2006 Dodge Ram 3500 - Thor Project

[Mopar1973Man]

I'm pretty sure now it's a loss of prime. Somewhere in the crossover and injectors yet. I managed to get all set up a graphic display of rail pressure. The lift pump comes up fairly quickly to 14 PSI then the rail starts at 84 PSI engine off and key on. Now when lift pump hits 14 PSI quickly order the rail bounces from 84 PSI to about 1,1xx PSI continues to crank then the  surge hits at 12,xxx to 13,xxx PSI and the engine starts the pressure settles at 6,xxx to 8,xxx pulsing.

 

Changed the supply banjo seals on the CP3 and stopped a weeping leak. Then for fun pulled the fuel filter to look at filter condition and lid seal. Filter needs changing and the seal I changed from a salvaged seal. The crank time is greatly reduced but still could trip a grid heater light on only deceleration and its a 10 chime account again. The grid heater light can be reset.

[Mopar1973Man]

Here we go.

 

There will be lot more photos and article wrote. 3rd Gen article is building.

[Tractorman]

Whadda ya doin'?

 

- John

[Mopar1973Man]

9 minutes ago, Tractorman said:

Whadda ya doin'?

 

- John

 

 Injector inspection. 

 

I managed to get all 6 injectors removed. I'm going to town for a scotchbrite pad and brake cleaner.

[Mopar1973Man]

Update...

 

So i pulled all 6 injectors doubled checked the fitting of all parts and made sure all parts were of good condition. Now brake cleaned all parts and mating surfaces to bet sure everything was clean and job is done absolutely right. Now during reassembly I had the terminal post snap off the #1 injector and I'm going to have to send this one out to be serviced and repaired. Sadly I got a delay to fix one injector and already called @dieselautopower and talked to Mitchell and got everything ready to ship out tomorrow.

 

Temporary pause button on Thor for the moment... 

[Tractorman]

So, at this point it doesn't sound like you are seeing anything that would be contributing to the symptoms you are having - is that correct?  Bummer about the broken injector. 

 

- John

[Mopar1973Man]

Still the logics of the ECM is calling for high return rate possible misaligned injector / crossover tube not seating. This is why the grid heater light and chime. Which also part of loss of prime issue possible all relayed but need to finish and try starting but now wait for mail back and forth.

[Tractorman]

On 12/31/2024 at 3:58 PM, Mopar1973Man said:

The lift pump at key on rose to 14 PSI during grid heat. Then, during cranking, the rail jumped to 17,xxx PSI and continued to be hard to start. Now, I stopped and unplugged the FCA and tried again. The lift pump again rose to 14 PSI during grid heat. Then cranking jumped to 17,xxx PSI, and I also continued to crank until it started. The only difference was the FCA disconnected rail stayed max pressure where after starting with FCA would drop back to about 7,xxx PSI roughly.

 

The above post indicates that fuel rail pressure rises quickly to well above 4,500 psi, but the engine continues to crank a long time before starting.

 

On 1/1/2025 at 12:09 PM, Mopar1973Man said:

The lift pump comes up fairly quickly to 14 PSI then the rail starts at 84 PSI engine off and key on. Now when lift pump hits 14 PSI quickly order the rail bounces from 84 PSI to about 1,1xx PSI continues to crank then the  surge hits at 12,xxx to 13,xxx PSI and the engine starts the pressure settles at 6,xxx to 8,xxx pulsing.

 

This post indicates that fuel rail pressure stays well below 4,500 psi during cranking and the engine won't start until the pressure suddenly jumps above 4,500 psi.

 

Which post is correct?

 

- John

[Mopar1973Man]

Both really. It is random depending on how deep the rail drains out. I've left both the lift pump gauge hooked up and typically watch the live data tool. Again numbers vary based on how much the rail drains off. 

 

Those are two different run cycles showing the changes from one start cycle to the next. 

 

Since this article I've been fighting this..

 

Edited Wednesday at 10:48 PM by Mopar1973Man