pa951

Well the car is at a specialist but still no luck finding the reason for the startup hickup. Just got told the ignition is off. I recently found out the dme in my car has been changed once. It no longer has a 24pin but a 28 pin dme. Could that couse the problem? Or that the dme has a wrong chip? Only on startup it occurs.

pa951

Been à while... Changed wiringloom from dme/klr Changed dme and klr, Changed rotor and sparkplugs, Changed sensors, Changed sensorholder and still no cure..

My second starter just got blown apart because of THE backslash.

We found out that when backfire happens the ref sensor gets à peak current. Only on startup.

Extra ground does not work, help.....

Changed allmost everything i can think of without THE desired normal start.

Before i get rid of THE dme by using a stand alone computer did i miss anything?

Alternator of any influance?

931guru

The clue that the ref sensor is getting a big voltage spike points back to this TSB.

There are two types of starters, one with a large diameter (in the early 944 cars) and one with a smaller diameter (in the later 944 cars and the 951s). The smaller diameter starters seem to put out a lot more stray magnetism, causing the spike in the ref sensor.

The shield on the bracket seems to help this.

pa951

Shield did not fix it..

bentrm

Hello. New member here. My buddy has a 1987 944 turbo and we're having this exact issue. I know i'm trying to revive an old thread, but have you found a fix? Thanks in advance. Gonna keep searching. Ugh...

pa951

Nope, changed just about everything that could be changed and still the hickups.

I made a radical change in my plans and replaced the computers with a stand alone ecu using a sensor on the front of the engine. Never had any problems since.

It had to have been a sensor interference of some kind.

bentrm

Thanks for the reply pa951. Especially after so long. Great forum. Gladly buy you a brew if you're in Pittsburgh!

F18Rep

I've seen this problem twice now, Search the archives for "thunk". One of mine was a open ground (the shield in the cable that goes to the ref sensor) was open due to a corroding crimp/solder at the connector on the harness side (not the sensor side). A lot of troubleshooting but an easy fix....Bruce

pa951

I Changed the wires to both sensors with new ones from lindsey racing. Then changed both sensors. Changed the complete engine wiring loom, changed wiringloom to the starter, changed wiringloom to the alternator and still had them. I just gave up after spending more then 2000€ on parts and labour.

With the new ecu and front mounted sensor no more problems.

jlturpin

There was a later speed and reference sensor bracket that had a shielded extended sheath. This could be the issue if engine or sensor mount was swapped. I.have seen it on a few cars over the years. Almost like kickback symptoms.

pa951

Also changed to the newer style bracket with shield.