Hard Cold Starting

[Josh]

Well I've ran out of ideas, short of replacing the HH. Ive check all the fuel lines, intank pump, replaced my filters again today, yet when she is cold she doesn't want to start.

Its slowly been getting worst and worst, and when I try to start it, I have to keep the pedal to the floor, and she will crank 20-30 seconds before it will go into a rought low idle(with it still floored), and then after idling roughly for 10-20 seconds, she will rev up like normal, but if I let it down to idle with out keepering her at 1000+rpm for 10-20 seconds, she will stall out and die. Ether appears to make no differance at all. This happens from 40-65 degress out side.

Letting it sit overnight is the worst, But if I let it sit for 4-5 hours after getting to operating temps, she fires up with in 3-5 seconds.


So I just figure I should see what yall feel the next logical step to take is.


Btw, it does this on strait diesel, gas, or a mix of all + WMO


Thanks

 

[velociT]

Wow. Wish I could be of assistance.

Hope you get it figured out quick...

 

[wsucougarx]

Hmm, wonder how your IP is

 

[rosco]

Is you "in tank" lift pump workiing? If you crack the bleeders on the secondaries and turn the ignition switch ON, do you get fuel out the bleeder? Its not enough, if you can hear it running, but you have to have fuel run out the bleeders. (It can run, but not pump). When you shut it down, fuel will bleed back, out of the filters, to the tank. That sounds like that is what is going on. Seems like there is a booster pump in the IP, that will run it, once you get it going, but that is the hard part. It doesn't like to do the initial "pickup". Make sure you have pressure fuel to the secondary filters. You also should be able to put a pressure guage at the tank outlet, and check for pressure. Something like +10 psi to 15 psi, would be great. Anyway, this is you first step in trouble shooting.

 

[Josh]

Yes i have lots of fuel comming out of the bleeder screw on top of the secondarys, with the intank pump on.

 

[Earth]

It's possible that low compression is the problem. How is the power when she's going down the road? A solution to hard starting in the colder conditions is to live with it if the truck performs well after its' going. A little shot of ether or some quality time with a block heater will do the trick. You might also consider checking the fuel lines under pressure to find hidden leaks. Good luck. Been there.

 

[Farmun]

Check for air in the fuel return lines that connect the injectors. Mine started developing leaky return lines, that would let the fuel drain back down hill after sitting several hours. The results were very similar to yours - hard starting and rough idling, until all the air was flushed out. I could actually see this happening, as the fuel return lines on mine are somewhat clear, and I could see the fuel in them, or the lack thereof. When all the bubbles were gone, it was runing fine. And yes, this issue seemed to be more of a problem in colder weather. Just my experience, and something to look at.

 

[kurtkds]

Check for air in the fuel return lines that connect the injectors. Mine started developing leaky return lines, that would let the fuel drain back down hill after sitting several hours. The results were very similar to yours - hard starting and rough idling, until all the air was flushed out. I could actually see this happening, as the fuel return lines on mine are somewhat clear, and I could see the fuel in them, or the lack thereof. When all the bubbles were gone, it was runing fine. And yes, this issue seemed to be more of a problem in colder weather. Just my experience, and something to look at.

Ditto...

Josh, try running your intank pump for about 30 seconds before you try to start, that will help flush out the air. I had the same thing happen to me, bad fuel return lines.

 

[hdexpert]

Josh have you done a compression test yet? Sounds like a low compression issue to me. Good luck!!

 

[hklvette]

Josh have you done a compression test yet? Sounds like a low compression issue to me. Good luck!!

what compression tester tool do you use? I'm actually looking to get one for diesels and would like one that has the right fitting for the LDT.

 

[Josh]

Well, Ill see about getting a compression test done in the next few days... We will see how that turns out.

 

[Josh]

Well I just got back from my second mechanic I trust, and both said I have a fuel issue. So Im axing getting a compression test right now, and am just going to replace all the fuel lines from the tank to the IP. Im guessing there arnt pre-bent lines so looks like I need to go out and get a tube bender and go to town.