mfd115

back from work and got to look at it again. Fuel pump not working. fuses are good and relay is good but does not click when key is turned on. the powertrain relay next to it does and is an identical relay so I swapped them and both are good. I'm thinking that the fuel pump is bad or maybe the computer is. Any ideas. The fuel shutoff in the kick panel on the passenger side inside the cab is ok also or at least in the down position.

jprevat

iTrader: (1)

Drop the tank enough to get to the wires and see if the pump is getting power.

Jbrew

Did anyone mention the hammer yet? You can try beating on the tank KOEO. It may come back to life while doing so. Make sure the key is in the run position tho...only way. IF the pump energizes, -charges the line you'll definitely hear it. That being the case, - pumps bad (verified). Yea, pumps won't lock up (specially in 2 months time) like that unless they are very close to fail. They can freeze up intermittently causing intermittent problems in the end... Lock up then free up until it's completly toast.

truckfun21

Your title says it won't crank or are you saying it won't turn over but that being said I like to start with the battery and check voltage.

Jbrew

They mean the same thing lol.

Crank and Fire.

mfd115

Sorry, it cranks over just wont fire and run. I think I have narrowed it down to not getting fuel (gas) to the injectors. it's either no power to the pump or a bad pump.

mfd115

I'm going to try the hammer technique this afternoon. If that doesn't work I'm going to drop the tank to see if I'm getting power to the pump. I'm leaning towards the PCM being bad and having to replace it. found one online, flashed to my make, model year and everything with only having to have the keys programed by a locksmith.

jprevat

iTrader: (1)

Can you post a link to this? My KAM circuit is losing power every time I turn my truck off.

Jbrew

You most likley cleaned all the grounds and cable connects already. But that's what I had to do when my KAM kept resetting. I think it was the ground hiding in the corner of the firewall, close to the battery. That's the PCM ground. It's right in the corner, just a small wire lol.

Jbrew

BTW, you need to remove the battery to get at it.

NOTE: I'm not saying this is the problem, it could be. PCM/KAM capacitor discharge could be a result of one of many grounds at fault. The PCM uses more than one. Some information circuit grounds route differently, but thankfully, they are easy to get to and maintenance. I know where they all are from memory...some things you don't forget with these old trucks lol.

Anyway, - mfd115, jprevat, - hit the grounds before looking elsewhere, even if they look alright. Take the paint right off, clean the connector, bolt then cover them back up with paint/touch-up.


BTW- Most cab to frame grounds go missing with these trucks.