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CPS Differences - Another No Spark

ScotchWhiskey

Member
Joined
Sep 6, 2013
So the back story....Made the mistake of running some Seafoam though my FPR vacuum line on 1992 240 sedan with B230f AW70. The car smoked up and eventually died. Restarted it and it ran some more, throttled it at the engine by hand and it inevitably died again.

Couldn?t get a restart, so I assumed the plugs were wet/fouled. Pulled plugs and cleaned them, cranked engine to dry cylinders out. Reinstalled plugs and still no start, so I pulled #1 wire and grounded a spare plug and had no spark. New car to me so figured it needed a stage zero so I installed plugs, wires, cap, and rotor that I had on hand. Still no spark, but I wasn?t expecting one at this point.

Haven?t tested coil voltage or fuel pump relay yet, but I can hear a fuel pump prime. So instead cleaned and greased the heat sink on the ignition control module. I also looked at the crank position sensor and noticed the shielding ground wire was exposed and insulation was crumbling. Decided to pull it out and replace with a spare, but the sensor I am replacing has a round/oval 3-pin connector instead of the square/rectangular 3-pin that I have seen in every other car? Any idea if there are multiple parts for this application? I believe the car is LH2.4 based on the 5th and 6th VIN and the 016 MAF.

Thanks in advance.
 
Incandescent? Or LED?

Incandescent to coil negative to ground. Ign on. Lamp should be on. Crank. Blink?

LED lamp to power stage signal wire from EZK. Crank. Blink?
 
Will test and report back. CPS is removed though so I presume this will affect diagnostics. I can replace it and see. Any word on the differences in connector types?
Thanks for the quick response.
 
Test for fuel injector pulse too. Test lamp backprobed between the two wires. Blink?


Yes, you need a crank sensor installed. Inspect the connector for recessed, or corroded terminals. Drag test the female terminals for correct tension with a spare male terminal.
 
I would like to replace crank sensor with a new Bougicord unit while it’s already out, but I can’t find anything for sale that matches my connector. I have a 3-pin oval connector with circular pins. Wonder what’s up with that and if I will need to splice a square-end connector into my wiring harness in order to accept a new sensor.
 
Good idea on using the bougicord brand, not a part you want to go cheap on. I?ve never seen a different plug either.
 
Incandescent? Or LED?

Incandescent to coil negative to ground. Ign on. Lamp should be on. Crank. Blink?

LED lamp to power stage signal wire from EZK. Crank. Blink?

No blinking on crank with LED light to power stage signal wire (white/red). Also no blink on crank with incandescent bulb on coil ground (blue). Ignition switch seems to be very touchy and can turn test lamp on and off in key position 2 with very minimal effort.

A buddy also diagnosed the crank sensor issue as a generic/parts store 3-pin oval connector re-pinned from the factory harness along with a potentially unknown sensor. Looked as if the metallic point on the sensor had been grounded down a bit, also the crank sensor bracket was deemed loose upon reinstallation. Ground down a 10mm box wrench and got it tight, but someone has definitely been chasing issues here in the past.
 
Step 1, unfubar the car
Step 2, install correct part
Step 3, see if previously fubar'd issues, now corrected, have solved the problem.

Digging into something that's been hacked in the past is usually such a PITA.
 
Step 1, unfubar the car
Step 2, install correct part
Step 3, see if previously fubar'd issues, now corrected, have solved the problem.

Digging into something that's been hacked in the past is usually such a PITA.

I spliced a used known good crank sensor into the existing connector that matched what was on the car to see if it would remedy the situation, but it was a no go. Guess next move is to pull a CPS connector off a spare harness and attempt to re-pin it in place of the aftermarket connector and then install a brand new crank position sensor. I?m about stumped on this thing.
 
Do you have injector pulse?




Click my signature.

Sorry, not seeing anything in the signature. I?ve read through your No Start thread dozens of times though. I know you mentioned test light backprobed between the two wires and looking for a blink. I?m assuming this is looking for battery power/voltage between the two injector wires when cranking?

I?m pretty sure I have no crank signal. I?ll need to pull the haphazard test sensor I put together and re-pin an OEM connector and start with a new quality sensor. I?m also uncertain if the flex plate is damaged since it looks as if there was contact with the ?point? on the sensor that was originally removed. No wonder the LS swaps have gained so much ground... :rofl:
 
Ok, first question, following what was mentioned by Simon a while back in post 13. What engine management is on this? Is it Regina, 2.4, or 3.1? I don't BELIEVE Regina hit the 240's, which would leave it at 2.4 or 3.1. If the harness also has the oval connector, is there a chance you've got a funky engine harness on it as well? Granted it was running, but if it's some funky harness, that changes the diagnostic game greatly. It does sound like a crank trigger issue most likely, but more info would help at this point.
 
To test the crank signal. You test the INPUT wire to the ignition amp. Not the red/white output wire. I think it may be pin 5 that is the trigger input signal from the ezk computer. If there is no signal in the INPUT and you know the wiring is good. Then you have a bad engine speed sensor or bad ezk computer. A good quality meter is better to use. Then you can see the voltage varying as the signal is triggered.
 
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