So my fuel pump is getting power, but wont kick on. Its a walboro 255 running to 550/750cc injectors on a large rotary doctor streetport. The car itself is an 89 TII. I pulled the lines from the filter and pump both, turned the key on and even tried cranking. Its just not kicking on. Tested the input connectoe to the pump for voltage, its good. So whats the next step? Btw, its an rtek2.1 ecu.

 

The pump will run With the Ignition Switch ON if the AFM is moved in any way.
The pump will NOT run if the afm is NOT moved with ignition ON.
The pump runs on key to START position.
If your Afm is disconnected you won't get the pump to run.
IF you jumper the fuel check connector at the AFM( 2 terminal Connector) you will get the pump to run,that is IF everything is OK.

 

Roger that. Ill give it a shot today. I checked continuity on the resistor relay last night as well. The top left/bottom left are only getting .1 ohms. So im wondering if the resistor may be the culprit.

 

Another update. Double check the fsm and resistor relay. Its fine. Though when checking the fuel pump relay under the steering column my multimeter just searches for voltage. I checked it IAW the FSM. It just searched and searched. Bad relay? Lol

 

how does a multimeter "search" for voltage???

 

Look at the circuit opening relay. Top row far left wire should have voltage w/key to start. Wire next to it (top row middle wire) has voltage w/car running and key to on. When both wires have voltage when they should the Blue wire in the plug should have voltage. Blue wire powers the resistor relay which in turn powers the pump. At the circuit relay the bottom row far left wire is Black. This is a ground wire. It can be used by the multimeter when checking the voltage of the two wires (Black/White) and the Blue wire.

 

Thanks for the tip. Thats what i was talking about originally, i tried it different this time though, using the ground on the relay as the ground fir my multimeter. Im only getting about 2.5v to the top right (blue/red wire) with key to on. That may be because my battery is about outta juice. So its not the resistor, ohmd it out already. It doesnt seem to be the curcuit opener, and the pump is an almost brand new walboro 255, less than 1000 miles on it. Could it be the RTek2.1? Im out of ideas. I even tried jumping the test connector by the front passenger strut tower. Still didnt get a start up, but it was cranking slow and did sputter a bit. Ill try jumpering the connecter while a buddy jumps the battery tomorrow and see if it starts. If it does, what is my problem?

 

One more thing to add. I just ohmd the curcuit opening relay by the FSM. Resistance is good. So it should be operating correctly, right?

 

As Styx and I have stated, the pump does not turn on just because the key is set to on. You either have to jump the fuel check connector or open the AFM flapper for the pump to turn on w/key to on. Again, w/key to start the Blue wire will be powered. If the engine was running the Blue wire would be powered. W/just key to on the pump will not be activated because the Blue wire will have no voltage. The 2.5 volts you see is likely voltage that is bleeding through the relay from the B/W wire at the relay that has 12 volts w/key to on.

 

Right, i tried jumping the connector and moving the flapper both. The pump doesnt kick on. The 2.5v i saw was the only wire i got an accurate voltage reading at w/ key to on. What youre saying to do, just so i know im understanding correctly, is jump the test connector, turn the key to on, and check the voltage at the relay at the same time, right?

 

Correct. The top row center wire (Black/White wire) should have voltage w/key to on. If it doesn't then your 15 amp engine fuse is likely bad (found in the interior fuse box).

 

Turned out my 8 month old walbro 255 is bad..and after reading up on their warranty process ive decided to buy a new one. Itll be here sometime friday, so i can finally resart the tuning process to make up for the street port i just had done. Took me long enough to figure it out huh? Ill get there.eventually. im used to working on jet engines, not cars. Lol