Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 924/944/968 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
elvisizer's Avatar
 
Join Date: Nov 2003
Location: sf, ca
Posts: 5
Unhappy icu replaced, now the S won't start at all . . . .

My '87 S was having ignition problems recently- the engine would cut out momentarily sometimes, even under WOT. I stopped driving the car and ordered a replacement ICU (ignition control unit) on the advice of rennlisters. So, the car stayed parked for about a week until the ICU showed up. I took the old ICU out, and put the new one in. Now the car won't start at all. It turns over, and I can eventually smell fuel, so the DME relay is functioning, but the engine never fires. It does cough a bit now and then, but it never even comes close to firing up. Which is strange, because even when it was having the ignition problem, it still always started on the first try. I did try putting the old ICU back in, but got the same results as with the new one.
Now, I'm kinda worried i might've messed up the plug that connects to the ICU- is there anyway to check if i have? It was REALLY hard to get the plug off of the old ICU, and i think some retaining tabs on the plug may have been torn off . . To check if it was a loose connection causing this, I tried wiggling the plug around on the ICU while a friend turned it over, but there didn't seem to be any relationship between the splutters and any particular position of the plug. . . Any advice on what I could try next?
thanks in advance . . . . .
elvisizer


Last edited by elvisizer; 11-20-2003 at 04:46 PM..
Old 11-20-2003, 04:43 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Moderator
 
AFJuvat's Avatar
 
Join Date: Feb 2001
Location: Viera FL
Posts: 5,643
Well, what did you try before swapping the DME (ICU)? It is also entirely possible that the new DME is bad as well - put the old one back in and see what happens.

AFJuvat
__________________
Es geht nicht darum wie schnell man faehrt, sondern wie gut man schnell fahren kann.

Ihr Brunnen der nutzlosen Porsche Information
Old 11-20-2003, 05:57 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
Mike, He must have a 944S as this is the ignition control unit that mounts on the fender and interfaces the DME to the coil.

Me thinks that the connections are whacked.
__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 11-20-2003, 07:56 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
elvisizer's Avatar
 
Join Date: Nov 2003
Location: sf, ca
Posts: 5
Quote:
Originally posted by AFJuvat
Well, what did you try before swapping the DME (ICU)? It is also entirely possible that the new DME is bad as well - put the old one back in and see what happens.

AFJuvat
I did put the old ICU back in- same results as with the new one . . . . won't start at all. which makes me think it's now a wiring problem, since it used to start with the old one- it just wouldn't run very well. but it did start.
elv
Old 11-21-2003, 08:48 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
Could also be an alarm problem.
__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 11-21-2003, 11:47 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Nov 2003
Location: Littleton, CO
Posts: 78
Are you getting spark?? It is not unheard of for coils to fail on these cars and it could be a coincidence that it failed completely when you switched the DMEs. Also, without the tabs on the DME connector it's possible you could have pushed a couple of the connectors out of the plug.

Good Luck!

Pat
__________________
87 944S Black/Black Club Racer
87 944 Kalahari Beige/Brown Daily Driver
82 911SC Platinum Metallic/ Brown Garage Queen
Old 11-21-2003, 12:04 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered User
 
elvisizer's Avatar
 
Join Date: Nov 2003
Location: sf, ca
Posts: 5
no dme's involved here- this is on an S, so i'm talking about the ignition control unit that's just below the coolant reservoir on the driver's side front wheel well.
pm9146- i'd like to check that, but i'm not sure how to get the spark plug connector off the plug . . . . Can you tell this is my first attempt at working on the S?? anyway, do i just pull it off? I gave one an exploratory tug, and it didn't seem to want to come off. . . . .

Last edited by elvisizer; 11-21-2003 at 02:00 PM..
Old 11-21-2003, 01:53 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Mar 2003
Location: West Haven, Connecticut
Posts: 812
Send a message via AIM to TheCooler
Pull.
__________________
-2002.5 GTI VR6 24V 6SPD
-Kalahari Beige 89 Porsche 944S2
-87 VW GTI 1.8 16v
-2007 Ford PIMP(free)star ...company car....
-1999.5 Jetta VR6
Old 11-21-2003, 02:03 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered User
 
elvisizer's Avatar
 
Join Date: Nov 2003
Location: sf, ca
Posts: 5
thanx, cooler. i'll pull harder when i get home from work . . . .
Old 11-21-2003, 02:22 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
Take the ground off of the battery for about 20 minutes. Supposed to reset the DME. Yes I know you replaced the ICU but try this anyway.
__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 11-21-2003, 04:16 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered User
 
elvisizer's Avatar
 
Join Date: Nov 2003
Location: sf, ca
Posts: 5
i'm pretty sure the DME is functioning since i can smell fuel after a few seconds of cranking the engine, but i'll give such an easy fix a try anytime . . . .
thanx, socal . . . . .
elvisizer
Old 11-21-2003, 04:35 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
The power to the ICS Ignition Control Stage and to the coil come from the same pin on the connector in the engine compartment.

This goes to pin #4 on the ICS and connection #15 on the coil.

Both wires look like they are black.

The ICS has a green wire that goes to the other pin on the coil. This is the "trigger" wire to fire the coil. Both connections are on pins #1.

The sheilded trigger wire from the DME goes to pin #5 on the ICS.

Pin #2 on the ICS goes to ground.

So with the key on you should be getting 12 VDC on pin #4 on the ICS and connection #15 on the coil.

Just a though have you checked that the HV wire from the coil to the dist cap is intact? Not pulled off of the connectors inside the weather boots?

__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 11-21-2003, 06:12 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 08:11 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2020 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.