Engine/Transmission (1998.5 - 2002) New VP... 3 cyl idle

[KWilkinson]

Well I just installed a reman VP and lift pump in a customer's truck, fired it and it's only idling on 3 cylinders. It ran long enough for me to assume all the air is bled out of the pump and lines. Cleared the origional Inj. pump timing failure code and no codes returned. I had no snags installing this VP... it was the easiest install I have had yet. I checked the keyway 3 times during install to make sure I had it right. Think there is any possibility of the gear turning on me? Maybe a bad reman pump? Any ideas would be helpful... I will double check the keyway first thing in the morning.

 

[obert]

Its a streach, but what if one of the plungers in the head is bad. That would cut the same 3 cyl's evry time, right?



Maybe the ECM thinks its really cold out and needs a blanket. :-laf

 

[BradyWilliams]

Check to see if you have some stuck injectors. Dirt can be introduced when the high pressure fuel lines are off. Combustion pressure pushes up the fuel line and causes air in the pump. It would be very hard to get 3 cyl. to not deliver fuel and make it across the test stand. One stuck plunger would only cut fuel delivery in half not cut out three cyls. completely. I don't know how long you have ran the truck but I have seen some trucks needing to run a little longer to purge all the air out. Thanks

 

[KWilkinson]

I can pretty much rule out injectors, dirt, or air in the lines because it is not the same 3 cylinders every time (doing injector kills doesnt change anything) The keyway is in... I have a new pump coming in for our stock order and I'll stab it tomorrow... if it doesnt fix it, i guess i will tear into the front cover and make sure that gear is still in time.

 

[jwdeeming]

I just had a remanufactured VP44 only partially fail after a little more than a month, and the symptom was similar - would start but had a really rough idle. Failure probably was triggered by the failed lift pump.



Mine threw a 0216 one time, but when I cleared it and ran it again, it would not throw another code. It finally died completely while I was monkeying around loosening injector lines trying to figure out which injector was suspect, as someone else mentioned above.



I hope that's not where you're headed, but it happened to me...

 

[obert]

cut fuel delivery in half

So that's a 6-lobe pump, then? Dont think Ive evre had a boby bosch dist. pump apart. the old roosemaster's had three lobes, only onle plunger moved at a time.