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 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 10-17-2011, 07:33 PM   #1
savatreatabvr
Registered User
 
savatreatabvr's Avatar
 
Join Date: Oct 2011
Location: phoenix, az
Posts: 508
1976 454 Limping on 7 Clyinders?

At first it smoked after running a while so I adjusted the valves, it seemed to make it smoke worse but after sitting for 2 days I drove it 60 miles round trip and no smoke but now it seems to run on 7 cylinders but not all time, I pulled plugs wires one at a time but not much change in the way it runs. I swear this things possessed! It's always idled low and rough but now since it doesn't smoke I'm thinking it may be the distributor causing it to run this way? I've got a mysterious orange wire coming from the distributor to the fuse box, any idea's one what it is for?
savatreatabvr is offline   Reply With Quote
Old 10-17-2011, 10:34 PM   #2
csb#356
Registered User
 
Join Date: May 2009
Location: Pinehurst, Idaho
Posts: 311
Re: 1976 454 Limping on 7 Clyinders?

Probly the power wire or a tach wire. What terminal is it coming from? Is it an HEI distributor? Have you run a compression test?
csb#356 is offline   Reply With Quote
Old 10-17-2011, 11:16 PM   #3
savatreatabvr
Registered User
 
savatreatabvr's Avatar
 
Join Date: Oct 2011
Location: phoenix, az
Posts: 508
Re: 1976 454 Limping on 7 Clyinders?

No tach, yes HEI, the pics below show the mysterious wire at the distributor and the wire connector with the mysterious wire in the background. The red circle shows where the wire connector plugs in so the mysterious wire is on the outside of the connector. If the mysterious wire is the power wire for the distributor then it didn't come that way from the factory and why didn't they incorporate it into the wire connector? I've run a compression test with 2 cylinders at around 90lbs and the rest around 110 - 120lbs.





Quote:
Originally Posted by csb#356 View Post
Probly the power wire or a tach wire. What terminal is it coming from? Is it an HEI distributor? Have you run a compression test?
savatreatabvr is offline   Reply With Quote
Old 10-17-2011, 11:53 PM   #4
flamingbig10
6.0 powered square
 
flamingbig10's Avatar
 
Join Date: Feb 2008
Location: Mesquite texas
Posts: 3,459
Re: 1976 454 Limping on 7 Clyinders?

red wire Is the coil power wire from the ignition switch the three wire go to the coil to the module inside the distributor cap
__________________
Aaron
1980 c-10 short bed lowered, cammed 6.0, 4l80e 3600 stall, smp tune, wilwoods, and flames best time so far best et 7.86 @87 on motor 7.57 90 on a 75 shot
Build http://67-72chevytrucks.com/vboard/s...d.php?t=283326
flamingbig10 is offline   Reply With Quote
Old 10-18-2011, 12:54 AM   #5
savatreatabvr
Registered User
 
savatreatabvr's Avatar
 
Join Date: Oct 2011
Location: phoenix, az
Posts: 508
Re: 1976 454 Limping on 7 Clyinders?

Could there be an issue with the distributor, the module or any other part of the ignition system? Could the distributor or coil not be pumping out enough voltage to make it run right? Could I possibly have a SB distributor instead of a BB distributor on my 454? Would it even fit?

Quote:
Originally Posted by flamingbig10 View Post
red wire Is the coil power wire from the ignition switch the three wire go to the coil to the module inside the distributor cap
savatreatabvr is offline   Reply With Quote
Old 10-18-2011, 07:53 PM   #6
csb#356
Registered User
 
Join Date: May 2009
Location: Pinehurst, Idaho
Posts: 311
Re: 1976 454 Limping on 7 Clyinders?

Did you get those numbers with the throttle wide open and the engine warmed up? If so I would say 90 is a tad low but not horrible. Also try adding oil to the cylinders that are low and see if it helps bring the compression up. It could be that you have worn rings and could also be something in the distributor making it run rough or miss. Burnt plug wire, fouled plug etc. In correct timing. Lots of things to check.
csb#356 is offline   Reply With Quote
Old 11-08-2011, 06:25 PM   #7
savatreatabvr
Registered User
 
savatreatabvr's Avatar
 
Join Date: Oct 2011
Location: phoenix, az
Posts: 508
Re: 1976 454 Limping on 7 Clyinders?

It was warmed up but one of the problems I think was the PCV valve. It was in the valve cover without the baffle so I was told the PCV valve was sucking oil into it. I switched it over and it stopped smoking as much but at the same time I changed job locations and it's only 5 miles round trip, before it was 20 miles one way so I just may not be driving it long enough now for it to get fully warmed up. In a few days I'm driving to Payson which is about 240 miles round trip so I'll be able to tell if my theory is correct.

Quote:
Originally Posted by csb#356 View Post
Did you get those numbers with the throttle wide open and the engine warmed up? If so I would say 90 is a tad low but not horrible. Also try adding oil to the cylinders that are low and see if it helps bring the compression up. It could be that you have worn rings and could also be something in the distributor making it run rough or miss. Burnt plug wire, fouled plug etc. In correct timing. Lots of things to check.
savatreatabvr 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 09:45 PM.


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