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

[iceman]

If you are dead positive you have no spark (I don't know what you are doing to test it besides the multimeter on the coil), the pump shouldn't be running either and I think you said you had no fuel coming out of the regulator? This means the ecu is not getting coolant temp or crank position. I think on an m20 it may need afm signal too.

No the idle control valve is not part of the spark, but it is the air. If the valve is stuck, the car won't start. It is easy enough to check on an m20.

[ST1G]

I don't think anyone told you to clean the idle control valve? I was in the same situation and that was my fix. It is good one for hard/no starts with cranking and would explain why it starting correlated to you blipping the throttle.

But it would not explain no spark. It's not an intricate part of the ignition system from my understanding.

[iceman]

I don't think anyone told you to clean the idle control valve? I was in the same situation and that was my fix. It is a likely culprit for crank no start.

Don't give up, you can figure it out.

Here is my basic checklist, sorry if something is redundant.

(1) Sensors/ecu stuff critical to starting:
coolant temp
crank sensor and its reference markings (you checked that)
afm
idle control valve

(2) Fuel
Is the pump running while you are cranking the engine? Fuel should be coming out of the regulator or the feed hose while you crank the engine. You could also jump the pump by pulling the relay and using a piece of wire, it is in a group of three in front of the fuse box.

(3)Air
Look for large vacuum leaks

(4) Ground wires, there is one from the engine to chassis, one under the back seat (for the pump I think...), one under the dash, and on the m20b27 under the intake manifold for the ecu, idk where it is for the b25.

(5)Clean and dry ignition stuff, but you did that.

[ThatOneEuroE30]

Car cranking, but not starting

Seriously . That's how I feel. The only thing I've ever tried to do that's more complicated than this is mega squirt.

Just yank the pos and throw in a m50 do a budget swap.

[ST1G]

This is getting fucking confusing. I'd be like

Seriously . That's how I feel. The only thing I've ever tried to do that's more complicated than this is mega squirt.

[ThatOneEuroE30]

This is getting fucking confusing. I'd be like

[ST1G]

Guess what guise. NO SPARK.

So, I put in the new CPS, got it in there, got her all situated. No spark.

Then I get to testing. I decide to put the multi meter on the coil positive (pin 15), and ground (body) and I'm getting 192Ω I get the same 192Ω when I put the meter between the negative terminal (pin 1) and ground (body) This was with the ignition on. This still doesn't make sense to me, since if the positive is grounded then the coil wouldn't get the signal to send spark.

After a few attempts to get the car to spark with nothing I checked the coil again and now I get a millisecond of continuity between pin 15 on the coil and ground and then it goes to infinite resistance (open). Same with the negative.

I then tried the coil from my running car. Same thing with the moment of continuity. No spark.


I don't even know any more.

[HennaE30]

I snagged a new CPS tonight. It was $50 so I pulled the trigger. I plugged it in and checked pins 46 & 47 on the DME harness and now I have 50 more Ohms. So that's a good sign :D I'm going to get it all the way installed and gapped right and see what happens. I hope this is it.

Good luck! Hoping for you that it works out.

[ThatOneEuroE30]

I snagged a new CPS tonight. It was $50 so I pulled the trigger. I plugged it in and checked pins 46 & 47 on the DME harness and now I have 50 more Ohms. So that's a good sign :D I'm going to get it all the way installed and gapped right and see what happens. I hope this is it.

Let's hope! Possible to have it started by the end of the night

[ST1G]

I snagged a new CPS tonight. It was $50 so I pulled the trigger. I plugged it in and checked pins 46 & 47 on the DME harness and now I have 50 more Ohms. So that's a good sign :D I'm going to get it all the way installed and gapped right and see what happens. I hope this is it.

[ThatOneEuroE30]

Yea do that for sure

[ST1G]

I'd pony up and buy a new CPS so you can be 100% it's not that.

Yeah, that's what I gotta do I think. I'm going to go talk to the parts guy at at Import Parts Specialist, he is a wizard when it comes to e30s and owns a few. I guess if it doesn't fix it I could return it too.

I know you mentioned this started as an intermittent problem but I would check the fusible link as well. Is your ECU getting power?

From what I've read it definitely points to either a bad ground, main relay, DME, CPS or bad harness.

Good luck

Again, post 66 eliminates a bad ground, main relay, DME, harness. I also stated in post 56 and 41 that my DME worked in a friends car, and his didn't work in mine, thus eliminating the DME.

[EyExR]

I know you mentioned this started as an intermittent problem but I would check the fusible link as well. Is your ECU getting power?

From what I've read it definitely points to either a bad ground, main relay, DME, CPS or bad harness.

Good luck

[ThatOneEuroE30]

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

How do I measure the engine rpms with the multi meter?

Yea how do you do that? I'd pony up and buy a new CPS so you can be 100% it's not that.

[ST1G]

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

How do I measure the engine rpms with the multi meter?