wont start

[swamprat]

can i straight wire my fuel pump and vp44 to a ignition on circuit and bypass all the electronic crap so i dont get stranded any more?

[Mopar1973Man]

You'll have starting issues because during cranking the fuel pump is modulated at 50% duty cycle to reduce fuel pressure during cranking. So more than likely this is not the answer to your problem. But if the ECM is not supplying good power your most likely going to have ECM problem eventually...

[swamprat]

where is a good place to buy ecm, and i talked to blue chip and he said it could be a pissed off ecm due to aftermarket fuel pump installation, any ideas on that?

[Mopar1973Man]

Typically most all aftermarket pump have a control relay unless its one of the cheap factory replacement pump like FASS DDRP or simular. Not sure on ECM replacement but I know that the VIN number has to flash into it... I know Dodge gets there ECM blank and you must bring the truck to them and have it flashed.

[dripley]

i went the rebuild route on the ecm. the provider promised quick turn around in most cases. it took almost 3 weeks to get it back and it did not work. they honored the warranty but it took 5 weeks more for them to get it back to me. the whole while i am having to rent a vehicle to get to work. theyalso kept my core charge, they said my core was unrebuildable. six months later i am sitting on the side of the road with a bad ecm again. i spent a wad of money trying to save few hundred. i ended up getting another one thru a local mechanic form chrysler. the mechanic had the equipment to program the ecm. unless someone knows a reputable rebuilder i would never by another from anyone else. you can check here or some of the other forums and see if someone has one for sale, i am sure they can be reprogramed. with as many aftermarket fuel systems you can buy or put together yourself i dont think i read of one screwing up the computer. it is just a fuel pump.

[swamprat]

truck still wont start only now fuel pump does come on and stays on for appox. 1 minute after key is turned off even if i remove fuel pump relay!normally when the no start ocurrs the fuel pump will not come on.at least now i feel like i may be able to find the problem with a little help,all the times in the past i would wait a few minutes and it would start right up like nothing ever happened.its a pain trying to fix something that was working again.i dont understand why the fuel pump stays on after i remove the keys from ignition and remove the fuel pump relay! please any suggestions:banghead::banghead: thanks kenny

[volkswagon]

I'm no good with helping you with your last post but I can make an ECM suggestion. I just put in a rebuilt one from Go ECM. Works like a charm so far and it has a 1 year warranty. When I talked to them they only had 1 left after I bought one. They said they're getting really hard to find since there's so many failing.

[dripley]

the relay under the hood in the pdc controls the vp and not the lift pump. i believe the lift pump is controlled by the ecm. has your truck generated ny dtc's?

[Mopar1973Man]

the relay under the hood in the pdc controls the vp and not the lift pump. i believe the lift pump is controlled by the ecm. has your truck generated ny dtc's?

Correct... The fuel pump realy is the power supply to the VP44 NOT the lift pump on the side of the block...

[swamprat]

it hasnt showed any codes using the key switch method, but i dont have a code reader. i am going to check my wires and see where im losing voltage in the morning while its still bearable outside. 100 degree temps here in tallahassee and my truck is in the middle of the field.i will post my findings tomorrow. thanks for the help,kenny.

[gassernomore]

You will need to use a codse reader for your truck. Key method will not work on it.

[swamprat]

key method does work on my truck but i only get 1 p-done.checked voltage to vp44(pin7) and only had 3 v.checked ground (pin6)had continuity.i did not get to check voltage at relay because it started up, so i guess im handicapped again because its hard to fix something thats working. is it hard to open up the pdc?thanks kenny.

[flagmanruss]

When my truck quit, I got no codes in the window with the key trick... but the diesel shop got 4 codes with a code reader.

[gassernomore]

key method does work on my truck but i only get 1 p-done.

Thats the problemm with that year of truck. You should be getting "done" twice. Maybe your not waiting long enough for the second done. The code is only from one computer. You could still have codes in the other computer.

[dripley]

key method does work on my truck but i only get 1 p-done.checked voltage to vp44(pin7) and only had 3 v.checked ground (pin6)had continuity.i did not get to check voltage at relay because it started up, so i guess im handicapped again because its hard to fix something thats working. is it hard to open up the pdc?thanks kenny.

my pdc has 2 tabs, one on each side. just squeeze them and lift up. the pdc is just behind the drivers side battery on my 02.

[flagmanruss]

I got "done" 2X no codes. The dealer claimed "no codes" but I don't trust them to have used the code reader as they missed the electrical issue & jumped to the Failed Fuel Pump diagnosis. As I posted at the time, Diesel shop got 4 codes. I don't understand it but there it is.

[swamprat]

i am going to shiver diesel tomorow and see what they say. one thing i have learned about these truckes is that there is alot of guessing. but maybe they can find some codes that may relate. i just wish my truck had not started acting normal. it is hard to trouble shoot something that runs good. one week ,two weeks i will be stuck somewhere again.but i will hotwire the vp44 and go home!thanks kenny.tallahassee florida.

[Mopar1973Man]

Here is the wiring for both the VP44 and the lift pump...

VP44 Wiring... Take notice the fuel pump relay on top here. This is to supply power to the VP44...

Now take notice to the ECM has to + power leads heading towards the lift pump but there is NO relay in the circuit. But it relize on the driverside ground for its connection too.