Engine/Transmission (1998.5 - 2002) Hard starting

[dlamkey]

VP 44 pump

2001, 5speed trans ,fuel pump upgrade to Raptor lift pump. Can someone tell

me the symptoms of a failing VP 44... . My truck has 112000 miles and sometimes is difficult to start when warm.

 

[LNaugle]

there are many symptoms... . try being a lil more specific and we can help you...

 

[dlamkey]

Cold start it fires up normal after its driven and really warmed up you have to crank

quite a while usually it doesn't start then until you cycle the pump and crank it again

then it will usually start.

 

[cerberusiam]

That is a typical symptom of the VP44 not liking a lot of inlet pressure when warm. The fuel control portion of the pump is getting weak and the inlet pressure doesn't allow it to open correctly.



Are you running the LP of the ECU like stock? If so there is a flash to only run a few seconds on startup so it doesn't create too much pressure. Even that doesn't work correctly all the time and one may need a button to shut off the power to the LP when warm.



Whne it is warm and hard starts try disconnecting the LP to see if that helps.

 

[dlamkey]

Thanks for the info cerberusiam. I'm running a Raptor LP set at 12 pounds pressure. Is it

possible to put a switch in the hot wire going to the pump? I'm new to this kind of stuff

and have found the TDR and its members a lot of help.

 

[cerberusiam]

Yes, put the switch on the ground side of the circuit not the load side. Did that on our 01 and it solved the hot start problem in the warmer temps.