet!!" ......................_____ .........________//__{\_____ ,,,,,,,/__(O)___//___/__(O)_/ 1962 C10 Shortbed Fleetside 327/th350 GV overdrive 1974 C10 Longbed Fleetside 350/th350 "The Trash Truck" 1999 Chevy 2500 OBS, Longbed 5.7/4L80E 4x4 2015 GMC Sierra SLE 1500 4x4

06-12-2012, 07:42 PM	#11
gimmy 64 Registered User Join Date: Sep 2009 Location: menifee california Posts: 788	Re: 66 Chevy truck backfiring MSD streetfire resonably priced and works great. you don't need a polished billet distrubtor because you can't see it anyway lol. when you install it put dist.in first and then put cap on it will fit fine.



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