24v Problem

307diesel

307diesel

built 6.7
Joined
Apr 7, 2010
Messages
426
I've got a 00 in the shop right now that's throwing us for a loop. I searched already and couldn't find anything. The guy called said his truck wouldn't start, after looking at it, it looked like the normal, injection pump quit(truck has 202,000 on original injection pump somehow). So we put a new pump on it, got it bled out, and it still won't start or do anything but crank. It's sending fuel to the injectors but doesn't seem to have enough pressure to pop the injectors. Ive been through all fuses, and relays. The truck has an Edge Juice so we unhooked it, still no change. My scanner showed that the tps is working correctly so thats out. I swapped the ecm with another known good ecm from another 00 auto, still nothing. Then yesterday the owner told me that the key fob quit working at the same time that the truck died. This truck is a sport with leather. I was told that it may have the security system and it could be causing this thing not to run. If someone could point me in the correct direction on what to test next and maybe how to test it, i'd really appreciate it. At this moment i'm at a brick wall.
 
Stock lift pump? Mabey check to see how much the lift pump is flowing in one key cycle. Just something to check.
 
Im tryin to think what is should flow in a key cycle. I was thinking it should fill a 2L bottle in a key cycle. Thats taking the banjo bolt out to measure it at the pump.. 9psi while cranking sounds low to me but its been awhile since I have messed with a VP44.
 
although 9psi is low, it's enough to start the truck. Sounds like something electrical to me
 
have you checked the o-rings on the connector tubes? If so, and you're sure there are no leaks in the system causing a loss of pressure at the injectors, start with the wiring. Really sounded like an ecm to me, but you say you've already tried a known good ecm.
 
It's getting lots of flow to the injectors just not much for pressure. And a stock lift pump keeping 9 lbs while cranking is good, since when cranking the vp is using some of the fuel it's receiving and there is a draw on the batteries at the same time, and how many will start and run with 0 fuel pressure? Most of them will for quite a while before they crater. Since the the key fob quit working at the same time, i'm suspicious of stock security system that i've been told comes with the Laramie models. But have no idea how to figure out if that is the problem
 
I don't think this issue has anything to do with the cross tube o-rings. The truck was running in the the guys driveway when all the sudden just died. Also like i mentioned before the injectors are getting fuel but when bleading the lines there doesn't seem to be enough pressure to pop the injectors. Seems to only have the same amount of pressure that the lift pump is supplying.
 
You need to invest in a VP44 cut out tool. Priceless. It's the best way to isolate the problem, and fix it without spending big money guessing.

Have you checked power supply to the ECM and what not?
 
gotcha, i had to go back and read. Sounds like the hard parts are good to go. I'm not sure about the security system, but i'm wondering if it may be taking a big draw electronically. Don't know if hardwiring the lift pump to a key on hot source would help or not. I'm just throwing out ideas here.
 
I do appreciate any input, i'm stumped right now... It just seems too ironic that the same time it died that the key fob quit working, and since they told me that i've sat and waited for the little red led on the bottom of the mirror to light up, and it has not. Not sure if any of those things have anything to do with it.

Yeah I'm sure that a p-pump would be the best but, it's not mine. I have not checked power to the ecm, i'm assuming it's good. The edge monitor is showing every thing like throttle position, coolant temp, etc. And since it gets that info through the data link i'm assuming that the ecm has power, but i've been wrong before.
 
what type of scan tool do you have? is it a code reader or scan tool? if you have a scan tool you should be able to get into the security system to check for codes.
 
the shop i work at has a modis and you still should be able to get into the bcm to check for any security codes.
 
Depending on your scan tool you're only accessing the Chrysler ECM. If you're getting companion module codes then you need to get a DRB and find out what codes are in it. Also what key fob do you have? Since the tipp module didn't come out until 03 the security system on these trucks (as far as I know) only controls the locks and is usually tied into the crank or in a 2000 a cam sensor for the security/ remote start system. I'm assuming since you didn't mention a remote starting system it doesn't have one. You're sure you have a cam signal? Does your tach work? And what code did you have to make you replace the pump?
 
I'm not getting any codes of any sort. Just has the typical remote for a 24v. No remote start. Tach shows about 100-150 rpm when cranking. Changed the pump since the old pump didn't have pressure at injectors. Once we pulled the pump we turned the shaft and it had lots of rattling in the pump. I've had a few pumps quit with out codes. This truck was ran with 0 lbs of fuel pressure for who knows how long before i bought it. Within 12hrs it had a new lift pump. Then i sold the truck. The current owner has had this truck for 8 months no problems. We've been waiting for the pump to crater since the day i bought it.
 
Bad vp??

I went through 2 new pumps before saying F it and tearing it down for the swap. I found a rubbed wire around the area of the stock lift pump that i believe was causing all my ussues. It was tied into the edge.
 
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