dont hear fuel pump

Reply Subscribe

Thread Tools

Search this Thread

May 24, 2006 | 10:09 PM

#46

openscars

Thread Starter

Junior User

Joined: Jan 2004

Posts: 66

Likes: 0

well we tried hitting the tank and still dont hear anything we only hear the pump on the frame rail. he's getting me a in tank fuel pump at cost so he's hoping it will solve this tiresome problem i'll update tommorrow after i put it in

May 25, 2006 | 02:51 PM

#47

openscars

Thread Starter

Junior User

Joined: Jan 2004

Posts: 66

Likes: 0

well we replaced the in tank fuel pump and now we can hear it running. the fuel pump doesnt turn on for 3 seconnds when you turn the key but the truck will start. it actually idles better than it did before. well if you floor the throttle the engine wants to diebut will run if you tap it lightly. we then looked at the relay the truck will start if the fuel rail fuel pump is not on as soon as we turn it on the engine dies. anybody have any ideas like ive been hearing im going to buy a fuel pressure regulator and maybe we'll see what happens.

May 25, 2006 | 06:21 PM

#48

openscars

Thread Starter

Junior User

Joined: Jan 2004

Posts: 66

Likes: 0

well i just finished replacing the fuel pressure regulator and the TPS and im still shooting black smoke and running rich any ideas now??

May 25, 2006 | 07:16 PM

#49

87 XLT

Postmaster

Joined: Oct 2003

Posts: 4,516

Likes: 1

From: SoCal

OUCH, what a PITA this has turned out to be.

The thing that bothers me the most is that you could'nt even get an 11/"system pass" code from the computer.

And how is it that the pumps are not priming for 3 seconds, but it does start???? The computer is supposed to ground the pump relay for 3 seconds & once it's started ignition pulses tell the computer to ground the relay nonstop.

At this point if this was my truck I would tow/drive it to the nearest GOOD independant shop & the first thing they should do is figure out the no trouble codes thing.

May 26, 2006 | 02:40 PM

#50

openscars

Thread Starter

Junior User

Joined: Jan 2004

Posts: 66

Likes: 0

so i decided to go to a junkyard and find a computer. well the only one that i knew was working was out of a manual not auto. so i picked it up. i figured i would ry and see if i could get codes from it. well i hooked it up and jumped the fuel pump and the truck ran smooth and not black smoke and no smell of gas. i pull the codes form KOEO and got code 87 and 95
87 - Primary Fuel Pump Circuit Failure
95 - Fuel Pump Circuit Open - EEC Processor to Motor Ground

So where should i go now besides getting a new computer??

May 26, 2006 | 03:45 PM

#51

openscars

Thread Starter

Junior User

Joined: Jan 2004

Posts: 66

Likes: 0

can someone tell where the orange ground wire from the computer goes to?? im thinking thats the ground to the motor but am not sure.

May 26, 2006 | 06:27 PM

#52

87 XLT

Postmaster

Joined: Oct 2003

Posts: 4,516

Likes: 1

From: SoCal

Yeah, orange is a ground wire, but take a look at computer pins 40 & 60 on your wiring diagram. Those pins are wired to a splice which is wired to a ground on the engine along with the negative cable from the battery.

If you run a jumper wire from pin 40 or 60 to the negative post on the battery & the pumps run, you've found your problem

May 26, 2006 | 08:17 PM

#53

openscars

Thread Starter

Junior User

Joined: Jan 2004

Posts: 66

Likes: 0

thats what it was the orange wire was disconnected. the truck started up fine and took it for a ride and she was smooth with no problem at all. I appreciate all your help. thankyou!