Hi All,

I recently had issues with the fuel lift pump in my truck going out. Replaced that and the fuel filter and the truck is hard to start. I turn the key , hear the lift electric pump run for a 10 seconds or so, let the glow plug light go out, and roll the key. Its taking 3 or 4 turns of rolling the key over to get the truck to start up. Once its running it purrs great. Plenty of power at high way speeds, idling fine. The batteries seem ok, its still rolling the engine pretty well, on the 4 roll of the key when it finally kicks off. What could be causing it hard to start? This problem is still noticeable when the truck is warmed up. Meaning I pull into a store, come out after just a few minutes and it still takes two rolls of the key to fire it up ?
any thoughts on what to check would be helpful.

thank you,
Jon

 

I just saw this thread..

sorry its so late, but I think I can help you.... You might wanna consider an injector issue is your culprit.. You may have worn out components or check valves in your common rail injectors. overnight they may be "leaking down" and allowing too much fuel to return to the tank... You may have one or more than are further gone than good now if its getting worse...

a few questions to consider..

One.. how many miles on your truck?
two.. original injectors if over 100K miles?
three.. do you run your tank to 1/4 or less more often than not?
four.. do you have two micron filtration?
five.. any DTC's?
six...any smoke out of tailpipe? injector tick or knocking?
seven.. have you checked your fuel filter to see if its plugged up?

injectors over 100K miles, if you have no two micron filtration, they may be on their way out.. Honestly these things are the Achilles heel of the CR cummins.. 28000 psi going through those tips? think of 6 little plasma cutters goin on into your piston chamber... and it wouldn't be a bad thing to bench test them, or have a flow return test done on them...

thanks and sorry for late reply

 

Hi there,
One.. how many miles on your truck? 207,000 miles on the truck. (I bought this truck new, it had 3 miles on it from the factory)
two.. original injectors if over 100K miles? Yes orginial Injectors, No engine work has been done to this truck.
three.. do you run your tank to 1/4 or less more often than not? Yes i run the tank down every week. I fill up when the tank is empty.
four.. do you have two micron filtration? No - Honestly i dont even know what this is. im guessing an add on fuel filter. so no, i just have the factory fuel filter in the canister. and i replace it every 50,000 miles. it was replaced last month same time i replaced the lift pump.
five.. any DTC's? No i have no modifications to the truck.
six...any smoke out of tailpipe? Ill double check the exhaust today. But i have not noticed any unusual amount of smoke from the tail pipe.
injector tick or knocking? No i have not noticed any ticking or knocking.
seven.. have you checked your fuel filter to see if its plugged up?
New fuel filter was installed last month. and the old one that came out looked fine.

Some additional things ive noticed. when its cold, this truck does not want to start. If i plug in the 110Volt power to the block heater, it fire s right up and starts quick. If i drive it, stop at a store, run in for 10 minutes, come out and roll the key over, it still takes 8 seconds for it to fire up.
How do you test for injector issues ? or Common rail check valves ? thanks for any help...
Jon

 

First, congrats on keeping everything stock. That is so hard to do...

The "micron" rating (in simplest terms) refers to the smallest size of the particles that the filter will trap. Stock filters are 7 micron, some baldwins go down to 5. Unfortunately, Bosch, the injector manufacturer, calls for 2 micron for best injector service life.

50k miles between filter changes is too long.

The problem you describe is a classic excessive leak down situation as TxDiesel alluded to.

The injectors at 200k are tired and need to be rebuilt or replaced.

What happens is after you shut down, the fuel in the injector "leaks down" or returns to the tank because it won't seal well enough to hold the pressure. The longer the truck sits, the more fuel leaks back and the longer it takes to start. So, when you go to start, the pump has to first replace the lost fuel (fill it up again, so to speak) then build enough pressure to fire the injector. The fuel system requires 3000 psi before the ECM will fire off the injector and start the truck.

While what I described is the most likely cause, it may not be the only cause.

You should have the injectors pulled, do a bench test on them and go from there.

 

Hi all i wanted to post back whats happened to date. Last week when the cold front blew in my truck would not start. I was able to get it going using Ether. The next day i took it in to an injector mechanic. He felt one injector needed replacing cause the step down from 2000 rpms was smooth. So he kept the truck a few days and narrowed down the not starting issue to one cylinder.
He capped off the fuel rail to each cylinder one at a time until the truck started. Bank 4 was the problem.
So two days in a row in freezing weather the truck has started.
New Bosche Injectors are expensive!!!

thanks for the help,
Jon

 

I am glad you found the problem. Be aware that the rest of the injectors are inclined to follow at some point and be prepared for the replacement costs.

 

So how long do these injectors last ? is there any thing I can do to prolong their life, like add some thing to the fuel ?
I paid 365 for one new injector, is there a better price some place else or rebuild them ?
thanks again Jon