Completely confused as to why my engine isn't running right

[kingmanjr00]

I forgot to mention that I have tested the sensors back to their respective pins at the ECU for continuity to make sure there are no breaks in the wire harness, and everything tested OK. I purchased the refurbished ECU from ModuleExpress out of Florida. Everything that I am seeing is pointing back to the ECU not working, as the coil has power, just isn't getting a signal. Has anyone had experience with ModuleExpress, or have other suggestions that I can look at?

[DrTwincam]

It's been outlined. I would verify the Hall Sensors are producing a pulse. Test first at the connection from the sensors then each connection going up into the ecu making sure you have a consistent pulse all the way through the harness. Only then can you point to the ecu and only if everything else is testing out fine as articulated earlier. It's tedious but required if you want to really start ruling things out, If you have no pulse from the sensors while installed and cranking, you can pull them and test with anything metallic like a screwdriver, swiping it back and forth to see if you then get a pulse. It must be very close to the sensor tip. I've heard only one time of the trigger falling out and that was from abuse. The main grounds in the cabin area will usually but not always yield some gauge flutter or other symptoms if loose. Euro 745's were notorious for wiping out the fuse in the ECU from loose grounds behind the dash. Follow the outline that was given earlier and be certain with each step. You'll find it.

[kingmanjr00]

I was able to check the speed and reference sensors and they both were creating a pulse at the connection with the harness as well as their respective pins at the ECU. Now that I know they are sending a signal, does that point to the ECU? Also, has anyone used ModuleExpress?

Thanks again for the inputs.

[DrTwincam]

As long as everything else mentioned checks out, then yes, time for an ecu. You have certainly put your time into this one.

[DrTwincam]

You know, something struck me as odd. When I looked at the pictures in the provided motronic troubleshooting guide, I noticed the Grey Connector (Reference Sensor) was located nearest the intake runners. Doing some fiddling w my car today, I noticed the Black Connector was nearest the intake runner side. I then pulled up a number of engine bay pics and noted most (not all) are like mine w black connection nearest the intake side. With that in mind, Try switching the two connections around and see what you get. To be certain, as I understand it, the Grey connection needs to be connected to the sensor lowest on the bell housing just below the speed sensor.

[kingmanjr00]

I did check to make sure the speed and ref sensors were in the correct location. I just got my ECU back from Module Experts. They said that the one I sent in (the one they replaced my original one with) tested bad and they needed to send out to their warehouse for a replacement. Took over 2 weeks to get the new one back to me. When I received it, I put it in, and there was no change in symptoms. Still no spark, still no signal from the ECU to the coil.

Does anyone have any experience with this company? Are they just taking my money and sending me junk? Any other suggestions on what I could check out from here?

[bpoliakoff]

There is a guy who really knows his ECU stuff. He calls himself Fuel Injection Corp . I am going from memory. I spoke with the guy many many years ago and I believe he is an electrical engineer that totally knows what he is doing. I was going to send him my ECU and he told me the one I have never goes bad and don't waste my money but if I really wanted to, he'd check it for $75. He is in Tracey CA where the US Radiation lab is and I have to think anyone around there has to have a strong engineering background. At the time he was quite willing to spend time on the phone with me. You might google him up and give him a shout or if not see if someone here has an extra known good ECU they will lend you

[DrTwincam]

I too forget the name of the guy in Tracey. He was, may still be, the best around. I know we used to send him all kinds of different Bosch stuff to test and repair. That was in the late 1980's...