Glow plugs fire while driving, sometimes wont fire when starting - Diesel Place : Chevrolet and GMC Diesel Truck Forums
 
Home Forum Market Place Garage Tuning Library DTC Tool Register Vendors
Go Back   Diesel Place : Chevrolet and GMC Diesel Truck Forums > GM Diesel Engines > 6.5L Diesel Engine
Register FAQ Forum Rules My Replies My Threads Mark Forums Read Advertise

6.5L Diesel Engine Discuss the 6.5 GM diesel engine & associated components. Automatic transmission questions & problems belong in the 4L80/85 - 4L60E - 6L90 Transmission Forum

DieselPlace.com is the premier Duramax Diesel Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools
Old 11-24-2012, 09:25 AM   #1 (permalink)
SickSpeedMonte
Glow Plug
 
SickSpeedMonte's Avatar
 
Join Date: Oct 2010
Posts: 290
iTrader Score: 0 reviews

Glow plugs fire while driving, sometimes wont fire when starting

1993 K3500 6.5TD. The truck sat for a while before I bought it, ~1yr.

Sometimes when I try to start it in the morning, the GP light won't come on and the GP's wont lite off. Sometimes if I bump the engine over with the starter, they will then turn on. Other times I have to pop the hood and poke the connector to the GP controller from the harness. That sounds like a bad connection, but when I stop pushing on the connector, the GP's stay on for the correct amount of time.

So I lived with that for a little while, and now I went to start the truck the other day and the batteries were dead. I didn't leave anything on, it was random. I jumped it with two cars and got it running, it was showing just a hair over 14V while going down the road, so it should have been charging the batteries. The truck started fine after that, until I let it sit for a few days. Then it was a bit of a labored start, but it did catch on its own. That was this morning.

And now a new symptom from today. While going down the road, the GP light illuminated several times for a second or two at a time. I don't want to drive it until I can figure this out, so that I don't mushroom a GP in the head. They are the Duratherm GP's I think.

It also fired the GP's the other day, on start-up, after driving for 30 minutes and letting it sit for 5 or so. The coolant temp was still close to 210 when I started it... so I thought that was wierd...

Could this be a bad controller? Any other ideas?

__________________
==================================================
1993 Chevy K3500 CCLB Dually, 6.5TD, 4L80e, 4WD on Alcoa's with 265/70R19.5's. 4" Tough Country lift, forged lower arms
NAPA pre-filter, Raptor 100 GPH LP, OPS realy mod, Lube Specialists oil cooler kit, Glow Shift boost and supply fuel pressure gauges, 3" stainless DP, 4" stainless turbo back, 2.25" stainless crossover, all new hardlines underneith, and a 14 bolt full floater out of a Krispy Kreme delivery van

Last edited by SickSpeedMonte; 11-24-2012 at 09:27 AM.
Offline  
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 11-24-2012, 09:57 AM   #2 (permalink)
JMJNet
Diesel Legend
 
JMJNet's Avatar
 
Join Date: Feb 2006
Location: Richardson, TX
Posts: 17,282
iTrader Score: 0 reviews

The Suburban Club Member

Probably bad controller. The contact in there can wear out, there is a picture here of TD tearing apart a GP controller/relay.

__________________
1995 GMC Suburban:
PMD in Bumper
Leroy Diesel Flight System PMD
Leroy Diesel Oil Cooler Line
4" Warpspeed Exhaust
Kennedy Diesel LP/OPS Harness
Bosch Duraterm GP
Heath Turbo-Master
AD244 Alternator
Offline   Reply With Quote Quick reply to this message
Old 11-24-2012, 12:09 PM   #3 (permalink)
heymccall
Diesel Elite
 
heymccall's Avatar
 
Join Date: Feb 2005
Location: Butler county, PA USA
Posts: 17,728
iTrader Score: 0 reviews

When I lost a rectifier diode in my '82 6.2 (with a 10SI alternator), the glow plugs would cycle while driving. (There are 6 rectifier diodes in there and one failed open on me). It would still charge the battery. Changed the bad part in the alternator, and the problem went away.
__________________
Brian
'13 Hyundai Genesis Coupe handshaker
'14 Peterbilt 337 handshaker
Quote:
Originally Posted by GetSome8.1HD
Its not like I said I enjoyed reading Good Housekeeping while taking a candle lit bubble bath then proceeding to using a loofah with exfoliating creams all while thinking about you . Now THAT would be creepy
Member #21 of the OiO association
Offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 11-24-2012, 06:20 PM   #4 (permalink)
JMJNet
Diesel Legend
 
JMJNet's Avatar
 
Join Date: Feb 2006
Location: Richardson, TX
Posts: 17,282
iTrader Score: 0 reviews

The Suburban Club Member

I did not see the alt issue, do you have the tach going haywire? If so, that is the sign of bad alt.

