cgfen

I'm having a "strange" problem.
I can not get the starter motor to crank when i turn the key to START position.
It may be a bad starter or bad starter cable connection, but i suspect it's an immobiliser/ drive block issue?
When i try my typical start procedure;

• key in
• doors closed
• key on just far enough to activate immobilizer light in clock
• press key fob button
• immobiliser light goes off
• turn to START

The starter motor does not actuate, no chug, no whir, no click, no noise at all.

I've also tried

• key in
• doors closed
• press key fob button, door locks cycle to locked, turn signal lights flash
• press key fob button again, door locks cycle to unlocked
• immobiliser light goes off
• turn to START

The starter motor does not actuate, no chug, no whir, no click, no noise at all.


What i've tried so far;

• another key fob / key combination = no change
• cleaned all under the front boot battery / ground wire connections = no change
• swapped out relay #61(Streather's book mentions that this relay is part of the "anti-drive away system") in the main under boot fuse / relay panel = no change.
• installed a fresh battery in the fob = no change
• opened / closed all door and lids to ensure they are secure.

The car runs fine if bump-started, so it's not a DME relay issue.

This occurred immediately after i installed a different set of wheels, which i accomplished by raising the car one side at a time using the rear jack points. I've done this dozens of times in the past, but i guess it's possible i stressed a starter motor hot or ground connections somehow, (not likely).

The door locks do cycle correctly when using the switch in the center console, or when the key is out of the ignition and the fob button is pressed.

i've cycled the locks using the key in the driver door lock cylinder

I've tried wiggling the key (both keys), when turning to START to try and ensure good ignition switch cylinder contact.

My car is a 96, so no clutch position micro-switch.

I've read through dozens of threads on this subject, lottsa pain-and-suffering, but little clear guidance.

Next steps;
Ask here for help.
Lift the car and inspect starter motor connections

Advice or suggestions appreciated. I really don't want to change a starter unless i'm very sure that's the problem.

Thanks

Craig

shadow993

I had this issue, but after one bump start, the problem was solved. Mine happened after a track event. I wonder if the wires get stretched

cgfen

hmmmmmmmmm
i'm actually wondering IF this could be a drive block issue, since the car runs fine when bump started.
Does anyone know if drive block prevents engine RUN, or just engine START?

Craig

cosmic_993

still could be faulty ignition switch.

e9stibi

This is what I posted recently whne I experienced similar issues:

I had starter issues and finally diagnosed it correctly: in my case it was the starter but I could rule out a lot by just making proper measurements:

http://forums.rennlist.com/rennforum...oot-cause.html

Just for the benefit of the great forum I want to add some details to the trouble shooting:

0. Swap DME relay with the spare I had in the glove box. Car did not give a single sound while starting -> rule out DME relay issue at the moment
1. Battery voltage 12.8 V and I switched it with the one from my second (starting) 993. Still no cranking or klicking from the solenoid -> battery ok
2. All connection at battery tight and mass band in trunk "looks like new" -> ruled out issues here at the moment
3. Switched Starter relay (R61) with a similar relay that knowingly works (e.g. horn that is easy to test). car still "dead while starting -> starter relay R61 ok
4. Pull starter relay R 61 and do the following measurements:
4.a Check pin 86 for 12V. This is the 12V from the immobilizer to the starter relay coil that acts as an interlock to start the car. In my case I got the 12 V when I opened the car properly and turned the ignition on within the required time. -> immobilizer ruled out as an issue
4.b. Check pin 85 for proper mass signal (resistance measurement against mass). MJ 97 and later have a clutch switch that provides the mass to the starter coil switch. I measured "0 Ohm" with depressed clutch -> ruled out clutch switch

The previous measurements confirmed that the starter relay coil gets the proper supply. No to the power side of R61

4.c. Check pin 30 for 12V with the ignition switch turned to position 3 (start position to crank). I measured 12 V. -> ruled out ignition switch issue

The previous measurement confirmed that the power side of the R61 gets the proper signal too (12V). This all ruled out any relay related issues "in the trunk". I than moved to the starter and its connections as I assumed that an issue with the cable that provides the switched 12 V from starter relay power side to the starter solenoid is not likely.

5. Checked starter for tight and clean connections. Need to include the mass connection at the chassis side -> everthing was thight and clean like new -> IT MUST BE THE STARTER

6. Replaced starter -> car starts as it is suppsed to start!

Bottomline is as Steve already said: Root causes can be multiple and proper and "cheap" diagnosis before replacing expensive parts like Immobilizer unit can safe both time and money.

Here is the list of potential issues again that can lead to a car not starting "from the electrical side" and I am sure there is more when you include general "cable issues" between working components.

1. DME relay
2. Battery
3. Battery connections
4. Starter Relay R61
5. Immobilizer Unit / maybe key fob if you are lucky
6. Clutch switch (for MJ 97 and 98)
7. Ignition switch
8. Connections to starter
9. starter itself

Good Luck!

cgfen

Thanks. I appreciate you taking the time to post.
We think alike
I've tried / done everything you've listed with the exception of 4A and 4C.
I'll measure VDC there prior to ordering a starter.

Please check the link you posted, it did not work for me, got a 404 error.

cheers

Craig

cgfen

4A and 4C behave as you indicate.
off to the new starter store..............................

Thanks again.

e9stibi

I got a new Bosch starter for about 260 USD. If interested in the details shoot me a PM and I will check the supplier.

Kika

I had it happen on my SC at the Track. mechanic there said it was likely due to the heat, and expansion of the metals, making the starter stick. It worked fine cold, but hot, it would not be able to engage. hitting it with a hammer helped, but ultimately putting a new one in solved the problem.

IXLR8

Since you are going to remove it, at least do a bench test first.

Tap the started with a plastic tipped hammer. Stuck/worn/short brushes?

They can be rebuilt.

jg291446

Cgfen, how did you solve the problem?

cgfen

It wasn't the starter or a starter connection.
Tony Callas recommended that I replace the "start relay", not exactly sure of the name after all these years, but it was in the main relay box in the front trunk and DEFINITELY NOT the DME relay.
I think i just swapped a few similar relays spot to spot and the problem never resurfaced.

Craig

Railmaster.

Had the same problem with an old Volvo today.

If it was the DME relay, the car would crank but nog fire, but on Rennlist it's ALWAYS the DME relay...

There is a thin wire entering the starter motor, after i removed the wire and polished the contact surfaces and put the wire back again the car started.