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Archived ECM instead of VP Problems???? I'm hurtin here

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Archived No Brake lights no pass inspection

Archived new smarty=dead truck

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Okay now I'm really confused and frustrated!!!! You might have read my origional post "Dead VP... but what else. "



I finally broke down and took my truck to a reputiable diesel repiar shop. They got the truck running with a shot of ether and the same thing was happening... great running truck... . then dead truck. They are now telling me that it's the ECM that most likely caused the problem. My question is how can the ECM be tested? Should I get it flashed before I spend the 1300?



Here is what I wrote in the last thread that best describes the problems I was having:



As far as holding a prime at idle and wide open there was no problem except that I cannot test that now due to the truck not running. I do know that the FASS will kick on and has no problem building pressure at the filter canister.



As far as the amount of fuel in the tank. I filled up before installing the FASS on 1-26-08. 1-30-08 I installed the Edge with Attitude, with no problems after test drive (about 120-150 miles into the tank at 15 mpg and 17 mpg after edge, which I assumed is due to cold weather, but cold have been a sign of a failing VP from what I have heard. )



2-1-08 troubles begin. I might include some things in here that don't mean anything. I set the turbo cool down mode to 1 min to see how it worked. Went for a little bragging ride to show off my new power and when shutting the truck down hit the brake to stop the cool down cycle prematurely (after cool EGT's) for some reason the truck shut down strange.



After that I experienced hard starts, when edge was on 5 and 0, maybe I should have been more concerned about this. On my way home I got off the highway and at the end of the ramp I put the truck in neutral and that's when the pressure started dropping. Shut the truck off at 4 psi. I then primed the system with the FASS with no problems (15-17psi after turning the key switch to kick the FASS on. ) This happened two more times, never coming to a complete stop, but during a slow down (only one of which was a quicker stop. )



On the third pressure drop the truck died and that was all she wrote.



As far as trouble shooting that I have done.

-3 injector lines cracked-only one flowing fuel

-unhooked the edge except for the VP wire penetration

-fuel flows into filter canister at a high rate.

-fuel filter replaced same day as FASS install.

-no water in fuel

-fuel is not jelled

-as far as I can estimate I have about 10-15 gal of fuel which is the lowest it has been since the edge and FASS installs.



My guesses were.

-did the FASS loose prime, with the amount of fuel I see how this is possible, but I didn't figure it was probable because I hadn't had the same problem with the stock LP?

-Was the VP just tired and ready to go and is my only issue, if so how does this explain my pressure drop?

-Can the pressure drop be explained by the VP locking in a position at idle (problem with pressure only happened when I shifted to neutral slowing to stop) where pressure can not build in the filter canaster because fuel is being pushed right back to the tank?
 
Here's a little update. They're not 100% sure that it is my ECM, but 97% sure, the other 3% is some sort of VP failure. The truck isn't tripping codes when the problem occurs, and it occurs everytime the truck is run. In the mean time I'm stuck driving my old ford.
 
The VP can mechanically fail internally. There is a plate in there that rides on the top of the rotor with two screws... I have seen the screws back out.



How many miles on the truck? I've had to replace my ECM once too, but it gave codes. Any codes present?
 
85k or so. Something shuts down when I start coming to a stop from driving around. I don't know where the problem is, but the way I see it either some part of the fuel system is being shut down by the electronics for some reason or part of the fuel system is having a problem. What I don't understand is why will it idles just fine, but after a short run the fuel pump shuts down and the truck dies. The mech. said that no codes are being flashed.



The shop said they are waiting for an ECM that they know is good to see if that is what the problem is.
 
Here's my updated situation. They hooked up an ECM that they knew to be good, but problems on my truck still exist. I'm still thinking it's the VP, but I guess I'll let the experts figure it out. The way it's been going I hope they can get it running by the end of the month.
 
sounds like the wire tap on the box affected the solenoid bypass valve in the VP. Thats also how mine died but it was at WOT and then seized the rotor.
 
The strangest part is that the truck will run and has no problem at WOT. On the other hand it will not start on it's own and will die (I'm assuming because the VP and/or FASS shuts down) when returning to idle after a period of higher RPM (1500-2500). Now the shop is saying that it will run at idle for a while and then die, I'm assuming when it starts to get warmed up, maybe when it starts switching from high to low idle.



I thought with a dead VP the truck would just idle at most and nothing else. Why will this thing go balls out and not have a problem? Myself, I am leaning more toward the VP but I can't explain how well it runs when it does... until it dies of course. Could a sensor be bad that isn't popping off codes?
 
Now I seen both posts , what area are you in ?
Maybe some one can help or suggest a place if we new where you are ?
I would want to focus more on fuel pressures , only near the end did you give any pressure numbers , the 4 is way to low as I remember , and your description is too sketchy to tell , did you shut it down ? That is written as a statement ,like you shut is down .
Also I might figure that it may die at that pressure .
I would start over with all your testing , get pressure & conditions clearly stated , if not what they should be [ memory - never lower that 8-10 lbs WOT , 13-25 is best .
If not look at mechanical , pump / pressure regulator , then electrical / both power & ground , a bad electrical connection will look good but may not supply enough amps under load .
 
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