Problems---HEI, and top question--HELP! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bigpig72CST · 10-10-2006, 05:58 PM

I upgraded my 72 Blazer to HEI and am now having a problem with the vehicle as soon as I try to push on the pedal. It falls flat, and dies out. I also did a complete tune up and had the quadrajunk rebuilt. Has anyone else out there had this problem, or know how I could look to fix it? I have been considering just buying a new carb to see if it would fix the problem, or if there is a fuseable link or anything that I could check first.

Also, my Blazer currently has a double wall top, and it is going bad around the hinges. I have found a single wall top for what I think is a decent price, but I was wondering if it would bolt up? Or, if there is an easy fix for the top I have? If the double wall is my only option, does anyone have one for sale?

71jimmy · 10-10-2006, 06:12 PM

Oh, I bet that's your dizzy, not your carb!

The mounting holes bt. the two tops are not in the same location. You would need to drill new holes into your bedside, or into the single wall top. Fiberglass repair is simple and straight forward, you can get all the supplies at your local auto part store ussually.

Careful wanting to buy or sell without being a paying customer, someone IS watching. Go over to the classified section, sometimes you can find tops for sale there.

Goold Luck and welcome to the site.

blazerparts · 10-10-2006, 06:21 PM

Did you upgrade the hot wire to the hei? 10 guage is recommended I think.

70rs/ss · 10-10-2006, 06:30 PM

make sure you didn't use the factory resistor wire that went to the coil in your factory harness to feed the hei, cause it only allows 6-8 volts and an hei needs a full12-13 volts to run properly. Run a new bigger guage wire with switched power to the hei and your stumble will probably go away.

RustyParts · 10-10-2006, 08:40 PM

If you used an old HEI with some miles on it, you may need to replace the pickup coil in the bottom of the distributor. Everytime the vehicle accelerates the pickup coil turns because of the vacuum advance and the two wires connected to the pickup coil bend. After repeated use the wires will actually break several strands and under acceleleration they will loose connection momentarily causing the vehicle to stumble. Whew!!!

bigpig72CST · 10-11-2006, 11:21 AM

Thanks for all the help, I appreciate it. I never even considered changing out the coil wire.

I'll try that and see if it helps. I may end up buying a new carb anyway. I have a new Edelbrock 650 on my 79 4x4, and I love it compared to the quadraj. Still, it will be nice to get the Blazer moving at more than an idle.

So you think that I could potentially patch around the hinge for the rear liftgate on a double wall? I have found a good single wall top from a guy around here pretty cheap, and I might get it anyway.

Sorry about asking if anyone had anything for sale, I didn't realize, so thanks for the info!

Critter · 10-11-2006, 01:02 PM

As far as the ignition goes, there is a very convinient place to run a new wire. I think there is even a FAQ topic over it. Basically there is an unused terminal on the fuse box that comes straight from the ignition key (it is labeled Ignition). However, it is unfused. Just solder up a 10 ga wire with an inline fuse holder and female flag connectors on both ends, one to the HEI and the other to the fuse box. Bam, your done.

krue · 10-11-2006, 04:14 PM

That's the way I did mine.

LUV2XCLR8 · 10-11-2006, 04:58 PM

Quote:

Originally Posted by 71jimmy

The mounting holes bt. the two tops are not in the same location.

But ...................................... He has a 72, and some come pre-drilled
for both types of tops, does your bed rails have lots of mounting holes?

jaros44sr · 10-11-2006, 07:29 PM

Quote:

Originally Posted by LUV2XCLR8

But ...................................... He has a 72, and some come pre-drilled
for both types of tops, does your bed rails have lots of mounting holes?

Hey, your right. I have big round holes and slots with moveable drilled and tapped holes. Never even gave that a thought!! Thanks for the info. guys, you're the best, now I can buy a single wall... does it ever end?

florida4x4 · 10-12-2006, 09:56 AM

I converted mine with a reman from advance auto. replaced it twice. engine never ran perfectly. last time I went to replace it I asked if I could "trade up" to an accell dizzy. they said sure and I paid an extra $10 and $50 for the super coil (which is not necessary). I wish I had done it the first time around. It came with springs to adjust the mechanical advance and an adjustable vacuum advance. Can't beat the way it runs now. Well maybe with a few hunnered on a MSD... the accell fixed a lot of drivability problems with the OEM HEI. ...my .02...

bigpig72CST · 10-12-2006, 10:13 AM

I'll have to take a look and see if I have holes for either. Thanks for the tip, I wouldn't have known to even look. I'll probably get the single wall top from that guy, I have heard that they are better than the double wall anyway, right?

Sorry to keep asking the same question, but has anyone ever patched the area around the hinges on a double wall??? How easy is it?

10-10-2006, 05:58 PM	#1
bigpig72CST Registered User Join Date: Oct 2006 Location: Des Moines Posts: 55	Problems---HEI, and top question--HELP! I upgraded my 72 Blazer to HEI and am now having a problem with the vehicle as soon as I try to push on the pedal. It falls flat, and dies out. I also did a complete tune up and had the quadrajunk rebuilt. Has anyone else out there had this problem, or know how I could look to fix it? I have been considering just buying a new carb to see if it would fix the problem, or if there is a fuseable link or anything that I could check first. Also, my Blazer currently has a double wall top, and it is going bad around the hinges. I have found a single wall top for what I think is a decent price, but I was wondering if it would bolt up? Or, if there is an easy fix for the top I have? If the double wall is my only option, does anyone have one for sale?