It may just be weak. My bad alt last me around 6 months before it went completely out.

You can see if you can figure out what Heymccall suggested.
__________________
1995 GMC Suburban:
PMD in Bumper
Leroy Diesel Flight System PMD
Leroy Diesel Oil Cooler Line
4" Warpspeed Exhaust
Kennedy Diesel LP/OPS Harness
Bosch Duraterm GP
Heath Turbo-Master
AD244 Alternator

Last edited by JMJNet; 11-24-2012 at 06:21 PM.
Offline   Reply With Quote Quick reply to this message
Old 11-24-2012, 07:02 PM   #5 (permalink)
57diesel
Diesel Veteran
 
Join Date: Mar 2012
Location: St. Paul/Minneapolis MN USA
Posts: 5,374
iTrader Score: 0 reviews

I was thinking power hiccup too. How does the wiring in this truck look in general?
__________________
98 Burb K25 4.10's 250K miles, new to me, pretty clean and stock.
95 Burb K25 3.73's CRASHED 250K miles, looks to have been rebuilt at least once, stock, bad rust, DE exhaust w/walker muffler, 8' western plow.
81 Buick Riviera GAVE AWAY with the infamous Olds 5.7 diesel possibly still going strong.
15 VW Golf wagon, TDI. Did the buyback on my 13 Jetta TDI wagon so it was basically a trade up.
96 Burb K25 3.42's SOLD at 340K miles, told it was all original, close race between engine wearing out or body completely rust out.
Offline   Reply With Quote Quick reply to this message
Old 11-24-2012, 07:06 PM   #6 (permalink)
SickSpeedMonte
Glow Plug
 
SickSpeedMonte's Avatar
 
Join Date: Oct 2010
Posts: 290
iTrader Score: 0 reviews

There was a good bit of corrosion on this truck, so it could be wiring related.

How do I check the rectifier diode? That would seem to tie the hard-start problem in with the glow plugs firing while driving problem. It would still leave the problem where they don't want to fire when I first start it, it seems.

Thanks for the tips!
__________________
==================================================
1993 Chevy K3500 CCLB Dually, 6.5TD, 4L80e, 4WD on Alcoa's with 265/70R19.5's. 4" Tough Country lift, forged lower arms
NAPA pre-filter, Raptor 100 GPH LP, OPS realy mod, Lube Specialists oil cooler kit, Glow Shift boost and supply fuel pressure gauges, 3" stainless DP, 4" stainless turbo back, 2.25" stainless crossover, all new hardlines underneith, and a 14 bolt full floater out of a Krispy Kreme delivery van
Offline   Reply With Quote Quick reply to this message
Old 11-24-2012, 08:14 PM   #7 (permalink)
57diesel
Diesel Veteran
 
Join Date: Mar 2012
Location: St. Paul/Minneapolis MN USA
Posts: 5,374
iTrader Score: 0 reviews

I have never seen a good explanation of exactly how the controller works but when it first sees power on one of the pins in the small connector it is supposed to cycle the plugs unless something (a temp sensor on the pre 96 or the ECU on post?) tells it not to. So I am thinking that its possible that its getting intermittent signal and that is why it sometimes comes on when it should not and not when it should? Just a theory. I dont have any detailed info on a 93 otherwise I would try to give you the pin outs to maybe investigate that side of things.
__________________
98 Burb K25 4.10's 250K miles, new to me, pretty clean and stock.
95 Burb K25 3.73's CRASHED 250K miles, looks to have been rebuilt at least once, stock, bad rust, DE exhaust w/walker muffler, 8' western plow.
81 Buick Riviera GAVE AWAY with the infamous Olds 5.7 diesel possibly still going strong.
15 VW Golf wagon, TDI. Did the buyback on my 13 Jetta TDI wagon so it was basically a trade up.
96 Burb K25 3.42's SOLD at 340K miles, told it was all original, close race between engine wearing out or body completely rust out.
Offline   Reply With Quote Quick reply to this message
Old 11-24-2012, 10:26 PM   #8 (permalink)
JMJNet
Diesel Legend
 
JMJNet's Avatar
 
Join Date: Feb 2006
Location: Richardson, TX
Posts: 17,282
iTrader Score: 0 reviews

The Suburban Club Member

You need to clean all the electrical corrosion and change the cable/connector as necessary first.

