need help with no spark

[lennon]

i was driving my 11/85 eta and the car stalled out as i took off from a light and wont start. ive had it towed to my friends house (was far from mine). it cranks fine but is not getting spark at the plugs.

ANY input on what might cause this to just happen out of the blue? does my car use the CPS for spark because ive heard early models dont? what else can i check? i dont have the bentley with me. any help is appreciated thank you!

[jmc1590]

Yes, the '85 eta still uses a CPS, but not the one mounted in front of the engine. It uses the sensor mounted in the bellhousing. (Adjacent to the speed reference sensor, also in the bellhousing.) The reference sensor should test out at ~960 +/- 96 ohms between pins 1 & 2, and 100K+ ohms between 1 & 3 and 2 & 3. Refer to the following picture for the pin locations.


If you find that your reference sensor fails the electrical test, you can swap the speed and reference sensors, as long as you switch both the wiring connections and the bellhousing positions.

Other ideas ... Main relay? (You can test for power at an injector with the key on.) Or possibly the reference pin has broken loose. I do know that I had a very similar experience that turned out to be a cracked solder joint within the ECU. (No ECU power = no spark.)

Good luck.

[lennon]

okay,

no spark still. ive got power to the coil. coil resistance checks good with the specs i have. speed and reference sensor both check out good and they are only 2 years old. the ecu plug has power to the power input pins. also switched out my chip for the stock one but no go. the fuel pump isnt coming on either of course.

how can i see the reference pin on the flywheel? take off the cover? someones bringing me another ECU to try. if that doesnt work, what else can i check?

this happened after driving normally for months, i let out the clutch at a light and it just stalled. happened 2 years ago and it was the reference sensor. but this one checks fine...

again any more help is greatly appreciated!

[lennon]

update-

dude came by and i tried his DME but no go still. i did not get to test my DME in his car, but hes pretty sure the one he gave me works. so if its not the DME, it must be the crank sensor? but mine has the right ohm reading, so what can i test?

edit- i was thinking i might be able to check continuity from the sensor to the DME plug. i have the plug pin diagram for my car, im not sure which ones to check and if this is even helpful. my idea is maybe the wiring is shorted or something somewhere along the way.

i have pin 8 bk wire engine speed sensor, pin 25 yl wire ref point sensor, pin 26 bk wire ref point sensor, pin 27 yl engine speed sensor. these are from the ETM, are they correct? which ones should i be checking?

[TheB1G Lebowski]

I too am thinking cam/crank sensor. I had a jeep in the shop the other day no spark no fuel. Wiring from PCM to sensor was good, and voltage/ohms good, but part was bad. Did you take the sensor off and check it? What type of sensor is it hall effect etc?

[jmc1590]

Don't worry about checking the speed sensor. A failed one will not affect operation (too much.) The reference sensor does connect to the ECU via pins 25 & 26.

To verify the reference pin, other than pulling the transmission, remove the reference sensor, shine a light up there, and slowly turn the engine over. There are other threads on the subject that should be able to provide you with pictures of what to expect.

All of this applies if this is an eta with Motronic 1.0 (007 or 027 ECU.) If the electronics are different, then disregard.

[lennon]

it was dark when i got home and couldnt check if the pins still on the flywheel, hopefully tomorrow i will be able to. i will try swapping the two sensors (locations and wires). i havent tried that yet because they both read the same ohms (good). my tach doesnt move when im cranking though. isnt that what the other sensor is for? i doubt BOTH of these sensors would go bad at the same time, plus they are only a couple of years old. to me this could mean the dme is bad (also since there is no fuel), but ive tried another and it didnt change anything. maybe something is shorted out in the harness? the main relay is the only one for the dme, right? ive heard something about one in the trunk. the dme is getting power through pins 18 and 35 though so i dont think its a relay.

any other ideas guys? jmc1590 thanks a lot as youre the only one with any input at all! and yes, i have searched like crazy here and elsewhere.

[jmc1590]

Yes, the main relay is the only one that the ECU depends upon. (Fed via pins 18 and 35.) However, only one leg of the relay goes to the ECU. The other feeds the fuel pump relay and your injectors. Try this quick test. Measure voltage from an injector to ground with the key in ON. If the main relay is functioning correctly, you should get battery voltage.

