Fuel pump question

[red900]

Hey guys, Im sure you guys have talked about this too many times... But, I am doing the fuel pump change on my 95 R/T because of the check valve problem. Now I have it all out and the new pump I got from "Mr Fuel Pump" on ebay is just the pump, it is not the entire assembly.

My question is; Is the check valve inside the fuel pump itself or is it some piece of that entire assembly?

By the way, my replacement is a BOSCH - In-LINE
0580254979
260LPH
Max psi - 170
http://www.fiveomotorsport.com/FuelPumps.asp

 

[Tom F&L GoR]

There is an internal check valve in the pump (ensures the pump remains filled, since the fuel is the coolant and lubricant and that no sparks occur) and one in the top of the module. The one in the top of the module is supposed to hold fuel in the line, and depending on when you measure this, it can be from 0 psi to 49 psi. Zero is not necessarily bad as long as the line remains full, since the pressure will come up instantly once the pump runs again.

If you get the 1992-1996 parts manual from http://www.mopar.com/viper.html and look at figure 14-510, it's item 10. In later years, this parts is not available separately and the images make it look like they don't exist anymore.

This isn't timely information for you, red900, but I have a fuel pump primer timer relay that extends the time the pump runs when you first turn the key. If your check valve leaks, the pump has to refill the line before the engine sees fuel. This can take 6-8 seconds of continuous running. Unfortunately, the PCM only allows the pump to run for one second before cranking, and then only intermittently while cranking. Therefore it takes an embarrassingly long amount of cranking, or you do the key-on, key-off thing. The new relay simply runs the pump for 10 seconds continuously before handing over control back to the PCM and you can wait, crank, and/or start during this period. (If you really want, the time is adjustable.)

There are images of it in are in my picture gallery.

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[Chris1]

Tom: Is the fuel pump relay timer available for purchase? I see you instructions for it, however I'm not sure if there is a place to get on for my 1996 RT/10 McViper; let me know when you get a second if one is available.......

Thanks, Chris.

 

[Tom F&L GoR]

Chris, I make them. PM me with your address and we'll fix you up.