1991 d150 318 no start

[powers1861]

This is a long shot but I have a 1991 dodge d150 TBI 318. Everything runs fine except when I try to start it in the morning when it’s cool. No fuel to TBI. But when I get home and the temperature is warmer it starts 1st try. Been doing this for months. Any ideas as to why. I cannot hear the fuel pump whining in the mornings but in the afternoon I can.

 

[Daw14]

Bad electrical connection somewhere, when it’s cool the metal contracts on the contacts then in afternoon heat they expand , making contact again . Good luck locating the offending plug or harness.

 

[powers1861]

Thanks, I did a wire trace what a chore that was. Didn’t find anything. Resistance checked wires from connector to connector. Confirmed ASD relay contacts were closing. The ASD relay is in the scene as I have the mechanic manual with the TBI electrical schematic. I did get .2 ohms. The only weird issue was voltage downstream of ASD relay to fuel pump was 2 volts. Should there be full voltage going to fuel pump? Like I said the relay contacts are fully closing and with the relay removed, on the female connector I do have 12 volts but 12 volts is not passing through the connector. I believe all I measured was 2 volts. Not sure if voltage is increased during acceleration or not. I may have a bad female harness?? For the ASD. FYI where I measured voltage was at a solder connection underneath all the tape I removed during the wire trace.