Car cranking, but not starting(Now with spark!)

[solo318]

Measure the voltage at the coil while you are cranking the engine. Then use your fluke to measure engine rpms while cranking.

[HennaE30]

I see. Well the wheel look like it's functioning how it should. My sensor is mounted just like this one, except it had a 10mm bolt holding it not a 5mm allen.







The CPS I had in there was very dirty, I cleaned it and still had no luck with spark. I put in the one from the yard (from car with broken tbelt) and that's the one I did the above testes with. I'm very suspicious of the CPS. I should probably pony up and buy a new one.







See post 66

Ah my bad... Missed that one

[ST1G]

He meant the tooth wheel where the CPS is getting its signal from.

I see. Well the wheel look like it's functioning how it should. My sensor is mounted just like this one, except it had a 10mm bolt holding it not a 5mm allen.



The CPS I had in there was very dirty, I cleaned it and still had no luck with spark. I put in the one from the yard (from car with broken tbelt) and that's the one I did the above testes with. I'm very suspicious of the CPS. I should probably pony up and buy a new one.

Have you checked the harness for continuity

See post 66

[HennaE30]

Have you checked the harness for continuity

[ThatOneEuroE30]

The harmonic balancer

[dnguyen1963]

He meant the tooth wheel where the CPS is getting its signal from.

[ST1G]

From your diagnosis, it seems that your CPS is not sending the crank signal to the DME preventing the car from starting. Your engine is turning over, but the CPS is not detecting it. Measure the distance between the CPS and the tooth wheel again and make sure that it is correct.

I'll check the distance again with a feeler gauge.

Did you check the physical condition of the trigger wheel. If the bolts are loose or missing it will not give a signal. Also make sure the bracket is properly mounted.

I'm not sure what you mean by 'trigger wheel'.

[solo318]

Did you check the physical condition of the trigger wheel. If the bolts are loose or missing it will not give a signal. Also make sure the bracket is properly mounted.

[dnguyen1963]

From your diagnosis, it seems that your CPS is not sending the crank signal to the DME preventing the car from starting. Your engine is turning over, but the CPS is not detecting it. Measure the distance between the CPS and the tooth wheel again and make sure that it is correct.

[ThatOneEuroE30]

Yeah seriously. Or someone who knows what they are doing. I'll reach out to Jlevie if he doesn't respond and if no one else knows anything.

Maybe Steve, levent or Jon I think is his name(forecedfirebird) they all help me.

[ST1G]

Yea you've done all I could think of at this point. My car started after all this shit. What about talking to a forum member with a shop and get their input.

Yeah seriously. Or someone who knows what they are doing. I'll reach out to Jlevie if he doesn't respond and if no one else knows anything.

[ThatOneEuroE30]

I'm a little miffed. I think that I should get more resistance with the CPS connected in step 2. I also think that I should be getting 12.5v in the places that I'm getting 12.2v. But I'm not really sure. Maybe @Jlevie himself could lend a hand.

Yea you've done all I could think of at this point. My car started after all this shit. What about talking to a forum member with a shop and get their input.

[ST1G]

Okay, so I went through the tests in post 4 from Jlevie and this is my results. All tests were with a Fluke multi meter. Battery gives me 12.4V when I measure across it.



1) Disconnect the coil negative and check continuity from that connector to
DME pin 1. Also verify that from DME pin 1 to ground is an open circuit.

I have this.

2) Check the resistance across DME 47 & 48, which should be 500-560
ohms. If the CPS is dismounted, the resistance can be seen to change
from about 500 to 540-540 when a ferrous object is brought to the face of the
sensor. Neither pin should be grounded.


With the CPS plugged in I have 507Ω. It seems I should have 550Ω with the resistance of the CPS added in I think. When I unplug the CPS I get infinite resistance at the pins.

No grounding on either pin.

Curiously enough I don't get continuity beeping from the multimeter between the two pins.


3) Check for continuity from DME 36 to main relay 85 and from DME 3 to fuel
pump relay 85.

I have this.

Reconnect the coil, remount the CPS (air gap should be 0.040"), plug the
relays back in, reconnect the DME, and connect the battery. Then do the
following checks:

I wasn't sure how I would measure pins if the DME was plugged in, so I didn't plug it in. I tested the pins on the harness inside the car.

1) With the key off, verify that power is present at DME pin 18 and main relay
86 & 30.


I got 12.5v at pin 18.

Power at the relay locations.

2) With the key on, verify that power is present at DME pin 27 and pin
18. Power to pin 18 is from the main relay and there should be power to the
injectors and fuel pump relay.

DME pins 18 & 27 both have 12.2V



3) With the key on, verify that no voltage is present at the DME grounds (2,
14, 19, 24).

No power at any of these pins. Tested with both multi meter and test light.

4) Verify that power is present at the coil positive and at fuel pump relay
pin 30. Those get switched power from the ignition switch via C101.

Yes, I get 12.2V at the positive coil.


I'm a little miffed. I think that I should get more resistance with the CPS connected in step 2. I also think that I should be getting 12.5v in the places that I'm getting 12.2v. But I'm not really sure. Maybe @Jlevie himself could lend a hand.

[ST1G]

Srsly though.

[Farbin Kaiber]

I just realized that I've seen him before. Same with over on BF.com he seems to ALWAYS be right.

ftfy.