no fuel tbi ::solved

[Irish_Alley]

Well I bypassed the switch gauge still didn't move. Maybe its the valve ? I have another off my buddy's 90 but its unknown condition

[Irish_Alley]

Got to thinking about it. If I bypassed the relay and the pump turned on and got fuel it should stayed running via the oil pressure switch after I unhooked the jumper wire. And the right side tank was the side that was running and its the 1/8 full side.

[DnStClr]

Irish are ya throwing any codes from the ecm?-- You can send 12 VDC directly to the fuel pump through Terminal G of the ALDL connector under the dash.

[Irish_Alley]

never bothered to look for codes lol. i know the light works but i didnt even look. i knew the g post un the aldl went to the fuel pump but didnt think it could handle the amps or the real reason behind it

[Irish_Alley]

once i get a bay in the shop clear from the paying jobs ill bring her in from the 32° weather and rain. then ill start with double checking fuses cause now i cant even bypass the relay. then move to what bd said to check for. i really dont want to but i do have a stand alone tcu for the trans and i might put on a carb and distributor and be done. but this is y first tbi in a square and i wanted to try to make it last. but once i go with the cummins i have to do the stand alone anyway

[DnStClr]

That can help determine if the pump has failed. disconnecting the fuel line at the throttle body will help check for flow.  You don't need ignition on for this check.
 Also, the temp sender next to the thermostat can fail and affect the ecm sending a signal to the injectors to pulse.

[Irish_Alley]

theyre getting pulse i checked that with a diode. i have never heard the pump prime before, the pumps both tanks have only worked once the truck was running.

[Captkaos]

Are you listening to it or having someone else listen?  Are you using the red jumper at the relay just adding power to it?
Have you tried shaking the harness and see if there is as short or broken wire.  If you get the TBI running you will not want to convert to carb...

[Irish_Alley]

got it . i think like bd said it was two problems maybe three. what i did was jump the wires like bd said and took apart the bulkhead tested on the inside of the outside piece and i had 12v with or without the jumper??? then i moved to the switch took an ohms tester to it the switch would work 100% one way and 50% the other sprayed some brake cleaner in it seamed to help but wasnt 100% when you switched tanks.

so i took it apart and scrubbed the grim off the brass and put it together and it worked 100%. put it all back together and turned the key to on, and i heard one pump prime. waited 10 seconds switched tanks and the other side primed not to mention the gauge works again. i think before when i tried jumping the relay i had the switch either disconnected or it was on the bad side so it wouldnt prime or run.

[Captkaos]

So you're good now?

[Irish_Alley]

yes between bd (pumps priming) and you (tank selector switch) we got it figured out
thanks guys

[VileZambonie]

Don't forget your truck probably has the fuel module in addition to the ECM controlling the fuel pump on this truck.

You should probably verify the fuel pump relay is functioning and that you are not simply being energized by the oil pressure switch. Disconnect it and check to ensure the fuel pump relays is functioning on it's own

[Irish_Alley]

so the pumps priming for 5 seconds isnt the fuel pump relay working?

[Irish_Alley]

Well new problem took the truck and dump trailer to the dump. About 10 minutes down the road staying at a constant speed around 40, she just dies. Pulled into a drive way and parked her. Switched tanks still no start. Switched back starts up. So while running I switched tanks again and it stalls out. Switched back and she starts up. Took her to the dump dump the load and when leaving it does the same thing, Then starts right up. It stalls when I'm cruising not stopping or stopped. I'll see if any codes show

[Irish_Alley]

Code 54 flashed 3 times
54- mixture control (m/c) solenoid or circuit (carbureted models)
 54- fuel pump circuit (1986 and later models)