1990 740 gle gas delivery problem?

[joedrt77]

Did the rsr relay switch and jumpered the connector without the relay in, coil checks out .9 and 7.8 ohms, I have 12 volts on the + side of coil, still not getting 12 volts on the fuel injector connectors, trying to figure out how to test power stage module, can I assume that the power stage module is good because I have 12 volts at the coil or is that wrong?, thanks for response Regina 93.

[93Regina]

can I assume...rsr relay switch and jumpered the connector...fuel injector connectors

No, no, and no...

See figure 4, page 6 here.

If Radio-Interference Suppression Relay is jumpered correctly, what would one expect at fuel injector plug? Also, what is function of fuel system relay, in regards to Blue/Yellow wire?

[joedrt77]

I tested the f i connector with key on, no 12 v., jumpered rsr relay, still no 12 v., if I read diagram correctly blu-yell. wire from fp relay goes from 1 on relay back to 6 on relay, then pink n white goes out to canister solenoid and one goes to iac, I might have read it wrong, thanks.

[lummert]

The fuel pump relay triggers the radio suppression relay. The RSR supplies positive current to the injectors. The LH computer switches the ground to the injectors. If the FPR isn't functioning the RSR won't function. Bypass the fuel pump relay with a jumper wire running between 30 and 87a/87b. This will trigger the pumps and the RSR.

[joedrt77]

Wonder if this is a valid test? I jumpered the rsr relay then tested for 12 volt again at fuel inj. connector still no steady 12 volts, on one side I get like 3.5 volts then goes to 0 quickly, then when i take off the test lead and touch it back to same point on f inj. connector it reads 0 not 3.5 just 0, other side is 0, but as i understand one side will be 0, wonder if that works to rule out the rsr?, wonder if there's a good tutorial on testing voltages grounds etc. for the f i control unit and the ecu and or a good testing procedure for a car that won't start, there's a lot that want you to start the car to test but can't right now, thanks.

[joedrt77]

The fuel pump relay triggers the radio suppression relay. The RSR supplies positive current to the injectors. The LH computer switches the ground to the injectors. If the FPR isn't functioning the RSR won't function. Bypass the fuel pump relay with a jumper wire running between 30 and 87a/87b. This will trigger the pumps and the RSR.

Wonder if it's a break, near break or short in the wire running from the rsr to the f i injector connector?

[joedrt77]

The fuel pump relay triggers the radio suppression relay. The RSR supplies positive current to the injectors. The LH computer switches the ground to the injectors. If the FPR isn't functioning the RSR won't function. Bypass the fuel pump relay with a jumper wire running between 30 and 87a/87b. This will trigger the pumps and the RSR.

Did a jumper in fpr didn't start, when i pulled the jumper out less than 10 seconds is all it was in for and the jumper wire was really hot, got a burn from it, wonder if it should get that hot?

[lummert]

I forgot to mention that I used heavy gauge wire and a 30 amp fuse for the jumper. try connecting the jumper from 30 to 87a which goes to the pumps. Then try 30 to 87b which goes to the rsr. Does the wire overheat in both tests.

[joedrt77]

Ok, will try it, is there a good test for the power stage?, would like to test every pin on the stage and the stage connector, tested 1 and 4 on connector got 12 v, don't know how to test the rest, thanks.

[joedrt77]

the 8 dollar relays seem to have the same specs as the 65 dollar rsr relays, just different connector terminals, why not get one of those and a new connector, since my connectors aren't in that great of shape anyhow?