10-10-2006, 06:12 PM	#2
71jimmy Registered User Join Date: Mar 2004 Location: Sacramento, CA Posts: 1,084	Re: Problems---HEI, and top question--HELP! Oh, I bet that's your dizzy, not your carb! The mounting holes bt. the two tops are not in the same location. You would need to drill new holes into your bedside, or into the single wall top. Fiberglass repair is simple and straight forward, you can get all the supplies at your local auto part store ussually. Careful wanting to buy or sell without being a paying customer, someone IS watching. Go over to the classified section, sometimes you can find tops for sale there. Goold Luck and welcome to the site. __________________ '71 Jimmy, 350, SM465, NP205, 2in Tuff Country lift, 33s on rallies, TBI, softtop and hardtop "If life was fair you'd be able to afford one of each and a garage large enough to house them all."

10-10-2006, 06:21 PM	#3
blazerparts No,I DON'T have Tourett's Join Date: Mar 2005 Location: Reno, NV Posts: 556	Re: Problems---HEI, and top question--HELP! Did you upgrade the hot wire to the hei? 10 guage is recommended I think. __________________ '72 K5 CST 350/350 Daily Driver '69 GMC3500 Camper Special CST Flatbed 396/400 Upgraded to show truck '69 GMC 2500 L6292, 3spd beater

10-10-2006, 06:30 PM	#4
70rs/ss Registered User Join Date: Dec 2004 Location: Northern AZ Posts: 7,271	Re: Problems---HEI, and top question--HELP! make sure you didn't use the factory resistor wire that went to the coil in your factory harness to feed the hei, cause it only allows 6-8 volts and an hei needs a full12-13 volts to run properly. Run a new bigger guage wire with switched power to the hei and your stumble will probably go away.

10-10-2006, 08:40 PM	#5
RustyParts Registered User Join Date: May 2006 Location: Wyman, Kentucky Posts: 403	Re: Problems---HEI, and top question--HELP! If you used an old HEI with some miles on it, you may need to replace the pickup coil in the bottom of the distributor. Everytime the vehicle accelerates the pickup coil turns because of the vacuum advance and the two wires connected to the pickup coil bend. After repeated use the wires will actually break several strands and under acceleleration they will loose connection momentarily causing the vehicle to stumble. Whew!!!

10-11-2006, 11:21 AM	#6
bigpig72CST Registered User Join Date: Oct 2006 Location: Des Moines Posts: 55	Re: Problems---HEI, and top question--HELP! Thanks for all the help, I appreciate it. I never even considered changing out the coil wire. I'll try that and see if it helps. I may end up buying a new carb anyway. I have a new Edelbrock 650 on my 79 4x4, and I love it compared to the quadraj. Still, it will be nice to get the Blazer moving at more than an idle. So you think that I could potentially patch around the hinge for the rear liftgate on a double wall? I have found a good single wall top from a guy around here pretty cheap, and I might get it anyway. Sorry about asking if anyone had anything for sale, I didn't realize, so thanks for the info!

10-11-2006, 01:02 PM	#7
Critter Future TOTM Winner Join Date: Aug 2006 Location: Bulverde, TX Posts: 2,692	Re: Problems---HEI, and top question--HELP! As far as the ignition goes, there is a very convinient place to run a new wire. I think there is even a FAQ topic over it. Basically there is an unused terminal on the fuse box that comes straight from the ignition key (it is labeled Ignition). However, it is unfused. Just solder up a 10 ga wire with an inline fuse holder and female flag connectors on both ends, one to the HEI and the other to the fuse box. Bam, your done. __________________ 72 Chevy CST K5 HIGHLANDER BLAZER Getting a 6.0,NV4500,NP205,14BFF (Currently laying all over the place in little pieces) 72 Chevy swb step-side "LS" 6.0 Here's a build thread of sorts 2002 HD2500 Crew Cab, 8.1L Allison 4x4 Daily Driver Check it out www.lsdyno.com Last edited by Critter; 10-11-2006 at 01:03 PM.

10-11-2006, 04:14 PM	#8
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Re: Problems---HEI, and top question--HELP! That's the way I did mine. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

10-12-2006, 09:56 AM	#11
florida4x4 Registered User Join Date: Dec 2002 Location: tally FL Posts: 74	Re: Problems---HEI, and top question--HELP! I converted mine with a reman from advance auto. replaced it twice. engine never ran perfectly. last time I went to replace it I asked if I could "trade up" to an accell dizzy. they said sure and I paid an extra $10 and $50 for the super coil (which is not necessary). I wish I had done it the first time around. It came with springs to adjust the mechanical advance and an adjustable vacuum advance. Can't beat the way it runs now. Well maybe with a few hunnered on a MSD... the accell fixed a lot of drivability problems with the OEM HEI. ...my .02... __________________ 1972 GMC Jimmy - 383SBC \| TH350-NP203-NP205 \| D60PL \| 14FF Detroit \| 42 TSL's \| 4Xeyes \| Heavy FOotE "Trail in. Trash out." Florida4x4 dot Com

10-12-2006, 10:13 AM	#12
bigpig72CST Registered User Join Date: Oct 2006 Location: Des Moines Posts: 55	Re: Problems---HEI, and top question--HELP! I'll have to take a look and see if I have holes for either. Thanks for the tip, I wouldn't have known to even look. I'll probably get the single wall top from that guy, I have heard that they are better than the double wall anyway, right? Sorry to keep asking the same question, but has anyone ever patched the area around the hinges on a double wall??? How easy is it?



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