Engine/Transmission (1998.5 - 2002) Tough starting,Fuel pump question?

[ESims]

I have a 99 with 235,000 on the original vp-44. When i turn the key to start the truck the lift pump doesn't cycle on. If you leave key on without cranking it after 5 to 15 seconds the lift pump cycles and the wait to start light comes on. I changed the ecm thinking that it was the problem but it seems no better. Even though the injection pump is original the truck runs great once it starts. I have a mechanical guage and it runs at 15 psi and it pulls down to 12 psi when the comp box is turned up and i am wide open. Also the asd relay clicks as soon as the key is turned on even as the fuel pump is quiet. Any ideas??

 

[ALepley]

Sounds like you have a relay or switch not sending power when it should as soon as you turn the key. Check for corrosion at the pdc under the hood.

 

[ESims]

whats the pdc ??

 

[FourBarR]

pdc is the black box just aft of the left battery. Open it by eleasing the clips . Inside are the relays and fuses. there is a schematic on the inside of the cover showing the various items. Hope this helps.

 

[ESims]

thanks i didn't know it was called that. i was allready in there changing relays around to make sure that wasn't the problem. what tells the lift pump when to run?

 

[Sticks]

IIRC - ECM controls and powers the lift pump, no relay in the PDC.

When you go to KOEO (Key On, Engine Off) do all the normal lights in the dash come on, along with the chime, or is there a delay on those as well?

I'd be leaning towards an ignition switch if not.

 

[ESims]

all the lights come on with the exception of the wait to start light. when the wait to start light comes on the lift pump turns on for maybe 1/2 of a second then if i hit the key after this sometimes the truck starts instantly and sometimes it spins for 5 seconds or so then starts.

 

[Nschroeder]

Did you ever find the solution to this problem? My truck is doing the exact same thing and I am not having any luck finding the problemb



Nick

 

[ESims]

I put in a switch that turns the lift pump on and off. You turn off the pump to start the truck then turn the pump on. I also saw where people put in relays to do the same thing but the switch was easy

 

[BEnglish]

I had a similar problem, the truck would just turn over and not start till the WTS light came on and I heard the LP bump. On mine it took around 15 seconds till they did come on.

It turned out my ECM was bad and a replacement fixed the problem.

I did however have other issues that also pointed to the ECM to help with my diagnoses.

 

[Joe Mc]

I wonder if jogging the key (turn to start for 1/2 second) would force the "Wait to start" sequence to work? I know jogging the key will run the LP for around 30 - 45 seconds.

 

[Nschroeder]

ecm would also explain some of my other electrical gremlins.



I had a new one today, when my truck would try to ramp up to high idle it would kill and not restart until i disconected the batterys.