Archived Truck still broke

[Rattler]

O. K. , after being towed home at 2 a. m. sunday morning because the truck refused to start, i replaced the lift pump and filter and it is not a lot better. I bleed everything sunday morning and got the truck to start, but it required a lot of cranking when you shut it off. So i replaced the above items and still the same even after a 25 mile round trip. Also the idle is a little erratic. So please tell me what to look for next!

 

[Pit Bull]

How is it smoking? Is it different than normal? Black? White? Blue?

 

[Rattler]

Once i get the truck running down the road it seems normal, same smoke when i get on it, and no loss of power. It just won't start very well.

 

[A Johnson]

If you have a manual fuel pressure gauge hook it up and monitor cranking fuel pressure. It should be below 5 psi while cranking. If you have a ball valve that you can put in place of the fuel pressure gauge hook it up and bump the starter to make the lift pump run , put the valve in a bucket and check for air bubbles in the fuel, when you get a little fuel in the bucket put the valve under the fuel this will help you see the bubbles. bump the starter 2-3 times to make sure any air you are seeing is not from the line you just put on. If you find air then of course you need to trace it down and fix it.

If there is no air then then try starting it with the lift pump unplugged. If it then starts I would suspect the vane pump inside the VP-44 is marginal and not building enough pressure at crank speed to over come lift pump pressure which may be holding the shoes off of the internal cam ring in the high pressure pump.



Another thing I have done several times but I will take no responsibility for damages if you do it, is as follows:

Disconnect grid heaters and remove charge air cooler tube at intake manifold. Give it a little squirt of starting fluid while cranking. If it starts right up and runs normal then once again I would suspect the same thing that I mentioned above. (vane pump inside vp-44 can't build pressure at normal cranking speed) Make sure you have no source of ignition that may ignite the starting fluid.



Hopefully you will just find something simple like air in the fuel.



A Johnson

 

[Jetson]

It sounds like you may have a deteriorated rubber hose on the fuel return line. It runs from the back of the head down to the frame. The line can develop small cracks, causing it to loose prime. Try to find the line and check for seepage.

 

[Rattler]

Well, i have checked everything i can find to check, bled everything else, and i still have a hot start problem. It starts pretty good cold, but hot you have to crank the sh** out of it to start. Tomorrow i am going to take it to a guy who can check for codes and maybe get me fixed.

 

[DEZLPWR]

I hope I'm wrong, but....

It sounds like your VP44 may be going t/u on you... I remember reading TDR posts in the past where guys had similar symptoms and it turned out to be the VP44. Sometimes the injection pumps do wierd stuff (ie: hot hard starting etc. )before they crap out, and and sometimes they just completely go t/u without any warning whatsoever... .

I hope for your sake it's not the VP44 and it is something else! Good luck.

 

[Bigramguy]

Wasn't there a TSB for the hot starting problem? Something about cutting back the lift pump cycle time to help hot starting. May be one more thing to check into if all else fails.

 

[Rattler]

The truck is starting better now, although i don't know why. I have not had it scanned yet. The guy i am going to have look at it can't get to it until wednsday of next week. I will post news as soon as i find something.

 

[Rattler]

Well i finally had the truck scanned today and still don't know alot. There was a code for "pump timing" but it cleared itself after being scanned. The truck has been starting good for the last week so i guess i will just drive it and see what happens.

 

[jaughenbaugh]

Hey, I have the same problem with my 98. 5 3500. First it starts hard when hot not cold i. e. sit for two hours and wont start, sits for 2 minutes starts fine, sits for 4+ hours and it starts fine. The first thing I did was install a lift pump. This kind of helped. Then I read a TSB on it and it said the computer had to be re-flashed. This fixed the problem for a couple of months and now it is doing it again. The cummins dealer tells me the injection pump is bad now. I don't know if I believe them though because I read a similar article that someone Replaced th inj pump and had no luck and then replaced the $37 crank sensor and fixed the problem. If it is the computer needing to be reflashed it is about $150 at the cummins dealer and I don't know about at the chrysler dealer since mine doesn't work on diesels.