Trouble Diagnosing Lift Pump

[fdfbuilds]

My lift pump (Raptor 100) is not coming on...the idiot light came on just a mile away from my home so pulled in the driveway to check it out.  Not hearing the pump cycle when I bump start.  Did not see voltage on yellow wire or illuminate a test probe light during 25 sec bump.  Truck starts and idles (from little lift pump in vp44?).

 

I'd like to test continuity from the ECM plug to the lift pump but don't know what pin hole is the right one? Or any other suggestions?

 

Really appreciate some help!

 

Thanks,

 

 

[mopartechnician]

Most likely you have the bad seal in the raptor and its fried. Call pureflow with your serial number and they will send you a new one.

Before you do that, make sure you have a power and ground to the pump. Also check the fuse for the raptor

Your vp doesnt have a pump inside (cp3s do). What is happening is there is a vacuum created in the vp that will pull fuel. Once you break that vacuum, no more running pickup

Edited January 8, 2014 by mopartechnician

[fdfbuilds]

Thanks for the info! Not finding a fuse for the raptor...the chilton's wiring diagram looks like power for the lift pump is coming directly off the ECM.  Is there in inline fuse or?

[mopartechnician]

Is your raptor on the side of the block on back on the frame?

[fdfbuilds]

Th raptor is mounted on the frame.  Found a blown 25 amp in-line fuse between the PDC and a coil mounted near the PDC.  Didn't have a 25 amp but a 20 amp put power back to the pump location...once pump was plugged back in it still did not cycle on.  Does that give more weight to the raptor being fried?

[mopartechnician]

Make sure power is getting back to raptor. They will ask you. That fuse and the relay it runs to is for the raptor. Listen for a click in that relay to know if its turning on

[JAG1]

 before trying the pump off the ecm I would run two wires directly off the battery to the pump instead, to see if the pump is good.

 

I know Mopar Mike says that certain conditions in a bad pump can hurt the ECM......... is around 600 bucks to replace.

[fdfbuilds]

Went back and checked to hear the "click" and I did but the raptor did not come on.  Will double check again and call Pure Flow in the morning.  Read somewhere to check the resistance accross the pump too: should be between 0.2 and 200 ohms on a stock LP, think that might be true of the raptor also?

 

If I can scrounge up some connectors and an inline fuse I'll try to direct wire the lift off of 12v too.

 

Really appreciate the feedback!!!!