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

[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.

[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]

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.

[iceman]

Has the car always had a manual transmission?

[ST1G]

If you are dead positive you have no spark (I don't know what you are doing to test it), the pump shouldn't be running either. 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.

I'm testing spark in a garage with no windows at night, I would see even the faintest spark. My Method of producing spark works fine on my other m20 e30 with the same coil, wire, and plug.

I don't hear the fuel pump running either. Coolant temp and afm are not mentioned in the Bentley as required for ignition.

Right now my main focus is getting spark. It's step two in an engine firing. Once I get spark I'll move onto fuel.

[ST1G]

Has the car always had a manual transmission?

According to the vin decoder it has.

[iceman]

The ecu tells the pump to turn on. The ecu also turns the coil on. They should happen at the same time. If the fuel is turning on and the spark is not there, it tells you the ecu has what it needs and your fault is somewhere in the ignition. If the spark and fuel is not there you know the ecu is not getting what it needs.

The fuel pump running will tell you the crank sensor is working.

[EyExR]

I'd go through the list again and double check everything. Make sure all sensor clips are well seated and the C191 connector under your manifold is nice and snug with no loose or fouled wires. And check for continuity at the fusible link.

[solo318]

Look guys. Ignore everything else until you get spark. The spark is triggered directly from the CPS and is the first thing that comes live when the ecu sees engine rotation. Stop with the random guessing about fuel and air shit. Lets get the spark problem figured out.
Most fluke meters have an RPM setting if yours does not than you will need to measure a/c voltage at the cps connector with the connector unplugged. Make sure you have a reasonable amount of voltage. What is the cranking voltage of the car (while the starter is engaged).

[solo318]

The other thing that I meant to ask is if you have an aftermarket alarm or tach in the car.
Either of these would tie into the coil trigger wire.

[HennaE30]

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

[2002tiiguy]

Stupid question, did you check fuses?

[2002tiiguy]

Also, take a test light and clip it to positive and negative on the coil, see if it blinks when you crank it

[ST1G]

Stop with the random guessing about fuel and air shit. Lets get the spark problem figured out.

This time 1000

I really appreciate the help from everyone, but it's frustrating when you post before reading, and are tossing out an idea that has already been tested and ruled out.

The other thing that I meant to ask is if you have an aftermarket alarm or tach in the car.
Either of these would tie into the coil trigger wire.

I have a euro clock installed. But the car will run even without a cluster in, IIRC.

Stupid question, did you check fuses?

Again, post 66.

[2002tiiguy]

My bad, thought I read everything