I'll try to keep this a concise as I can- Any advice or thoughts will help.

99 5.9L 24v 5 speed 2500 4x4

I run an Edge Juice with Attitude CTS. Notice the fuel pressure at the filter was 8psi at idle and down to 2 or less under load. CTS quit working and about the same time (+/- a day) the truck started loping (like a gas engine missing or out of time) on start-up. I could recrank several times and get it to run smooth. Had codes pulled (because CTS not working)- VP44 timing, MAP sensor error, lift pump (all I know I now know I should have asked for the specific codes).

Replaced lift pump with a FASS Titanium yesterday. Had trouble with bleeding the injectors: bumped the starter several times till I had fuel flowing out of the feed line, attached feed line to VP44, cracked 1 & 3, bumped starter, then took three times cranking to get fuel to injectors. On the fourth time truck started, ran for 3-4 seconds. Tried to start again but only turned over with no fuel coming from injectors. Took about 12 more attempts at starting before I saw fuel and then it started immediately. Tightend injectors, truck smoothed out and idles just fine. Truck idles great, can rev to 3K RPM with no issues but once in motion/under load engine cuts out over 1500 RPM, once under picks back up again.

Also about the same time as previous issues arose, on cold mornings the heater grid drains my batteries before they finsh cycling- had charging system tested and alt and batteries good.

Edge Tech support can find nothing wrong with my unit (updated 3 different times), they sent me new cables- no change. OBDII port is working because dealer was able to pull codes.

Here is the question- Without the CTS and charging issues I would say the VP44 tanked. But I dont believe in coincidence- could I have an issue with the ECM causing all issues?

What about the MAP fault?

 

Update- I bought a code reader and the truck is throwing the following codes: P1687- No communication between the ECM and injector pump module. P238- MAP Sensor Voltage too high.....Any thoughts?

 

You'll be a lucky dog if your VP isn't fried.

7psi of lift pump pressure is enough to keep your VP supplied with fuel. You need more than that. Now, I know the fluid engineers will say that pressure doesn't equal flow, but without measuring actual flow you can use pressure to gauge where you're at.

The fuel going to your pump is what keeps it alive. Too little fuel and the pump gets hot - the fuel cools it - and the electronics fry.

So if you were only running 2 psi under load, you were doing damage.

Now it's possible that you've got a different issue, basically you're going to need to follow the diag tree for each code and see where you end up.

 

Horatio102,

Thanks for the feedback. I am fairly certain the VP is toast but I am wondering if the ECM isnt to blame as well. Just not sure how to figure that out. I am getting 15psi to the VP as of now so I know I have enough pressure to the pump. Idles like a champ but cuts out over 1500 rpm's.

 

Update- Turns out I had a faulty ground that was causing the MAP and fueling issues. CTS is still down so I guess the timing of it all was indeed just coincidental. Just an FYI, the Tech Department at Thouroughbred Diesel (where I had purchased all of my after-market upgrades) were life savers. They walked me through step by step how to diagnose and pinpoint my problem down to the exact pin to check voltage on etc.

 

Awesome. Glad to hear you're getting answers.