1989 No Spark No Start PLEASE Help

Alright I'm gonna need help from the Bosch ignition experts on this one. I'm at my absolute wit's end with this ****ing car and I'm seriously considering taking it to the junkyard. Please help me avoid having to do that.

Currently trying to chase down a no spark/no start issue on my 1989 (so it has Bosch LH2.4) 245. It was intermittent for a couple weeks but now it won't start at all.

The whole system looked pretty old so I replaced (in order):
-Crank position sensor (the one on top of the bellhousing)
-Cap/wires/plugs/rotor
-Coil
-Power stage (aka the ICM aka the ignition amplifier, it's the little thing behind the driver's side headlight)

None of that made any difference. Still no spark and no start. I removed the EZK box, took the computer out just to see if there was any obvious corrosion or blown components. The thing still looked brand new so I put it back in it's case.

Earlier today I put my meter on pin #5 of the plug that goes to the ICM up by the driver's headlight. This is the pin that should be receiving the AC signal from the EZK (which is receiving it from the crank position sensor) and got nothing. So I know it's either an issue with the brand new CPS, the EZK, or the wiring somewhere between the three components.

I tested the resistance of the CPS and got 170 ohms which is right within spec (150-230 ohms). Next I'd like to try and test to see if the sensor is putting out a signal while the engine is cranking, but I'm not sure how to do that. There are three pins on the connector and I don't know which ones I should be putting my probes on while the engine is cranking.

Can anyone offer any advice or explain to me how I can test the CPS? Any help is greatly appreciated.

Also I wanted to add that all parts were OEM or equivalent and I also replaced the fuel pump relay as that was originally what I suspected was causing the intermittent no-start.

Got a test lamp?

Does the diag box do any blinkys?

A weak point is the fuse holder at the battery. The holder melts/corrodes= entire EFI is DEAD

ZVOLV said:

Got a test lamp?

Does the diag box do any blinkys?

A weak point is the fuse holder at the battery. The holder melts/corrodes= entire EFI is DEAD

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Yeah I have both an LED test lamp and a digital meter which is what I've been using to test this stuff.

25A battery fuse is one of the first things I checked even though the whole holder + fuse was replaced within the last year. Looked totally fine.

No codes. 1-1-1. I also ran the procedure for the on-board diagnostics to test the crank position sensor and it said that it was good, although I'm not 100% convinced based off of that alone.

Test lamp between coil negative and ground. Key on, lamp on. Crank, lamp should blink.

Lamp between the two fuel injector wires. Got pulse?

Click my sig.

The problem could very easily be the ignition switch. There are several pins that supply power depending on switch position. I've replaced several ignition switches in the last 10 years that cranked the engine fine, yet, didn't supply power to the other components needed to make the car run.

ZVOLV said:

Test lamp between coil negative and ground. Key on, lamp on. Crank, lamp should blink.

Lamp between the two fuel injector wires. Got pulse?

Click my sig.

Click to expand...

I did that already and got nothing, which is why I then tested between pin #5 on the powerstage connector and ground. And also got nothing there. I haven't checked a fuel injector yet but plan to do that tomorrow.

2manyturbos said:

The problem could very easily be the ignition switch. There are several pins that supply power depending on switch position. I've replaced several ignition switches in the last 10 years that cranked the engine fine, yet, didn't supply power to the other components needed to make the car run.

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That is true but the on-board diagnostics are working fine so I'm fairly certain the ECU and EZK are getting power with the switch on KPII

TriaxialBulls said:

That is true but the on-board diagnostics are working fine so I'm fairly certain the ECU and EZK are getting power with the switch on KPII

Click to expand...

Not necessarily. When you engage the starter a different set of pins in the switch are used. Have you checked for power at the coil? You might try putting the switch in the run position and trigger the starter with a remote starter button.

2manyturbos said:

Not necessarily. When you engage the starter a different set of pins in the switch are used. Have you checked for power at the coil? You might try putting the switch in the run position and trigger the starter with a remote starter button.

Click to expand...

Yep I'm getting 12V to both sides of the coil with the key on. The diagnostic procedure for the crank position sensor involves cranking the engine and everything checks out good when I do that so again I'm fairly certain everything that needs key power is getting key power

Are the terminals nice and tight on all of the components you replaced? I've bent a few when changing out a part and had to replace. On the fuel pump relay, the connectors will sometimes crack on the sides of the terminal. Remove them from the connector with a small flat pick if you think that looks suspicious. Check the bottom side of the wiring in the black tubing as sometimes it becomes chafed.

Check that stupid fuse by the battery. It’s the fuse for the ecu and if it’s blown the car won’t start.

You can check that the ignition switch/neutral safety switch is bad by putting the key in position two, run a wire from the starter solenoid to the positive battery terminal. If it starts your problem is there.

Are you sure it’s ignition related? You’ve sprayed starter fluid into the intake and tried to start it and it still doesn’t start?

Marvelous3 said:

Check that stupid fuse by the battery. It?s the fuse for the ecu and if it?s blown the car won?t start.

You can check that the ignition switch/neutral safety switch is bad by putting the key in position two, run a wire from the starter solenoid to the positive battery terminal. If it starts your problem is there.

