No high pressure at vp when cold unless hotwired

[moparguy55]

Hi All 

I have searched high and low and didnt seem to find anyone with similar issue. Just bought a 2002 6 speed with an edge juice and fass ddrp lift pump rebuilt VP at some point. The issue is sitting overnight it looses prime between vp and injectors. Parked nose downhill so front bumper was a good 2 feet lower than rear. Same thing only low pressure fuel to #4. After muchhhh cranking dribbles at 1 and 3. It will eventually fire up like nothing happened no smoke. pulls hard on road absolutely no drive ability issues fp 13 at cruise on level 3 and 17-18psi idle.

Tried unplugging lift pump to test for bad diaphragm and it still didn't start.

Sits for 2-3 hours and insta fire.

 

Its at the shop now and they tried to start it after sitting overnight and same thing no high pressure at injectors. Fuel at vp inlet no air. They hotwired the vp and instant high pressure fuel at injectors. Plugged harness back into vp and boom insta start. They checked the pin thats not supposed to have any power only after the key goes off and all was fine. No codes either.

Ecm issue ? 

Is it possible sticky rotor in pump and that the power from battery to the vp is stronger then what ecm sends ?

 

Thanks

Edited January 6, 2016 by moparguy55

[Mopar1973Man]

3 minutes ago, moparguy55 said:

Is it possible sticky rotor in pump

If the rotor was sticky as you say it would of broke the plate in the pump and been dead period. (Part #19) This plate is what drives the rotor so if the rotor seized this plate snaps.

As you'll see there is a pin on the end of the shaft that mates to that plate.

3 minutes ago, moparguy55 said:

Tried unplugging lift pump to test for bad diaphragm

The diaphragm is no longer an issues with Rev 027 pumps its a steel plate.

Could you find a ECM to trade with some for a morning test? If you trade out and the truck fires right up the ECM has taken damage. In any case I would be looking at the alternator and testing for excessive AC noise.

[moparguy55]

Thanks for the fast reply Moparman.

 

Garage just called he unplugged the edge juice last night but the pump wire is still attached and fired instant this am.

So the edge must be defective. He put it outside its -15C today and hes going to try it again tonight at 5.

 

i did notice one time the edge screen was black said communication error or something when i turned key on during the cranking.

Edited January 6, 2016 by moparguy55

[Me78569]

Very interesting.  

 

I would remove the edge %100 and drive it around a bit and see if it is fixed.

[Mopar1973Man]

Rather common for Edge Juice modules to fail like that. Most of the problem is the module is out under the hood in the heat and weather.

[moparguy55]

Im kinda iffy on removing the wire tapped into the vp :S

I will drive it for a couple days and see what happens then plug the edge back in and see what happens. Is it worth sending it back to edge to get fixed ?

 

i will test for AC noise noticed its a new alternator on it but still could be defective.

 

 

Edited January 6, 2016 by moparguy55

[Me78569]

That is up to you.  If you don't want to spend the money and like how the truck drives without it, then I would say you not get it fixed, if you miss the power and have the money then I would say you fix it.

[moparguy55]

9 minutes ago, Me78569 said:

That is up to you.  If you don't want to spend the money and like how the truck drives without it, then I would say you not get it fixed, if you miss the power and have the money then I would say you fix it.

Oh i will want the extra power lol

I had a stock 01 HO and a stock 99 auto before. I sold an 04.5 HO to get back into the 24v as of all the dodge diesels i had i prefered the 2nd gen QCSB. Sold the 01.5 as it wasn't a sport. Looked for one didnt find it so i bought a 04.5

 

I can say after driving this 02 wow did i miss the 2nd gen. Level 3 down low it pulls as hard or harder than the stock 04.5 HO. All i want is similar power and with just the juice on the truck im content.

What i should have said is it worth repairing the juice or should i buy a new one, or a comp box, or ?

 

I like the idea of the built in gauges to monitor fuel pressure egt and boost.

Edited January 6, 2016 by moparguy55

[Me78569]

I would assume it is cheaper to have them fix it.  all edge boxes that wiretap have the same programming so the screen is the only difference.  

[moparguy55]

The edge bein the problem too good to be true.after sitting out in the cold all day no start. So somehow the heat has an effect to what not sure. Saga continues.

[tbo1450]

I've had no starts come in with the same problem. No start when cold. When it's gets in the shop, everything fine. I've put the PCM in the frezzer for a few hours and reinstall. To verify the bad module.

[moparguy55]

1 minute ago, tbo1450 said:

I've had no starts come in with the same problem. No start when cold. When it's gets in the shop, everything fine. I've put the PCM in the frezzer for a few hours and reinstall. To verify the bad module.

Kool thanks for the information. I will pass it on.

[Me78569]

haha I have done that before to recover a file needed for a client off of a failing harddisk.  

[moparguy55]

So the frozen ecm shouldnt start the engine if its culprit correct?

[tbo1450]

Yes. Shouldn't start. 

[moparguy55]

You had said pcm. Is it not the engine control module that runs the vp? 

[Me78569]

Ecm on the block controls fueling

[moparguy55]

Ok thats what i thought. Does anyone find it odd that there are no codes on the scanner ? There seems to be a list of like 100 trouble codes on these trucks and it doesnt trip a single one lol. At this point  I wish it would just trip a ecm or vp code id change the part and be done with it.

I have had over 30 vehicules in past 20 years and never got a really good hosing untill now. Be the last purchase sight unseen. Played some camera angle tricks and lied about a lot of things on this one.

Edited January 7, 2016 by moparguy55

[Mopar1973Man]

10 minutes ago, moparguy55 said:

Does anyone find it odd that there are no codes on the scanner ?

No. Because if the Edge Juice is internally shorted and the CAN Bus data is fouled then, of course, the ECM and VP44 will do weird things too. Edge EZ and Edge Juice have these issues because module being under the hood. Edge Comp is the only one where the module is inside the cab.

10 minutes ago, moparguy55 said:

 I wish it would just trip a ecm or vp code id change the part and be done with it.

Can't. Because there is no error code for a failed external module like Edge Products. You already found the failure by unplugging the Edge Juice and it starts and runs fine. So make your choice of what you going to replace it with another Edge Juice or Edge Comp but you'll have to buy gauges.

Edited January 7, 2016 by Mopar1973Man

[moparguy55]

16 minutes ago, Mopar1973Man said:

No. Because if the Edge Juice is internally shorted and the CAN Bus data is fouled then, of course, the ECM and VP44 will do weird things too. Edge EZ and Edge Juice have these issues because module being under the hood. Edge Comp is the only one where the module is inside the cab.

Can't. Because there is no error code for a failed external module like Edge Products. You already found the failure by unplugging the Edge Juice and it starts and runs fine. So make your choice of what you going to replace it with another Edge Juice or Edge Comp but you'll have to buy gauges.

Unfortunately it doesn't look like its the juice as it sat outside in cold all day yesterday and same no start with edge unplugged from the obd2.