1997 TP no fuel pressure

[LMP]

BLown ignition module (just the wafer, not the coils) can inhibit injectors and fuel pump, except initial prime , and still have spark. An ignition module is around 69$ new on ebay.

[old_master]

At the ECM connectors, check these also:

Battery voltage to ECM circuits:
C1 pin 20 red wire hot at all times
C1 pin 19 pink wire hot in START & RUN
C1 pin 68 pink wire hot in START & RUN
**The two pink wires are different circuits and are fed from different fuses**

ECM grounds, all must be less than 5 ohms to ground:
C1 pin 60 tan with white tracer
C1 pin 21 tan with white tracer
C2 pin 60 black with white tracer
C2 pin 21 black with white tracer

[old_master]

Originally Posted by LMP

BLown ignition module (just the wafer, not the coils) can inhibit injectors and fuel pump, except initial prime , and still have spark. An ignition module is around 69$ new on ebay.

Great idea however, there is no voltage signal from the ECM to the fuel pump relay, (which totally bypasses the ignition module).

[jackel440]

Originally Posted by old_master

At the ECM connectors, check these also:

Battery voltage to ECM circuits:
C1 pin 20 red wire hot at all times
C1 pin 19 pink wire hot in START & RUN
C1 pin 68 pink wire hot in START & RUN
**The two pink wires are different circuits and are fed from different fuses**

ECM grounds, all must be less than 5 ohms to ground:
C1 pin 60 tan with white tracer
C1 pin 21 tan with white tracer
C2 pin 60 black with white tracer
C2 pin 21 black with white tracer

Nieghbor didn't show up last night.So I hope he comes tonight.
I will go check these with my meter in a little bit as soon as the kids get home from school.

[jackel440]

Originally Posted by old_master

At the ECM connectors, check these also:

Battery voltage to ECM circuits:
C1 pin 20 red wire hot at all times
C1 pin 19 pink wire hot in START & RUN
C1 pin 68 pink wire hot in START & RUN
**The two pink wires are different circuits and are fed from different fuses**

ECM grounds, all must be less than 5 ohms to ground:
C1 pin 60 tan with white tracer
C1 pin 21 tan with white tracer
C2 pin 60 black with white tracer
C2 pin 21 black with white tracer

Everything checks out correct with what you have listed.
We did hook the scanner to the van,and it still has no comunication.

Is there a certain wire and pin out number at the computer I can check from the OBDII connector to the ECM harness for reisitance to see if there is an open wire?
Any reason why I still would not have any comunication from the ECM other than maybe it's dead?

[old_master]

I pawed through a bunch of schematics and can't find what wires go to the OBDII connector. Check out post #27 again.

[jackel440]

I think we have come to the point she is going to by a ECM for the van.I am at a loss to know where to go any further on it.

[old_master]

Let us know what happens.

[LMP]

Originally Posted by jackel440

I did check for the voltage during the pump prime nothing there.I checked several times..

Yes..the prime would run only on the first KEY ON..then the pump will wait for crank signal (fed through the ignition module) to turn on again. Pump relay is acted on by the ECM (as well as injectors) , and ECM waits for crank pulses. Turning key OFF then ON will NOT prime again, except if you wait for several minutes. THis is designed so you cannot flood the engine.

[old_master]

Originally Posted by LMP

Yes..the prime would run only on the first KEY ON..then the pump will wait for crank signal (fed through the ignition module) to turn on again. Pump relay is acted on by the ECM (as well as injectors) , and ECM waits for crank pulses. Turning key OFF then ON will NOT prime again, except if you wait for several minutes. THis is designed so you cannot flood the engine.

Each time the ignition is turned to the RUN position, the ECM activates the fuel pump relay for 1 to 2 seconds, (pump prime). The fuel pump pressurizes the system past the injectors and up to the fuel pressure regulator. The regulator bleeds any air that might be in the pressure line back to the tank, along with any excess fuel, and allows the system to acheive operating pressure. The injectors are not activated, (opened) during pump prime.

When the ignition is turned to the START position, the fuel pump relay is activated continuously provided the ECM receives a pulse signal from the crankshaft position sensor. After the engine is running, and the ignition is turned to the RUN position, the ECM will keep the fuel pump relay activated, as long as it receives a signal from the crankshaft position sensor. If the signal is interrupted, the engine will stall, and the ECM will deactivate the fuel pump relay 1 to 2 seconds after the crank signal is lost.

The ECM sends a pulsed ground signal to the injectors based on the signal from the crankshaft position sensor. The ignition module, (which fires the ignition coil), is also controlled by the ECM based on the same data from the crankshaft position sensor.

If the throttle is held wide open during cranking, the ECM will not activate the injectors. The is only means for unloading a flooded engine, there are no provisions to prevent flooding.

[LMP]

Originally Posted by jackel440

I have no manuals or schematics to trace what goes where on the van.Aaron

www.avigex.ca/xport/enginewiring1of3_19931.pdf
www.avigex.ca/xport/enginewiring2of3_19932.pdf
www.avigex.ca/xport/enginewiring3of3_19933.pdf
I hope the problem will be solved so we might possibly all learn something new and useful to next forum members coming with similar problems. . .

[jackel440]

OK the van is now running with the new ECM.
I have been working 16hrs the last week so I had not had time to work on the van.I got the ecm installed last night before passing out in bed.What a relief it was to turn on the key and hear that pump prime up.

I would like to thank old_master for his help in helping me track down the circuits.

After not getting any communications with the scanner and ECM,and knowing I did have a blown fuse on the comp. circuit.I had a reservation it was the computer,BUT I didn't want to just swap parts.After eliminating all the circuits it did come down to the ecm.
I did purchase it from ebay from a company that sells refurbished units with all the latest factory updates.Came packaged nicely and looked like a new one.
Thanks again for all the help and Ideas.I also will do my best to stick with mopars.As I have more resources to work on those.
Thanks again