Go Back   Jeep Garage - Jeep Forum > Jeep Technical Discussion > Tech Tips DIY/How To

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 11-02-2013, 05:03 AM
Member
 
Join Date: Apr 2013
Posts: 9
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 384
pdiamond1941@gmail.com is on a distinguished road
WG 2.7crd 2002 gloplug timing,hard start

Cranking time to start increase with temp drop. Glow plug indicator only stays on for 3 secs instead of the manual times of +10C - wait to lamp on - 6 secs and preheat cycle (lamp on) - 21secs. Where are these timings set ? ECM and can they be altered or are they reduced in my case due to faulty part or wiring etc?

Mechanic wants to go the fuel pipe chase first.

Thanks any input

pd
__________________

__________________
Reply With Quote
  #2  
Old 11-02-2013, 10:12 AM
Frango100's Avatar
The BEAST from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 4,323
Thanks: 8
Thanked 32 Times in 31 Posts
Rep Power: 524716
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: WG 2.7crd 2002 gloplug timing,hard start

Yes, the ECM calculates the glow times depending on the coolant temperature input. See attached a table of the glow times depending on the coolant temperatures. Seems to be a coolant sensor (circuit) problem.
Attached Files
File Type: pdf glow times.pdf (83.4 KB, 3 views)
__________________

__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
Monroe Reflex shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
  #3  
Old 11-02-2013, 01:07 PM
Member
 
Join Date: Apr 2013
Posts: 9
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 384
pdiamond1941@gmail.com is on a distinguished road
Re: WG 2.7crd 2002 gloplug timing,hard start

Thanks Frank,
Does the coolant temp input use the same sensor as the temp. gauge. Mine is reading correctly. If not is there another sensor. Can the timings be changed in the ECM by a diagnostics guy.

I am dubious about a fuel lift problem. When temp is above 15C (ambient) engine starts instantly. At 10C, 25 secs of cranking is necessary. I did notice the short 3 sec glow time which seems inadequate compared to the manual glow lamp times. The engine starts instantly all day after first start - so glow plugs time or fuel lift ?
Many thanks
PDIAMOND
__________________
Reply With Quote
  #4  
Old 11-03-2013, 10:42 AM
Frango100's Avatar
The BEAST from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 4,323
Thanks: 8
Thanked 32 Times in 31 Posts
Rep Power: 524716
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: WG 2.7crd 2002 gloplug timing,hard start

Don´t know the crd very well, but from my understanding there is only one coolant temp sensor.
Eventhough the temperature indication is ok at operating temperature, you don´t know this for when its cold. The indicator starts with 40 °C when i´m not wrong.
I will see if i can find any resistance values for this sensor, so that you can check that. I doubt if there is any possibility of flashing the ECM with other glow times.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
Monroe Reflex shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
  #5  
Old 11-03-2013, 11:07 AM
Frango100's Avatar
The BEAST from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 4,323
Thanks: 8
Thanked 32 Times in 31 Posts
Rep Power: 524716
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: WG 2.7crd 2002 gloplug timing,hard start

I found a resistance chart for the petrol engine coolant sensor (and inlet temp sensor) and i believe it should be the same for the crd. Also check the inlet temperature sensor at this ocassion, because that one is also used for the glow timing.
Attached Images
File Type: jpg CoolantandAirTempChart.jpg (35.8 KB, 5 views)
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
Monroe Reflex shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
Reply

Thread Tools
Display Modes

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
2002 Grand Cherokee 2.7crd auto mossberg Grand Cherokee - WJ 1 02-10-2013 10:31 PM
Occasional hard-start condition dr.lee.baugh Grand Cherokee - WK 2 06-20-2011 06:38 AM
9 deg outside wj hard start violant00 Engine Performance/Intake/Exhaust 34 01-28-2011 12:55 AM
WJ Hard start when hot Jeep95XJ Engine Performance/Intake/Exhaust 7 08-22-2010 11:19 PM
Hard to Start '04 Grand Cherokee bbd1012 Engine Performance/Intake/Exhaust 1 07-14-2010 11:24 AM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 05:37 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community