The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-06-2004, 04:13 PM   #1
jorgensensc
Registered User
 
jorgensensc's Avatar
 
Join Date: Jul 2003
Location: Cypress, Tx
Posts: 4,005
Carb problems. Help.

I recently did a total tunup on my truck because the wires were burnt from the manifolds. I had a deiseling problem develop before I did all the work and I figured this would help fix it. Needless to say it didn't. I'm soo frustrated since I can't seem to dial this thing in right. It's a 350 with an edelbrock RPM Air Gap intake and a edelbrock 1406 600cfm carb. I replaced the wires with all new good ones and plugs, fuel filter,exhaust manifold gaskets, etc. I have even been trying to adjusting the carb without any luck. I set the timing to 8 degrees BTDC. At a stoplight if you mash the gas it will sputter and cough, and even sometimes die. Even sometimes if you lightly press the gas it will die out. Not all the time, but sometimes. When I first start driving(whether the truck is at operating temp or not) it will backfire once through the carb, but doesn't do it again after the first time. When I go to turn it off it wants to diesel sometimes, not all the time, but sometimes. And it is usually one of those long ass ones that you think will never end. The truck runs great when above idle and on the road. Performs great with no hesitation at all. Please help me figure out this problem I am getting so frustrated, not to mentioned embarassed when my beautiful truck stalls in the middle of an intersection coming off a light or starts deiseling in front of a store.Thanks to all the advice and help in advance.
Shawn
__________________
1972 C20 Suburban- Big Blue Betty
'56 Chevy Bel Air Sedan- Frame up Restoration

-What would you attempt to achieve if you knew you could not fail?-

-I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door-

R.I.P. EAST SIDE LOW LIFE
jorgensensc is offline   Reply With Quote
Old 08-06-2004, 04:43 PM   #2
HuggerCST
Registered User
 
HuggerCST's Avatar
 
Join Date: Jul 2001
Location: North Louisiana
Posts: 4,501
Most of the time, as you probably know, dieseling is caused by either timing, or idling too high. Make sure you check the timing with the vac. line unhooked and plugged at the dist, and also make sure it is idled down to around 600 rpm. 2nd check for vacuum leaks around the carb area, as that could cause those symptoms. I'm not too familiar with that carb, but my guess is that you will find a vacuum leak somewhere, maybe even internal.
EDIT: Also, check your vac. advance. And to stop the dieseling untill you find the problem, kill it while it's in gear.
__________________
Wynne
70 CST short fleet Hugger orange & white, 350/350, ps, pb, air, tilt, tach/vac/speedwarning, original buckets, AM/FM, oak bed floor, shoulder belts, 3.5"/5.5" drop, 20" American Racing VN425s.
Build thread
53 Chevy shortbed
69 Camaro

Click here to subscribe
Chevy GMC International Truck Club Louisiana Charter Member
http://www.louisianaclassictruckclub.com

Last edited by HuggerCST; 08-06-2004 at 04:45 PM.
HuggerCST is offline   Reply With Quote
Old 08-06-2004, 05:19 PM   #3
68 Suburban
Registered User
 
68 Suburban's Avatar
 
Join Date: Oct 2000
Location: From Chicago, Live in Phoenix, AZ
Posts: 6,802
I was having the same type of problem 4 years agon and I was blaming the carb. It turned out to be the distributor was warn and had a fluctuating timing problem. I switch the regular distributor and have not had the problem since.

As for the dieseling, I have heard that can be caused by carbon build up in the chambers and when the engine gets hot enough, you have the dieseling run on problem.

Also, I don't know what your engine set up is, but if it is close to stock, I found the 1406 carb needed to be tuned down two steps. Out of the box, it was way to rich for my engine. The good thing is, once you get the tuning kit, the carb is easy to tune.

The carb out of the box is at the 1 position, I have mine set a the 14 position.
__________________
Just sitting here contemplating contemplation.
68 Suburban is offline   Reply With Quote
Old 08-06-2004, 06:15 PM   #4
jorgensensc
Registered User
 
jorgensensc's Avatar
 
Join Date: Jul 2003
Location: Cypress, Tx
Posts: 4,005
Thanks for the suggestions so far guys, I am going to go mess with for a little bit tonight.
__________________
1972 C20 Suburban- Big Blue Betty
'56 Chevy Bel Air Sedan- Frame up Restoration

-What would you attempt to achieve if you knew you could not fail?-

-I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door-

R.I.P. EAST SIDE LOW LIFE
jorgensensc is offline   Reply With Quote
Old 08-06-2004, 07:45 PM   #5
71swb4x4
Senior Member
 
71swb4x4's Avatar
 
Join Date: Nov 2003
Location: Brookings, SD
Posts: 10,497
Sounds like you finally have your reason to go TPI
__________________
Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs.
71swb4x4 is offline   Reply With Quote
Old 08-06-2004, 08:25 PM   #6
jorgensensc
Registered User
 
jorgensensc's Avatar
 
Join Date: Jul 2003
Location: Cypress, Tx
Posts: 4,005
I know I know. TPI sooner or later, but then I want a new overdrive tranny, then rear end, it never stops
__________________
1972 C20 Suburban- Big Blue Betty
'56 Chevy Bel Air Sedan- Frame up Restoration

-What would you attempt to achieve if you knew you could not fail?-

-I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door-

R.I.P. EAST SIDE LOW LIFE
jorgensensc is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 05:58 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com