Are you sure it?s ignition related? You?ve sprayed starter fluid into the intake and tried to start it and it still doesn?t start?

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I took a plug out, grounded the threads on the negative battery terminal, cranked the engine, and observed for spark. Got nothing.

Then I took the lead off of the coil, held it about 1/4" from the negative battery terminal, and got nothing.

So yeah, I'm pretty sure it's an ignition issue.

And again, as far as I can test I'm not getting any signal at pin #5 of the powerstage connector while cranking. So it's not even getting the proper signal that tells it when to fire the coil.

TriaxialBulls said:

... Can anyone offer any advice or explain to me how I can test the CPS? Any help is greatly appreciated.

Click to expand...

Testing by observing the AC output isn't going to be convincing using a DMM. The level is low and meters vary considerably in sampling rate and noise immunity measuring AC under a volt.



Best test without a scope assumes the flywheel or flexplate's tone ring is intact, so if you see the resistance of the CPS's winding all the way back to the EZK's pins 10 and 23, you can feel good about the CPS. Too many of these "I just replaced the CPS" stories end when terminal pushback is discovered in the harness connector for the CPS at the firewall.



Next place to look, use your LED test light, not your DMM to check the EZK's output to the ignition amplifier. It will blink on with each ignition pulse.







Next, check the coil terminal 1; the LED will be on and wink off with each ignition pulse. Usually this is where I start, since the two-wire connector in the coil harness is often a victim of corrosion, as are many connections in the battery's vicinity. Disable fuel by pulling the injector connectors and use the starter test terminal to crank.

cleanflametrap said:

Testing by observing the AC output isn't going to be convincing using a DMM. The level is low and meters vary considerably in sampling rate and noise immunity measuring AC under a volt.

Best test without a scope assumes the flywheel or flexplate's tone ring is intact, so if you see the resistance of the CPS's winding all the way back to the EZK's pins 10 and 23, you can feel good about the CPS. Too many of these "I just replaced the CPS" stories end when terminal pushback is discovered in the harness connector for the CPS at the firewall.

Next place to look, use your LED test light, not your DMM to check the EZK's output to the ignition amplifier. It will blink on with each ignition pulse.

Next, check the coil terminal 1; the LED will be on and wink off with each ignition pulse. Usually this is where I start, since the two-wire connector in the coil harness is often a victim of corrosion, as are many connections in the battery's vicinity. Disable fuel by pulling the injector connectors and use the starter test terminal to crank.

Click to expand...

Thanks for your help. This is the type of info I was looking for.

I used my test light and I'm not getting any pulse at the coil or at the #5 grey wire of the powerstage connector.

I got 170 ohms between pins 10 and 23 on the EZK connector so I'm fairly certain my brand new Bougicord CPS is good. The on-board EZK diagnostics still give me code 1-4-1 for it as well.

I tested all of the terminals on the powerstage connector for continuity with wherever they're supposed to go, and all tested good (except for that one black 'shiedling' wire which doesn't really 'go' anywhere).

I actually replaced the EZK today with a known good unit that just came out of a running car and did all the diagnostics above AGAIN and no change.

At this point I'm really at a loss. I seriously just want this thing to run so I can sell it and get it out of my sight. The car is going to the junkyard in the next week if I can't get it running.

Wait, should the shielding wire (pin #3 on the powerstage connector) be grounded? It looks like on the wiring diagram it's not actually connected to anything so I just wanted to make sure.

I also heard that if the TPS is bad, it could put the computers in 'flood' mode which will give you no spark or something like that. It seems to test good using the on-board diagnostics, but is this something I should look at?

TriaxialBulls said:

Wait, should the shielding wire (pin #3 on the powerstage connector) be grounded? It looks like on the wiring diagram it's not actually connected to anything so I just wanted to make sure.

I also heard that if the TPS is bad, it could put the computers in 'flood' mode which will give you no spark or something like that. It seems to test good using the on-board diagnostics, but is this something I should look at?

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What is heard is rubbish. The throttle position switch turns on the IAC when the throttle is closed. At full throttle while cranking it supposedly shuts off the injectors to clear a flooded engine.

2manyturbos said:

What is heard is rubbish. The throttle position switch turns on the IAC when the throttle is closed. At full throttle while cranking it supposedly shuts off the injectors to clear a flooded engine.

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Yeah it sounded pretty far-fetched to me.

But at this point, I have to suspect that it's some sort of other input into the EZK that is causing it not to send the pulse out to the power stage. I know that the CPS signal is getting to the EZK and that the wiring is good, but that signal just isn't getting to the powerstage.

I've spent absolutely ages looking at this wiring diagram: https://www.davebarton.com/pdf/Harness_LH-2.4-240EZKPinFunctions2021.pdf
are there any other sensors I should be looking at replacing? The temp sensor maybe?

I'm seriously willing to try anything at this point.

ZVOLV said:

Lamp between the two fuel injector wires. Got pulse?

Click to expand...

Yes? No?

ZVOLV said:

Yes? No?

Click to expand...

Can I measure this with the DMM? If not I'll go try to find some wire to shove in the socket so I can grab it with the clamp on the test light.