i got a 88 v6 pickup, i went muddin and hit a hole that was too deep, and water got all in my motor, i pulled the plugs and got the water out and put new plugs in. but the truck would not start. i put a jumper to turn the fuel pump on all the time and the truck started but ran rich, i pulled the jumper off while it was runnin and i started runnin fine then lost fuel pressure. Would it be a fuel pump relay or the open circut relay, or somethin to do with the pump it self..

 

probably water in one or more of the electrical connectors. maybe TPS or AFM. Could also be, since water got sucked into the intake, the AFM itself is sticking or otherwise malfunctioning.

 

all connections are good and the sensors are fine

 

what is the AFM?

 

air flow meter, sits on top of the air filter. measures incoming air and turns the fuel pump on when the engine is running.

 

its unhooked from the truck and when it was hooked up it did the same, will haveing it unhooked hurt anything

 

having it unhooked should cause the fuel pump to not run. so if disconnecting it didn't change anything, I think you've narrowed down your problem quite a bit.

 

when i hooked the jumper and mass air flow up the truck will not run but when the mass air flow is un hooked it will when the jumper is in.

 

thanks 4 your help and im lookin forward to buy a 400 dollar air flow sensor.

 

jumper? you mean to manually activate the fuel pump?

makes sense- the afm turns the fuel pump on when the engine is running and it is working properly. and it also sends a signal to the ECU about how much air is entering the engine. if you have the AFM connected, and it is malfunctioning, it won't be sending the proper signals to the ECU. When you disconnect it, and have the fuel pump jumpered, the ECU defaults to a fuel map based on throttle position and engine rpm, so it will run.

spray some FI or MAP cleaner into the AFM opening (take it off the truck first, of course) and see if you can get the flapper inside moving with your fingers. then hook it back up.

 

not so fast...!!!!!

try what I suggested above first. if that don't work, don't give up. I've got maybe another suggestion.
and you may get more tips between now and "throw in the towel" time.

 

the flapper does move, and ima go to buy some of that spray. i believe it has been not working properly 4 some time because of my fuel mileage ive been gettin 14mpg after i rebuilt the motor 6 months ago

 

if you realize that the flapper responds to the pressure of the air moving through the meter because of the engine sucking that air in, as opposed to your finger pressing on it, you might understand how sensitive it was to be and how much some mud that gets up there can affect it.

 

Found out that that was not the problem in side the acutuall maf computer mechanism there were broken parts. ill try to find one a junk yard or get a new one.