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I been helping a friend battle through this 89 ranger with a 2.3L 8 plug engine that had its body removed and a Studebaker truck body installed onto it. Very long story short, we took over this project truck and the people who started this conversion really didn't know what they were doing and my buddy has had to fix a massive amount of wiring issues. We think we are down to the last drive-ability issue but its a wild one.
Here is the problem. If the truck is started cold with SPOUT connected, within about 1.5 min it will stall. The engine actually progressively idles worse and worse then stalls. Once hot it won't stay running at all unless you throttle it and it will start pinging/knocking and misfiring. It was discovered that if both the headlights were on and the aftermarket electric cooling fan is running, it will drive just fine with maybe a very slight rough idle. Both the headlights and the cooling fan must be running. Turn either one off and the crazy returns.
I had both the ign coils replaced and new plug and wires (both sides of the head). Both coils had heavy spider checking around the posts in the resin and both coil packs had at least one hole heavily corroded inside it. Supposedly this truck has a new timing belt, new crank sensor, new ICM/DIS module, the dual 6 pin connectors going into the module have been replaced. Power steering switch was replaced and wiring repaired to fix a code in the ecm.
Troubleshooting this truck with a breakout box lead to the discovery that if the spout is disconnected either by removing the jumper or using the selector switch on the bob allows this truck to idle just fine and drive fine with or without the cooling fan running and headlights being on. We have been pretty much stuck here for a couple of months as the truck more or less drives fine with no spout. Me not having any experience with non OBD-2 vehicles lead me to start doing a lot of research and discovered Danner fighting with a 4.9 f150 TFI module video where the ecm via spout was sending a junk signal to the module and causing a no-spark. Because of that I went out and got a Vantage Ultra to look at wave forms from the CMP(CID), Pin 5 on the ICM with no spout connected, what the spout signal looks like from the ECM at the spout connector (jumper removed), with SPOUT connected at pin 5 on the icm with and without the headlights and fan running.
This is where I'm completely lost. I don't have any experience with a scope so I'm not sure if I have it configured right but these wave forms are wild to me. Does anyone know where I can find known good waveforms for these signals? My pictures and video recording are too large for the forum.
I didn’t look at the file however, my thought would be to think about what the cooling fan and headlights being on is doing. It’s proving either a power or ground (probably power). I’d be willing to bet that they may have spliced a wire into either the headlights or auxiliary cooling fan that is probably providing power to a sensor.
Making Pressure Differential Sensors (PDA Sensors) for pressure pulse diagnostics.
Currently servicing Central Texas.
It runs flawless without the spout connected. It doesn't change any drive-ability when the lights and fan are on or off with it disconnected. My biggest concern why now is why I have a square wave that goes to about 9 volts riding on pin 5 of the dis when the spout is disconnected. With the spout disconnected looking at the pcm side of the square wave doesn't look abnormal other than it runs up to 14v at peak.
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