O6' Died

[duraman03]

Saturday on my way to the store the truck stumbled and then about 10 seconds later died at the stoplight. I could not get it started, so a friend came with a D-Max and pulled me off the road. I have the Quadzilla Rail/Fuel pressure gauge which is not the best but none the less it does give me an idea of what is going on. When I got off the side of the road and started looking over things I noticed I had no Fuel pressure when I turned the key on, as I usually get about 5lbs or so. I also have a BD inline fuel pump that runs in tandem with the factory. So after AAA hauled the truck home the next day I wired the BD pump to run without the engine running and when I turned the key on I noticed the factory in-tank pup was actually running which it wasn't when I was on the side of the road. After a few tries I got the truck started and pulled it in the garage. I noticed a bit of a rough idle and quite a bit of grey/blue/white smoke but not according to the tachometer, just could hearthe rough idle at the pipe. So I changed the fuel filter and it fired up with the same miss and smoke. Then a minite or two later it cleared up. But the fuel pressure was all over the place, I took the fuse out of the BD pump and the truck sat right at 3lbs of pressure. Plugged the BD Pump back in and it was all over the place. Fuel pressure is usually around 22-23lbs before the issue. What do you think? Is it the stock pump? Or the BD or the FCA? Fuel pressure sending unit is on the feed line to the CP3.

 

[duraman03]

Nothing, No ideas?

 

[JaredH]

I am thinking it is related to your stock LP. If I remember correctly stock lift pumps, at least on the VP44 trucks, do not have an internal bypass that the injection pump can pull fuel through in the event that the in-tank pump fails (thus inj pump failure related to LP pressure). However, not to worry CP3s are designed in some applications without a LP (ex. Liberty).

So, IF that is the case then the stock LP could be starving your BD pump for fuel. Maybe the stock LP was pushing enough pressure when >3lbs that it didn't starve the BD for fuel, thus the BD was not trying to "bypass" the stock LP. If a very erratic supply of fuel is coming from the BD I can only assume that it could affect idle (FCA).

To eliminate the stock LP i would recommend the new Vulcan drawstraw! I did the Liberty canister mod and then this cam out about a month later...
DrawStraw™ V HiFlow

Can anyone verify if the '06s have a "bypass" in the stock LP? Correct me if I am wrong. .

 

[JGamble]

Though different year model, I had the same trouble. I was driving home from CVS, roughly 2 miles. While I was waiting there, I noticed at idle the truck was misfiring at 0800 rpm. I went in to CVS not thinkin of anything. When time to go home, I fired her up, just glancing at the FP gauge, to notice I had NOTHING. This gauge is a pre VP tap. Not thinking, I took off, and when I hit road, I could only TOP out at 2200 RPM. I had to walk that sled home at 5 mph with blue/white smoke SPEWING out of the pipe, the motorists hated me... . lol... tree huggers. Well, I brought it to the mechanic, thinking the VP died, he tested the LP first. I have the HPFP from FASS, come to find out IT died. Replaced it, everything is fine..... my 2 cents... . PM if any questions... .



Kind Regards,

John

 

[AHill100]

duraman03, I had symptoms similar to yours. The previous owner of my truck had installed a Carter pump inline with the fuel line bolted on the frame. The factory in-tank lift pump was left in. I started having intermittent failures related to fuel delivery. Turns out the Carter was 'locking up" according to the dealer who troubleshot the issue for me. We took the Carter out and it has been flawless since.

I think the in-tank "push" style pumps and inline "suck" style pumps may not work well together. Your description makes it sound like when you remove the BD pump your problems go away.

Or, remove the stock pump if your BD is producing the pressure and volume that killer setup on yours requires.

 

[duraman03]

Yes, I took out the BD/Carter pump and everything seems fine. No problems for about 4 days. Thanks for the help. Time for a FASS!

 

[JaredH]

So you were running 22-23 psi before you removed the BD/Carter pump ... What are they now? How is the factory LP working?

 

[duraman03]

It is running between 7 and 8 lbs now, but it doesn't matter anymore since I have my new Fass 150gph sitting here to my left!