2003 plugged in every night or no start, even when it's 20°c outside

[SRay]

I have a friend with a 2003 cummins that still refuses to start unless it's plugged in or ether is used. Even in the 20°c weather.



Hydro bills are soaring and truck has no codes. I know there are several temperature sensors on there but no idea where but one of them.



Truck has to be plugged in or we use ether which we don't want to use.



If we don't plug truck in, ether starts it right away. When plugged in, starts right away. Don't do either, the engine keeps on cranking until batteries are dead. Batteries are good.



If we cranked several times, then use ether, the engine fires up.



Stupid thing is, once truck fires up, even a few seconds of running, shut down, it fires right away again and will be good for the day. But over night after sitting for long hours, no, won't start.



Truck has almost 500,000 k or 312,000 miles.



Need ideas here. Thank you

 

[cerberusiam]

Good bet its injectors as thta is a classic symptom. Rail pressure needs to be soewhere around 3000 psi before the ECU will even fire the injectors. Cold the injectors bypass too much fuel, or, the cross over tubes are not sealing correctly. Warm it changes the dynamics of the rail pressure.



With those miles it could also be the CP-3. The FCA and COV will both contribute to a no start.



Run a injector return flow test to see where it is. You will need a scanner to check demanded versus actual rail pressure to verify but guessing it will be low on cold crank.



Might try re-torquing cross over tubes and see if and how long that will help.



I assum LP pressure has been checked, filters all changed? Thats the easy stuff to start with.

 

[SRay]

Cerberusiam: ok, I'm new in the common rail world as I'm used to p-pumps.

What is cov and fca?

The cross over tubes are the ones going from injector lines to injectors through the head?

Fuel filters have been changed 4 times during the winter as we assumed water in fuel as the truck always started in the shop when we changed them. Then we realized the truck started because shop is warm.

Have not checked lp pressure yet.

The scanner we have reads kpa for rail pressure and have no idea how to convert to psi.

Thanks

Shawn

 

[Dieselnerd]

Here you go! KPA to PSI converter



KPA to PSI Pressure Converter

 

[SRay]

I'll grab the scanner again.

 

[cerberusiam]

Cross over tubes are in the head behind where the line from the rail connects. You need to remove the rail line and get a socket on the nut or use a crows foot on then to TQ correctly. If they are not set correctly problems ensue, and, have found they will loosen over time. A little blue loctite helps keep that problem to a minimum.



FCA is the fuel control actuator, its what supplys fuel to the high pressure circuit in the CP-3. If it sticks or gets out of whack you get many different problems. Its the only piece on the back of the CP-3 with an electrical connection. The ECU sends a PWM signal to control fuel into high pressure side so they can be problematic.



COV is cascade overflow valve, it basically controls case pressure and routing of fuel to high pressure side, lube\cooling, and bypass. It is a spring loaded slide valve with ports on it. Spring gets weak over time it opens too soon and drops case pressure below the minimum needed and you get problems with rail pressure. Stock it should maintain 75 psi case pressure. No way to measure that unless a port is added to the CP-3 case.



The gear rotor pump can also be a source of problems. Fuel contamination will accelerate the wear on the gears and plates causing low supply flow. Lack of LP flow and pressure will cause cavitation in the pump resulting in the same problems.



With the miles that are on it hard to tell exactly where and how many places are contributing, could be several.