Will Not Stay Running??

#21

[quote=“ilateapex” post=64833]Thanks Robert.

The problem has persisted through 2 different kill switches. CPS has been replaced and checked. I just did the timing belt and the problem happened before and after the change and the damper was installed tight and does not wobble. I will try the injector harness.

What do I do to get the batt warning light to work again?[/quote]
Power to the light is furnished by one of the switched fuses for the cluster (I don’t remember which). Exciter power flows through the bulb, then to C101, through the engine harness, to the alternator. The exciter circuit in the alternator is ground for the bulb and when the alternator produces output the back EMF on the exciter causes the bulb to go out.

The first check would be to see if the cluster fuses are good. Then check for power at C101 pin 1 and follow that with a check for power at the exciter lug of the alternator. If there is power at both of those points, the alternator could be bad. Grounding either point should light the bulb.

#22

Trying to make some progress but not really.

I replaced the altenator and now have working batt light on the dash and I get 13.6 volts sooner then before. But still have the issue.

I replaced the injector harness and no change. I changed the cap and rotor with no change. Swapped main relay with no change. At least it does not seem like any change.

Here is some more detail of what it does now. Warm engine (or cold for that mater) Start car. Idle’s fine. RPM will start to dip and the ECU or whatever compensates and keeps it running. Will do this a few times and then die. Start car. Hold RPM to say 2000. Will stay like that for a time and then RPM will dip a little and Check Engine Ligth will flash. It will do this a few times and then die.

I have checked the voltage at the ECU and it seems steady until it dies. It sometimes dips with the engine but it seems like it is more reacting to the engine then the other way around.

#23

The voltage at the DME varying with dips in idle speed is to be expected. But even when the engine dies power should be present at DME pins 27 (START input), 18 (un-switched power, hot all the time), and 37 (switched power from the main relay) as long as the ignition is on. The START input comes from the ignition switch, through C101, and then through the harness to the DME. That signal tells the DME to turn on the main relay and power up. Which of those goes away when the engine dies?

#24

None that I can tell loose power. I checked all three and as soon as the car dies it goes to battery voltage.

I am thinking vacuum leak right now and trying to make sure it is all buttoned up.

#25

GOT IT!!!

Yoda Levie put me on the right track. I double checked the voltage at the ECU and for some reason pin 27 did not sound familar. When it was checked I found that it only had 12.7 V where the other power sources had 13.6 V. Looking at the ETM, this is the green wire that comes from the ignition switch, through the OBC relay and then to the coil and ECU. I found that the plug into the OBC relay was loose and when removed one of the pins was black. I cut the wires from the relay and shorted them and then pluged it back into the C104 plug similar to the way it would be in a non OBC car basically bypassing the OBC relay. Now she purrs like before and is rock solid. Basically the coil was seeing less then optimal voltage and the combination of that and the low voltage to the ECU was causing the issue.

Thanks so much for all the help.

#26

Hoorah! I love stuff like this that helps so many others and allows you to constantly learn to trace where problems originate. Glad its fixed, it was quite the soap opera!

#27

congrats Michel

#28

Awesome. Levie strikes again.