![]() |
Register or Log In To remove these advertisements. |
|
|
![]() |
|
Thread Tools | Display Modes |
|
![]() |
#1 |
Registered User
![]() Join Date: Sep 2005
Location: Oklahoma USA
Posts: 1,000
|
Engine Problem Opinions
Situation: Big block from a 72 GMC rebuilt many years ago, has about 150 miles on it. Runs and drives OK, but idles rough when stopped and in gear. No rough idle when stopped and in park or neutral. Have had plugs and wire replaced, but to no avail. I'm not an engine guy....stuck valve? Bent rod?
__________________
1968 Custom SWB, 327/3 speed OTC 1969 CST LWB, 402/400 1970 CST LWB, 402/400 1970 Sierra Grande LWB, 350/350 1971 Cheyenne LWB, 350/350 1972 Cheyenne Super LWB, 402/400 1972 Sierra Grande LWB, 402/400 1979 Silverado LWB, 350/350 1984 Suburban 1990 454 SS 1991 Silverado, X-cab, 4.3/5 speed Getrag 2005 Silverado Crew Cab Corvettes: 75, 77, 78, 93, 96 |
![]() |
![]() |
![]() |
#2 |
PROJECT 7DEUCE
![]() Join Date: Dec 2002
Location: GRANTS PASS OR
Posts: 21,608
|
Re: Engine Problem Opinions
Sounds like the carb may need to be adjusted hows the choke???
__________________
GO BIG GREEN ![]() MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P.. |
![]() |
![]() |
![]() |
#3 |
Registered User
![]() Join Date: Sep 2005
Location: Oklahoma USA
Posts: 1,000
|
Re: Engine Problem Opinions
Not sure, but that would be a preferred solution. JC
__________________
1968 Custom SWB, 327/3 speed OTC 1969 CST LWB, 402/400 1970 CST LWB, 402/400 1970 Sierra Grande LWB, 350/350 1971 Cheyenne LWB, 350/350 1972 Cheyenne Super LWB, 402/400 1972 Sierra Grande LWB, 402/400 1979 Silverado LWB, 350/350 1984 Suburban 1990 454 SS 1991 Silverado, X-cab, 4.3/5 speed Getrag 2005 Silverado Crew Cab Corvettes: 75, 77, 78, 93, 96 |
![]() |
![]() |
![]() |
#4 |
Franko72
Join Date: May 2004
Location: Cincinnati,Ohio
Posts: 471
|
Re: Engine Problem Opinions
carb. adjustment would be my next thought.be sure timing is correct.check all plugs for firing properly.check for intake or carb. gasket leaks, vac. lines also.
install a new dist. cap and button. Basic checks and tune up.
__________________
![]() 1972 C20 cheyenne Super 402 BB/400 turbo LWB A/C Tilt, Cruise Control, Saddle tanks, Tach My Home Page Better to burn out than it is to rust |
![]() |
![]() |
![]() |
#5 |
No,I DON'T have Tourett's
Join Date: Mar 2005
Location: Reno, NV
Posts: 556
|
Re: Engine Problem Opinions
Depends on your definition of rough. My 396 runs smooth as silk, but in gear at idle, it bounces a little.
__________________
'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 |
![]() |
![]() |
![]() |
#6 |
Registered User
Join Date: May 2005
Location: Brazoria, Texas
Posts: 60
|
Re: Engine Problem Opinions
It could possibly be a vacuum leak on the intake manifold or the carburetor somewhere. I've taken carburetor cleaner & sprayed around the intake while it's running. If the engine speeds up or bogs down, you have found the leak. Does it have a stock cam or an aftermarket?
__________________
1969 GMC C-1500 1972 Rally Nova 1988 Monte Carlo SS 2004 GMC 2500 Crew Cab |
![]() |
![]() |
![]() |
#7 |
Registered User
![]() Join Date: Sep 2005
Location: Oklahoma USA
Posts: 1,000
|
Re: Engine Problem Opinions
We got her running...smoothly. Might have had some junk in one of the idle jets. Thanks to all. JC
__________________
1968 Custom SWB, 327/3 speed OTC 1969 CST LWB, 402/400 1970 CST LWB, 402/400 1970 Sierra Grande LWB, 350/350 1971 Cheyenne LWB, 350/350 1972 Cheyenne Super LWB, 402/400 1972 Sierra Grande LWB, 402/400 1979 Silverado LWB, 350/350 1984 Suburban 1990 454 SS 1991 Silverado, X-cab, 4.3/5 speed Getrag 2005 Silverado Crew Cab Corvettes: 75, 77, 78, 93, 96 |
![]() |
![]() |
![]() |
Bookmarks |
|
|