2000 GMC sluggish on hot restart - Page 2 - 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> Engine> Modern Electronic Engines
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #16 (permalink)  
Old 11-13-2013, 02:31 PM
Rhansen's Avatar
Footbraker
 
Last photo:
Join Date: Jan 2004
Location: Davenport, Iowa
Age: 45
Posts: 590
Wiki Edits: 0

Thanks: 3
Thanked 5 Times in 5 Posts
It doesn't seem to matter whether it sits for a few minutes or if I restart it immediately, it still acts weird on hot restarts - but only for a short time...

No funny noises/lifter clack (even with the doghouse off). Has 40 psi of oil pressure at a hot idle if the gauge is to be believed.

The fuel trim readings were not from when the truck was acting up, first on my list were fuel pressure, O2 sensors, MAF and coolant temp. sensor. Looked at fuel trims as an afterthought....

Another possibility is that the new 'spider' is leaking (bad out of the box??)

Changed the plugs, all had a dark "stripe" that I am assuming is where they lined up with the intake valve.



top left is #1, bottom right is #8



cap & rotor

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 11-14-2013, 12:44 PM
Registered User
 
Last photo:
Join Date: Nov 2006
Location: Woodstock
Posts: 991
Wiki Edits: 0

Thanks: 2
Thanked 90 Times in 82 Posts
I cant see the contacts between the rotor and the cap, but does that contact between the rotor and the center coil feed button look blackened?

I'm wondering if we have a coil issue here.

3 Winters ago, one my 97 ecab 2wd L31, the truck would feel as though it wasnt getting enough fuel. Fuel pressure, poppets, fuel filter all checked out.

I was getting desperate. I took the coil off of my 97 rcsb and tossed it on the 97 ecsb and Voila, no more issue.

GM p/n for an OEM Delco coil is 10489421 and its $42.00 from Rock Auto as is GM PArts Directs price.
Aitex is $38
Delphi is $36
Ultrapower is $21

I would go with a Delco and all OEM parts ESP. for ignition parts. These 1996-2003 Vortec 4.3,305,350 and 454 all use teh same basic coil setup. It is extremely hot compared to older coils. In fact its the same coil as used in the LT1/LT4. There is a reason that GM went Coil Near Plug.

This is frustrating. No codes or pending, new plugs a year ago, CSFI poppets to MPFI mini-injector conversion done.

The more and more I think about it, I'm thinking coil.

When it acts up, what does it do if you hold the throttle to theboards?

peace
Hog
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 11-14-2013, 11:14 PM
Registered User
 
Join Date: Jun 2013
Location: il
Age: 27
Posts: 106
Wiki Edits: 0

Thanks: 27
Thanked 6 Times in 6 Posts
looks like 4 plugs are on the rich side,,, theres signs of fouled plugs,,,,, I would look into coil,,, coil would also do this once the engine is warmed up,,,,had a truck that would misfire when its hot and it was the coil acting up when it was hot,,, so I would check ohm resistance when coil is cold and then once its hot, ,,,
Reply With Quote Quick reply to this message
  #19 (permalink)  
Old 11-18-2013, 08:01 AM
Rhansen's Avatar
Footbraker
 
Last photo:
Join Date: Jan 2004
Location: Davenport, Iowa
Age: 45
Posts: 590
Wiki Edits: 0

Thanks: 3
Thanked 5 Times in 5 Posts
Quote:
Originally Posted by Hogg View Post
I cant see the contacts between the rotor and the cap, but does that contact between the rotor and the center coil feed button look blackened?



When it acts up, what does it do if you hold the throttle to theboards?
I thought the contact looked normal, more of a smudge than blackened.

If I hold the throttle to the floor (when it's acting up) the misfire becomes more pronounced, the problem will persist longer than if you just use light throttle, and it will pop/sputter a little out of the exhaust.

Quote:
Originally Posted by 81camaro1
looks like 4 plugs are on the rich side
hard to tell from a pic (plus that pic is kind of dark) but the plugs were very uniform. Look at #'s 3, 5, and 7 and imagine you are rotating the plug. They're all dark on one side, light on the other. They looked rich to me too but never seen it just on half the plug before...
Will have to pull some of the new ones out later in the week (have to go out of town for a few days) and see if they look similar.
Reply With Quote Quick reply to this message
  #20 (permalink)  
Old 11-23-2013, 07:24 AM
Registered User
 
Join Date: May 2013
Posts: 12
Wiki Edits: 0

Thanks: 4
Thanked 0 Times in 0 Posts
i didnt read all the posts so forgive me if youve covered this but, if you can take a snapshot of ALL the data(while acting up) and upload it on here so we can see whats happening i feel we could come to a better conclusion. it seems by your discription it's happening while it's still in open loop. what's your coolant temp at while it's happening(on the scanner, not the dash) i've replaced a bunch of o2 on these things that hang lean and cause it to run rich or vice versa. what happens if your reset all the adaptives? will it run normal for a while untill it re-learns some bad info?
Reply With Quote Quick reply to this message
  #21 (permalink)  
Old 10-03-2014, 04:12 PM
Rhansen's Avatar
Footbraker
 
Last photo:
Join Date: Jan 2004
Location: Davenport, Iowa
Age: 45
Posts: 590
Wiki Edits: 0

Thanks: 3
Thanked 5 Times in 5 Posts
So 5k miles later the van starts running more poorly, won't rev cleanly in park/neutral and has a definite flat spot at tip in. Still no DTC codes.
Had the bright idea to unplug the MAF and it starts running better immediately so I cleaned it and the van ran well for about 10 mins then back to being a slug.
One new MAF later and voila, problem solved.
Reply With Quote Quick reply to this message

Recent Modern Electronic Engines posts with photos

Quick Reply
Message:
Options

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:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
2000 gmc 4x4 novakidd 63 Hotrodding Basics 4 01-28-2007 06:55 PM
2000 GMC shifts rough 85CHEVY Transmission - Rearend 1 08-16-2005 12:52 PM
Hot restart problems willowbilly3 Engine 7 06-19-2005 09:46 AM
Fuel gauge on my 2000 GMC Maverick General Rodding Tech 1 03-05-2004 11:44 PM
Headers on 2000 GMC Maverick Engine 3 09-21-2003 09:10 PM


All times are GMT -6. The time now is 01:27 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.