There is a recent thread on this about the importance of ground.
__________________
1995 GMC Suburban:
PMD in Bumper
Leroy Diesel Flight System PMD
Leroy Diesel Oil Cooler Line
4" Warpspeed Exhaust
Kennedy Diesel LP/OPS Harness
Bosch Duraterm GP
Heath Turbo-Master
AD244 Alternator
Offline   Reply With Quote Quick reply to this message
Old 12-03-2012, 12:25 PM   #9 (permalink)
SickSpeedMonte
Glow Plug
 
SickSpeedMonte's Avatar
 
Join Date: Oct 2010
Posts: 290
iTrader Score: 0 reviews

The corrosion on the wiring isn't bad, after checking it out. It was all pretty low (the corrosion) probably from being a plow truck for 2 years, and pretty much limited to the heavy metals like the frame/suspension.

Just wanted to update this thread, I think I figured out the problem *knock on wood*.

I took the GP controller out Saturday night and took it apart. It turns out that all 4 pins were a bit loose at their soldered connections to the PCB. The solder had cracked and was probably providing a good bit of resistance. I re-soldered the connections and now the GP light comes on when it should, and stays off when it should. Or at least it has the 4-5 times I've driven it since the fix.
__________________
==================================================
1993 Chevy K3500 CCLB Dually, 6.5TD, 4L80e, 4WD on Alcoa's with 265/70R19.5's. 4" Tough Country lift, forged lower arms
NAPA pre-filter, Raptor 100 GPH LP, OPS realy mod, Lube Specialists oil cooler kit, Glow Shift boost and supply fuel pressure gauges, 3" stainless DP, 4" stainless turbo back, 2.25" stainless crossover, all new hardlines underneith, and a 14 bolt full floater out of a Krispy Kreme delivery van
Offline   Reply With Quote Quick reply to this message
Old 12-08-2012, 11:26 AM   #10 (permalink)
57diesel
Diesel Veteran
 
Join Date: Mar 2012
Location: St. Paul/Minneapolis MN USA
Posts: 5,374
iTrader Score: 0 reviews

That would fit my theory that it was loosing the connection it thought you were just turning on the key and was running a normal starting cycle.

Good to know that they can be taken apart and possibly repaired.

__________________
98 Burb K25 4.10's 250K miles, new to me, pretty clean and stock.
95 Burb K25 3.73's CRASHED 250K miles, looks to have been rebuilt at least once, stock, bad rust, DE exhaust w/walker muffler, 8' western plow.
81 Buick Riviera GAVE AWAY with the infamous Olds 5.7 diesel possibly still going strong.
15 VW Golf wagon, TDI. Did the buyback on my 13 Jetta TDI wagon so it was basically a trade up.
96 Burb K25 3.42's SOLD at 340K miles, told it was all original, close race between engine wearing out or body completely rust out.
Offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Diesel Place : Chevrolet and GMC Diesel Truck Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

PLEASE READ! You must check your email inbox for the confirmation link to complete registration. Please check your spam box if you do not see the email in your inbox.

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:
Insurance
Please select your insurance company (Optional)

Log-in


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
Glow plugs fire intermittently ooshnew 6.2L Diesel Engine 16 05-06-2012 10:12 AM
Help.. HID's wont fire up ajmac Electrical 2 11-04-2008 08:47 PM
95 , 6.5 TD wont fire . thunderwand 6.5L Diesel Engine 11 12-14-2005 07:14 PM
02 cranks but wont fire 02 d-maxer Duramax First Generation: 2001-2004 (LB7) 3 04-05-2005 12:50 PM
my 6.9L wont fire...errrr 86f2504x4 Any Other Vehicles 8 02-09-2004 08:34 PM


All times are GMT -4. The time now is 08:30 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Shoutbox provided by vBShout v6.2.1 (Lite) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
© AutoGuide