86' 740 Fuel Delivery Problem

[waynegarbo]

Download and save this: TP31058_1

See page 20 (PDF's page 20), and look for terminal #17 on LH control unit (217).

From terminal 17, there is a colored wire that goes to the relay, so find it at the relay. Remove relay, and hook one side of your volt-meter to a positive voltage, and the other side to terminal's #17 clip at relay. Crank engine...is there voltage? If not reverse voltmeter leads...???

Download the enclosed document, and notice terminal #9, check it too. It appears to be a positive voltage.

I think on LH 2.0 thru 2.2, the engine must be cranking before relay circuit is energized.

Not related: Repairing Your Own LH 2.2 ECU

Terminal #17 feeds to terminal 86/2 at the relay. I have good continuity, I will check for voltage again, I'm sure from all the work I've done, I believe there was voltage there.

[waynegarbo]

Download and save this: TP31058_1

See page 20 (PDF's page 20), and look for terminal #17 on LH control unit (217).

From terminal 17, there is a colored wire that goes to the relay, so find it at the relay. Remove relay, and hook one side of your volt-meter to a positive voltage, and the other side to terminal's #17 clip at relay. Crank engine...is there voltage? If not reverse voltmeter leads...???

Download the enclosed document, and notice terminal #9, check it too. It appears to be a positive voltage.

I think on LH 2.0 thru 2.2, the engine must be cranking before relay circuit is energized.

Not related: Repairing Your Own LH 2.2 ECU

Terminal #17 feeds to terminal 86/2 at the relay. I have good continuity, I will check for voltage again, I'm sure from all the work I've done, I believe there was voltage there.

The other thing I forgot to mention was I have the proper power signal and voltage from the ecu to the icu. Also, today at work I asked a certified mechanic, if I have voltage at my fuel pump can I still have a bad ecu and he said yes, you have a failed ground in it cause I mentioned to him my ignition start does not produce fuel pressure but my relay junction jump to the fuel pumps does. This is why I believe my ground in my ecu is out because all three of my fp relays check out and look good and all continuity in my relay junction checks out and the continuity for pin#17 to 86/2 and #21 to 86/1(which is my ecu ground, right?)are good.

[waynegarbo]

The other thing want to mention is fuse #11....for the fuel tank pump. There is not power on it with a test light. So I believe from looking at the the schematic for B230F LH 2.2 for the ECU and the FP Relay, it seems to me that 87/2 junction terminal has to close for current to flow through but with a working ground from the ecu....and I think this is my problem.

[93Regina]

have voltage at my main fuel pump, jumped the relay junction box at terminal 30 to 87/2

Jump it...will vehicle run?

[93Regina]

Mine does not have the RPM..

Computer uses distributor signal...which is a RPM signal.

[waynegarbo]

have voltage at my main fuel pump, jumped the relay junction box at terminal 30 to 87/2

Jump it...will vehicle run?

If you mean 87/1, with 87/2, and 30 and start, No.

[waynegarbo]

Mine does not have the RPM..

Computer uses distributor signal...which is a RPM signal.

Yes, correct, but I don't have the RPM(crank)sensor....

[waynegarbo]

What would happen if I took the 40 amp, relay junction 30(hot all the time)and jumped it to fuse 11, which is 15 amp...?????

[waynegarbo]

Mine does not have the RPM..

Computer uses distributor signal...which is a RPM signal.

Also, FYI, I put a used distributor in this car about 3 or 4 months ago....again, it has spark, is not leaking, hall sensor wires at the connector and connector are clean...but it is an old distributor...I do have a signal from the sensor that makes the tac needle moved slightly on crank...but I never
did the hall sensor test with a volt meter at icu pin, I believe #24, with the key on, and someone manually spinning the crank, and observing the
volts ea time the vane and hall opening pass the sensor...I am concerned and wondering if indeed this IS THE SIGNAL THAT WORKS WITH THE
ECU?

[waynegarbo]

Download and save this: TP31058_1

See page 20 (PDF's page 20), and look for terminal #17 on LH control unit (217).

From terminal 17, there is a colored wire that goes to the relay, so find it at the relay. Remove relay, and hook one side of your volt-meter to a positive voltage, and the other side to terminal's #17 clip at relay. Crank engine...is there voltage? If not reverse voltmeter leads...???

Download the enclosed document, and notice terminal #9, check it too. It appears to be a positive voltage.

I think on LH 2.0 thru 2.2, the engine must be cranking before relay circuit is energized.

Not related: Repairing Your Own LH 2.2 ECU

Terminal #17 feeds to terminal 86/2 at the relay. I have good continuity, I will check for voltage again, I'm sure from all the work I've done, I believe there was voltage there.

ok, volt meter on 86/2 and ground(that goes to Pin #17)but with a weak battery, gave me a slight jump of .08 volts...will have to try again later...if I recalled I had alot more about two weeks ago...