Notices
924/931/944/951/968 Forum Porsche 924, 924S, 931, 944, 944S, 944S2, 951, and 968 discussion, how-to guides, and technical help. (1976-1995)
Sponsored by:
Sponsored by:

spark, fuel, compression, tach bounce but no start

Thread Tools
 
Search this Thread
 
Old 09-16-2014, 03:44 PM
  #31  
83 944
Pro
 
83 944's Avatar
 
Join Date: Jan 2009
Location: Albany, OR
Posts: 618
Received 31 Likes on 12 Posts
Default

Check your grounds. i just had a similar issue. i had a loose ground and a corroded ground on the harness to engine in the back by the sensors. not a problem yet. poor grounds can cause electrical nightmares and making you chasing a lot of other "related symptoms" .

good luck

Mike
Old 09-16-2014, 03:45 PM
  #32  
83 944
Pro
 
83 944's Avatar
 
Join Date: Jan 2009
Location: Albany, OR
Posts: 618
Received 31 Likes on 12 Posts
Default

also a bad harness ground can skew readings
Old 09-17-2014, 04:00 AM
  #33  
drive135mph
Instructor
Thread Starter
 
drive135mph's Avatar
 
Join Date: Jul 2014
Location: Lynchburg VA
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
Default

Awesome I Appreciate the responses, I will carry out those tests tomorrow morning and see if I find anything interesting

If nothing else I hope this thread serves as a good guide for owners in the community chasing fuel related non-starts.
Old 09-19-2014, 08:36 PM
  #34  
drive135mph
Instructor
Thread Starter
 
drive135mph's Avatar
 
Join Date: Jul 2014
Location: Lynchburg VA
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
Default

Update:
It's been raining like crazy but at last the Lindsey racing harness is in. No change. I also noticed that grounding either pole of the injector pigtail gives 12v on my voltmeter with the key on.

I also tested the speed and reference sensors at the DME and both volts and ohms readings were well within range on both sensors.

Tomorrow II will go through the grounds in earnest but grounding either the block or the body of the car with juper cables changed nothing so it seem to me that are not the culprit

Questions:
- Shouldn't only one side of the injector connector have 12v?
- What other possible explanation could there be for no injector pulse? The DME is known good and the harness is 6 hours old and correctly installed

Last edited by drive135mph; 09-19-2014 at 11:07 PM.
Old 09-20-2014, 04:17 PM
  #35  
drive135mph
Instructor
Thread Starter
 
drive135mph's Avatar
 
Join Date: Jul 2014
Location: Lynchburg VA
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
Default

Resolved!!!!

After adding the new harness testing everything I could imagine still no joy

I finally went over my alarm system jumper on the off off chance that there was a break in the wire I used to jump it (new wire!!!) I would make another one. I made the new jumper wires and installed them and it fired right up!!!!!

A huge thanks to everyone who posted or researched on my behalf If you are ever in Lynchburg PM me and I will gladly buy you a beer.

Mods: if you could put Resolved in the title that would be great

Last edited by drive135mph; 09-20-2014 at 09:25 PM.



Quick Reply: spark, fuel, compression, tach bounce but no start



All times are GMT -3. The time now is 01:34 PM.