No tach while cranking does sound like a ECU problem, but your swap should have ruled that out. Ensure that the correct sensor is still connected to the correct connector. Reference sensor: Grey connector - "B" on bellhousing. Speed sensor: Black connector - "D" on bellhousing. (If they were mistakenly swaped, they would test correctly, but not run. For that matter, try swapping them. It won't hurt to try. Just verify which goes where.) As far as does the speed sensor feed the tach, no it does not. The tach gets it's signal from Pin 1 on the ECU (which also happens to control the coil.) It does feed the idle control module and from my understanding determines which batch of injectors to fire. Make sure that the black wire on pin 1 of the coil is still making good contact. (No ground from the ECU, no tach & no spark.)

As far as other "no spark" ideas, the coil primary side (15, green wire) should be +12 V hot with the key in run or start.

[lennon]

i didnt really mean does it feed the tach directly, just that the tach needs the speed sensor to show any rpms. but either way, no tach, no spark, no fuel. maybe the other ecu i tried was bad too? doesnt seem likely though. i need to test my ecu in a running car. the wires on the coil are good and it gets 12v, and the coil resistance matches what the bentley says. i will certainly test for voltage at the injectors just to see whats up. still got power to the ecu though, so i think itll be there too. also need to check for the reference pin still. hope thats not broken off or ive really got some work to do.

[nando]

the reference pin on your flywheel is probably broken off. very common problem.

[lennon]

well the pin is on the flywheel. it looks a bit ugly though, can anyone direct me to a picture of what it should look like? ive searched, i guess ill keep searching if no one can show me a pic. i also swapped the two sensors and plugs and no change. i cleaned the ground on the oil pan and the one on the intake manifold. damn this is annoying!

edit- found a nice pic of what the pin looks like. mines definitely not perfectly rectangular like that. mine looks like it has some wear to it and like the face of it isnt flat. it is there though... i wonder if this would cause my problem.

[homegrone30]

This sounds oddly like what happend to my eta look under the drivers side dash and there is going to be another big relay that is actually connected to the computer from the top. Take this relay out pull the plastic casing off and see if you can find a burnt connection inside.

[lennon]

update-

no power to fuel pump under backseat, even when i jump the relay. still got power to ecu and no spark. im about to go check for power at the other pump and check all the fuses (for the 10th time) and the relay homegrone30 is talking about. anyone have any more ideas as to why i wouldnt even get power to my fuel pump?

edit- also, to add complication to my problems, my cold start injector opens. i pulled it out and cranked the engine and it opened a couple times and squirted out a small amount of gas with little-to-no pressure (pumps not running). this means my ecu is telling the injector to open, so it must be getting the timing signal from the flywheel, or am i wrong? now i just need to figure out why the pumps not getting power and why i still have no spark!

[lennon]

update-

well it seems like the cold start injector opening was a fluke. it was only for a second anyway and there was no fuel pressure.

neither pump has power going to it with the key on, or if i jump the relay. when i put power to the in-tank, nothing. so i guess its bad? possible been bad for a while.

i put power to the second pump and it pumps fine, but the cold-start injector doesnt fire now.

i thought jumping the relay should turn the pump on regardless of other issues with the ECU, etc. anything that would keep the direct jump from running the pump, when 12v to the pump terminals runs it fine?

i tried to check the relay under the dash, but it does not open or anything so i cant see any of the connections. anyone know if i can ohm out the pins/which ones? ill check the etm i guess. also cant check the 'fusable link' in the trunk, because my trunks been stuck closed for months. i can see how to open it but cant reach far enough through the ski-hole. sucks hard!

im thinking it may be my damaged reference pin on the flywheel, because the injector isnt firing and im not getting spark. as to why my fuel pumps not coming on (even when relay jumped)... maybe whatever caused that happened at the same time somehow? thats what is confusing me the most, i dont see how the two could be related.

edit: and yes theres power to the fuel pump relay.

[homegrone30]

I tried to check the relay under the dash, but it does not open or anything so i cant see any of the connections.

Dude use your imagination you can get in those Ive opened two different styles. If its all rubber around the connections take a razor blade and cut along the outside edge. Then a small screwdriver and some prying should get it out. The other style you should be able to open with a pair of needle nose and a screwdriver.