Car wont start, Help solve please.

[Benny771]

Was driving home for approx. 1 hr when the engine just stopped. Managed to pull over to the side of the road. Car started then drove for approx. 1 min. Sat at the side of the road for an hour, car started and ran for approx 20 min.
Then dead. both times there was a fuel explosion out of the tail pipe approx. 10 sec after it died.
It would not start again....
Tow truck was happy to take 400$.

Question is: Do you think i should look at the coil first, then?????

I will fill you in as i go but any help would be appreciated.

P.S i can still hear the fuel pumps humming away. Both.

P.S.S no spark at the wire or from the coil?...................... Bad coil.... i hope?

Tested the coil + and - . Zero voltage while cranking. Looks like the coil is good?

[kodioneill]

Need to know the year and model and mileage.

[Benny771]

Originally Posted by kodioneill

Need to know the year and model and mileage.

Sorry year, 1989 Model 930, mileage, 100 000 miles? Possible rebuild by previous owner.

[Mattcamp]

DME Relay

[kodioneill]

AS Mattcamp stated the DME relay is a common suspect. The relay is located under the driver seat next to the Motronic box. It powers the controls for Fuel injection and ignition.

[Benny771]

I took the seat out and the relay does not look like the one in the picture for sale here on Pelican?
I got 2 part #'s one for each.... (on the square boxes under the drivers seat)
930 618 123 00
930 617 131 02

But if i search i find this one?
Pelican Parts - Product Information: 911-618-154-00-M252

[Benny771]

Which one should i order as a spare?

S


They dont look like the one that pelican has?

Pelican Parts - Product Information: 911-618-154-00-M252

[kodioneill]

That doesn't look like a motronic car!
I think that's a Lambda box.
can you post a photo of your engine?

[Vin-barrett]

he has an 89 930, not 911
It has CIS, no DME

[kodioneill]

Im not versed in 930 cars, but if they have a similar ignition system as a SC I would suspect the hall effect unit in the distributor has a intermittent open in the coil. Check the distributer wire and the coil for spec with a VOM. Again I am not familiar whit these models.

[Benny771]

As requested

[kodioneill]

There is no power to the coil until a signal is sent by the distributor. I would suspect the coil for sure they can be intermittent and it is not uncommon for them to fail. Not very expensive either!

[Benny771]

Originally Posted by kodioneill

There is no power to the coil until a signal is sent by the distributor. I would suspect the coil for sure they can be intermittent and it is not uncommon for them to fail. Not very expensive either!

Coil was tested at the pos and neg leads with a meter while cranking and ignition on.
I have no voltage.

[kodioneill]

I'm talking about the hall effect coil in the distributor. It sends a signal to the cd box and in turn the box sends voltage to the ignition coil at the time it should fire. Can you hear the cd box whine with the key on? Just a side note check the fuses under the panel on the left side of the engine compartment make sure they are snug and clean.

[Benny771]

Yes i have the cdi box whine.
And still cant find the DME relay.... Pelican parts does have one for this car, But where!!!!

[rick-l]

1. The CDI (Capacitive Discharge Ignition) has no DME relay
2. The coil in a CDI is a transformer that boosts the 400 volts stored on the capacitor 1:100 to 40,000. There is no measurable voltage (<<12 V)across the coil until the SCR is triggered.
3. It is not a Hall effect sensor it is a variable reluctance sensor and the output (small current) follows the green wire.

[Staylo]

No DME on a 930.

My $.02 says bad VR.

[kodioneill]

Hall effect - Wikipedia, the free encyclopedia

[Benny771]

Originally Posted by rick-l

1. The CDI (Capacitive Discharge Ignition) has no DME relay
2. The coil in a CDI is a transformer that boosts the 400 volts stored on the capacitor 1:100 to 40,000. There is no measurable voltage (<<12 V)across the coil until the SCR is triggered.
3. It is not a Hall effect sensor it is a variable reluctance sensor and the output (small current) follows the green wire.

What is a SCR and what triggers it?

I tried a new coil (generic) but it was still a no fire.
Coil in the distributor? I dont know how to test this, and where does the green wire go?

[rick-l]

You are sure there is no spark? How familiar are you with electronics?
6-pin SC/Turbo CDI unit repair documentation

Here is more theory of operation
History of Bosch CDI ... toubleshooting info, parts list changes, and schematics ...

Maybe someone will chime in with typical failures if you need to shotgun cheaper parts.