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 01-07-2012, 10:09 AM   #1
kellytheaker
Registered User
 
Join Date: Dec 2009
Location: ontario Canada
Posts: 412
87 chev 1/2 350 F/I cold start surging idle

the truck will go to fast idle and then drop to almost stall then pick itsel f up again and continue - when warm it improves but still a surge of up and down - just not as severe - is this an o2 sensor or ? the truck seems to always hunt for an even idle - thanks
kellytheaker is offline   Reply With Quote
Old 01-07-2012, 11:01 AM   #2
ChevyTech
Registered User
 
Join Date: May 2004
Location: Minnesota
Posts: 4,621
Re: 87 chev 1/2 350 F/I cold start surging idle

A common cause of an idle that hunts up and down on these trucks is a lean fuel mixture, usually from low fuel pressure.

It is also common for the gasket under the TBI unit to leak vacuum causing idle issues.

Here is a thread on this topic:
http://67-72chevytrucks.com/vboard/s...t=surging+idle
__________________
For those of you that are wondering why you are not getting replies to your thread:
Did you give the model, year, engine, fuel system type, and transmission information?
If it is modified from what came stock from the factory, let us know that too.
ChevyTech is offline   Reply With Quote
Old 01-07-2012, 03:44 PM   #3
kellytheaker
Registered User
 
Join Date: Dec 2009
Location: ontario Canada
Posts: 412
Re: 87 chev 1/2 350 F/I cold start surging idle

thank you - i will certainly check the fuel pressure , tbi base and reg , then on to additional post info i read the other tips if its not fuel related , thanks it s a start .
kellytheaker 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 07:10 AM.


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