cougar

Yaknow, The more I think about this........ I think I'm going to fab a blank off plat for the fuel drain. I have seen o-rings seal under pressure and leak once the pressure was removed. And leak worse under vacuum. Considering the valve stem seal is sitting there kind of static, I can see that happening. Also, that same stem seal is were my leak was when the valve failed the first time, but under pressure.

KATOOM

So you have the ability to pressurize the system from the tank on? If so then you should be able to find the leak. If not then it may be one the return side.

cougar

There is about a foot and half length of hose between my tank and lift pump with an in-line filter. From the lift pump to the VP shows no pressure leaks, nor due the return lines while the lift pump is running. So, I'm going to isolate sections of the supply and return lines and pull a vacuum on them. If that section doesn't hold the vacuum, I'll know it is leaking.

KATOOM

Good call.

Dieselbuilder

Here is one for the books , When i was driving truck I had a Freightliner Cabover with a KTA 600 Cummins one day it was hard to start first thing came to me the way it sounded , there was a air leak it the fuel line. When checking over the lines there was no visible leaks i had to untie the bundle of air lines to get at the fuel line to inspect every inch of it then i came upon a twist in the line and when i opened it their was a 3/8 inch hole from ware and not a drop of fuel around it. Things will suck and not leak fuel!!

cougar

Almost didn't start this morning, even after letting it prime. Once it did start, it was fine. Something more than just drain back going on. Is there something bypassed while the starter is cranking?

KATOOM

These long threads are hard to keep track of so refresh my memory..... Did we explore the grid heater system potentially being a problem? Does it start better or more normal if you plug the truck in overnight? And lastly, I'm sure we did talk about this but I cant stress enough how battery condition and connection corrosion is HUGE on these trucks.

cougar

Grid heater was replaced along with the relays. That all works as advertised. Makes no difference plugged in or not, engine hot or cold. Batteries new last summer and are in great shape as tested. I checked as many connectors and grounds as I could get my greasy little paws on. It is also intermittent. It can sit for days and fire right off or a few minutes and hard start. Cranks to fire varies a lot also. And still no codes. Hard to do a lot of the testing correctly when your by myself.

KATOOM

OK..... This is the only thing I can think of which we didnt mention. I have "heard" but never confirmed that if the MAP sensor or the cam positioning sensor is faulty then it can cause hard starting. I never understood why the MAP sensor would cause this but I can see why the CPS would.

There doesnt have to be a code either as the sensor can be intermittently problematic or that the ECM isnt detecting the CPS for the first few seconds of cranking. Trouble with the '01-'02 trucks is the cam positioning sensor is located next to the VP and can be really difficult to access.

You may want to Google the topic just to confirm what I'm suggesting, but I think you'll be surprised how many threads there are on this very topic.

cougar

It has a new IAT because it was reading warmer than it was supposed to. Never heard of the MAP causing this kind of problem. And I agree, how especially during start up. Now I have heard about the CPS before. So I guess I'll hit it just cuz.

cougar

It's officially dead, won't start. Started a new thread "No Start".

KATOOM

Sorry to hear that. Well at this point you can jump the VP to see if you can get the truck to atleast idle, but if not you may just have to replace it. Make sure you get one from the right vendor too.

cougar

Jump the VP? never heard of that. Any instructions?
On vendors, I know to avoid those who are not Bosch authorized for the VP44, but how do you tell? I need cheap, but I also need reliable.
Also having trouble with cam position sensor part numbers. Mine is an 01.5.

DIESELWRKS

Cougar,
Sent you a PM

DIESELWRKS

2001.5 and newer have no crankshaft sensor, or engine position sensor. 2001.5 and 2002 use a camshaft position sensor.

Home Page good prices

#4921597 CUMMINS CAMSHAFT SENSOR.

this part is often listed as a part camshaft/crankshaft sensor for 98-2002.

but this part is only a camshaft sensor for the 2001-2002 years.
if that makes sense

the Camshaft Position Sensor references a tone ring and the signal is an input to the ECM. The ECM then sends a crankshaft (not camshaft) angle reference signal (derived from the camshaft position sensor) to the PCM on a dedicated line. The PCM and ECM communicate back and forth together via the CCD (Chrysler Collision Data) bus.