 Help with Carerra no start |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
| 914ltd |
 Aug 1 2011, 02:09 PM
Post
#1
|
|
Member  Group: Members Posts: 243 Joined: 18-April 03 From: Peoria, IL Member No.: 581 Region Association: None 
 |
Hi guys, I have an 84 Carerra in my shop (OK, it's not a 914 but there's more talent here than some other forums) with an intermittent no start. The car has no spark then will start and run fine. I have checked the DME and coil connections but nothing else. It is getting fuel smell at the exhaust during no start. Anyone know of a condition that might cause this? Thanks, Brad Mayeur
|
   |
 
|
  |
Replies
| r_towle |
Aug 1 2011, 03:33 PM
Post
#2
|
|
Custom Member Group: Members Posts: 24,638 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States
|
dme relay, cht, grounds grounds grounds.
Cap and rotor also...but I assume you checked that. Coil also. The DME relay was made when they were doing a crappy type of soldering....so was the DME itself. There are pics on Pelican of all the bad solder joints in both the relay and the DME that cause all sorts of weird conditions. If you look at the backside of many of the boards from that era of german cars you will see a discoloration and ring around the post of the resistor, capacitor etc. That ring is a break in the solder and when it gets hot, its stops contact...when cold its fine. Lovely thing to track down, but if you look at enough you can learn to see if with a magnifying glass pretty quickly. It takes ten seconds to fix them....just reheat. I did all the ones on the BMW Lights computer...took about 5 minutes...all problems gone. I just re-solders all of them (acutally had a friend do it who is really good at soldering) Its a common issue. The ignition is controlled by the DME so start there. There are a number of tests that you can do with an Ohm meter at the DME plug to help you diagnose the wiring, I suggest you may want to do that first. There are breakout boxes to test the car live while running to diagnose all the other bits, but the CHT is a simple one to do at the plug in the engine bay (provided the wiring tests out good) Those tests are in the factory manuals and in the Bentley manual also. There is a good flow chart in the bentley for "no ignition" Grounds seem to solve alot just by ensuring that certain circuits do not heat up. Steve Wong has alot of articles on the DME and Carrera FI system. I think its www.911chips.com. Rich |
|
|
|
Posts in this topic
914ltd Help with Carerra no start Aug 1 2011, 02:09 PM
Ferg DME Relay?
http://forums.pelicanparts.com/porsche... Aug 1 2011, 02:19 PM
pcar916
DME Relay?
That's always my first thought. ... Aug 1 2011, 02:30 PM ConeDodger The DME relay would be my first guess. They usuall... Aug 1 2011, 02:51 PM phatnine11 The CHT sensor! This sensor gives off very str... Aug 1 2011, 02:57 PM scotty b Order of most likely :
DME relay
CDI If it has b... Aug 1 2011, 03:14 PM Cap'n Krusty Carreras with Motronic don't have CDI boxes.
... Aug 1 2011, 03:25 PM 914ltd Thanks guys, I thought the DME relay controlled th... Aug 1 2011, 08:32 PM |
3 User(s) are reading this topic (3 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 31st October 2024 - 07:29 PM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.