Engine/Transmission (1998.5 - 2002) LP manual control?

[KenHokie]

I ran into a problem while adding a Westach FP gauge to my truck this weekend: Lost the prime in the fuel system. After much bleeding of lines and cranking, I got it to start . The good news is that my LP is working. This experience gave me an idea. Has anyone hooked up a manual switch to energize the LP without the need of bumping the starter? I would think that such a switch would be very useful for priming the system after changing the fuel filter or anytime the fuel lines need to be disconnected and reconnected.

 

[CFAR]

No switch but I have a nice long wire with soldered ends I use to hot wire the lift pump while I pressurize the tank.

This is the only way I can prime mine, won't suck anything from the tank otherwise.



Also have noticed that I seem to get certain codes set doing this.

 

[KenHokie]

CFAR, where do you jump the LP? I assume from the battery positive to the connector on the pump?

 

[rashwor]

Here are my thoughts...

I too have thought about doing what you are talking about. I have hesitation in doing this because of possible feedback into the rest of the electrical system (ECM, etc. ).



My thought is to acquire a second plug that will plug into the lift pump and wire it to a toggle switch. Then, all you do is unplug the lift pump from the electrical system and into the plug on the toggle switch. Turn the switch on and run the pump till you get fuel. Then unplug the switch leads and plug back into the truck electrical system. Should be a sweet setup.



I have trouble getting my lift pump to run for 20 - 30 seconds by bumping the starter due to the hard-start TSB that has been applied to my truck (BIG MISTAKE and did not fix the problem).

 

[WOT]

Wouldn't it be easier just to pull the fuel transfer pump relay and jumper it there with a couple 3" jumper wires?



i suppose you could also buy a new realy and pop the cover off and force the relay closed - then you install when u want to run the pump continuously.



Just don't play with the ECM side of the relay!

 

[jmeehan]

I've had the same thought, I even bought the parts, I just haven't installed them yet.

I went to an electrical supply store and bought a Square D momentary contact push button, a normally open and a normally closed switch. I'm planning on wiring the N. C. switch in the factory pump hot wire and run my own hot wire through the N. O. switch. Then with the push of one button I can open the factory wire to avoid back feeding the ECM and feed Batt + to run the pump. With the momentery contact button I won't need to worry about forgetting the switch in the wrong position .

The parts were about $50 U. S. If anyone wants the part numbers I can post them.

 

[RADdodge]

A three pole switch would do that. In one position, the lift pump feeds from the ECM, in the other position, I would feed it from ACC. If you have a pusher pump, I would suggest an electrical setup like I did. You would also use ACC to power the fuel pump with the engine off. If anyone is interested, the schematic is with my truck pictures.

 

[CFAR]

KenHokie,



run the wire to the connector on the lp the terminal closest to the front of the truck, it has a rubber seal to keep out moisture but you can back probe the connector easily enough. As I stated in my earlier post you can get a code set doing this 0230 I believe don't remember. lp current incorrect or something like that. If you disconnect the lp connector and then turn on the key you will also get codes set.



I way away on business from 11/28/02 till 1/18/03 I disconnected my battery during this time, when I got back truck started right up suprisingly and all my codes were gone 1693 and 0230.