87 Chevy Pickup Timing Problem - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum

Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Electrical
User Name
lost password?   |   register now

LinkBack Thread Tools
  #1 (permalink)  
Old 10-15-2003, 06:25 PM
Registered User
Join Date: Oct 2003
Location: VA
Posts: 1
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
87 Chevy Pickup Timing Problem

Have 87 Chevy full size pickup 3/4 ton 4wd 350 TBI - engine and truck are all stock. Truck has erratic idle. I have tried to set timing but when I try to put in bypass mode the truck shuts off and will not start at all. When engine is running and have pulled the bypass connector the truck shuts off immediately. Truck is showing a code 42 - have installed rebuilt dist with new ignition module/est. Have replaced ECM (did not replace PROM). Installed new external coil, new O2 sensor. I replaced the IAC valve thinking it would solve the idle problem but it did not. Service manual said wires from dist to ECM has open circuit - but checked continuity on all four wires and there is no open circuit. Truck does have slight hesitation from idle and very slight bit of surge at speed over 45. When truck is cold it is very cold natured. The only way I can get it to run somewhat ok is by setting timing at 22 degrees, but it still dies no matter where it is set when I pull the bypass connector.

Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 10-17-2003, 08:43 AM
New Member
Join Date: Sep 2003
Location: webster mass
Posts: 19
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
code 42 was set when u unplugged the timing wire. did u check your egr valve? see if it is sticking or just plain weak.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 10-19-2003, 11:04 AM
dklong's Avatar
Last photo:
Join Date: May 2002
Location: sussex nb canada
Age: 52
Posts: 258
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
when changing ecm's in GM always reuse your old prom !!!!!! the prom is only calibraded for that vechile.
Reply With Quote Quick reply to this message

Recent Electrical posts with photos

Quick Reply

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -6. The time now is 09:57 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.