darrenG

I just bought a '98 24v cummins & 5spd that came with a dodge a week ago and am wondering if the lp is dying. i'm not new to forums in general, just this one. I have been reading up a lot on the lp, vp44 (argh!) and trying to learn as much as I can about diesels. I have read other posts about the lp but can't find a conclusive answer. is it worth mentioning that this is my first diesel and i have no experience with them?

Here are symptoms:

Hard starts when cold - lotta cranks. if it's just been run it starts up normally. the longer it sits the longer it takes to start.
when it is cold if i hit the starter about 3 times and wait 5 seconds between hits it'll start up real fast. otherwise it's a lot of cranking.
white smoke comin' out at start up
under throttle, around 2800rpm it starts losing most of it's power
no clue what the repair record is except there's no rust on this truck and no dents. was owned by a boat dealership and is in great shape.

i don't have a fuel pressure gauge yet, or pyrometer, or boost, but am in the process of ordering them. what else should I check for to diagnose this? fuel pressure? Will the pressure at idle tell me anything?

I appreciate any help, newbies always do.


******edit********

I keep reading about CE and codes if the lp is goin' bad. I have no check engine light coming on.

1ST GEN.

I've never have a CE light with a bad lift pump, I would check the pressure it has but it sounds like it is to late for the injector pump

CTD NUT

I think 1st may be right. Not much of a way to check the lift pump without measuring the fuel pressure but your symptoms would seem to indicate a dying VP......Get the codes pulled - there will be some. Seems like most of the codes on these trucks will not set off the CE indicator so you can't go by that....

darrenG

what should i be looking for with fuel pressure? I'll need to check it under load?

Is there an alternative to using a vp44 again?

guess i'll start looking for deals on the vp44.

CTD NUT

The most important FP reading is at WOT.....an absolute minimum WOT fuel pressure reading should be 5 psi....you need to pull those codes!

Geico266

A low reading will give you an indication that that LP is bad, but the IP is most likly the cause of your starting problems. A bad LP will take out your IP because there is no "extra" fuel to cool and lubricate the IP. The "excess" fuel is returned to the tank.

If you use the search function you will have hours of reading and advice. I would not replace the LP with a stock one. I'd get a FASS II. Check it out.

The first guage to get is the FP. The others can wait.

Welcome to DTR.

darrenG

thanks for the welcome. can't wait to contribute.

the fp gauge is on it's way.

RAM2940

Its possible that you could have a air leak in the fuel system. This could make it hard to start, Then after its been running it could start normal.

White smoke at start. If its cold out you will get some white smoke for a minute until cylinders start to heat up to burn fuel. Heater grids kick in below 65 degrees.

Loosing power at 2800 rpm i believe your really above the power curve. Red line is 3200.

darrenG

Regarding the air-leak:

Yesterday (may 3rd), I was trying to find the fuel-water filter to see if it needs to be drained and was under the hood. Tracing the fuel line from the intake I saw a device - please excuse my lack of proper terminology, that at one end had a hose dropping down towards the axle about 8 inches long attached to a spout. There was a valve before the spout so I opened the valve to a woosh of air and an eventual flow of diesel. The truck hadn't been running for at least an hour but there was pressure, and obviously air in with diesel. Would that indicate air in the fuel line or is it normal?

Shovelhead

I've never had a "whoosh" of air, just a dribble of fuel when I opened the drain valve.
(Of course you DON"T want to try this with the engine running......... )

My L.P. is heading South also.
Started it tonight and saw 10 psi @ idle.
Shut it off, restarted and had 15 psi, then dropped to 10, then back to 15 and stayed there.

It's Pump number two and has been supplying 15 psi @ idle faithfully for the past 40,000 miles. (Pump Number one died at 37,000)

Found them online for ~$130.
The Dodge dealer wants $300+ for the exact same part.
Going to check a couple of local parts places tomorrow.

RAM2940

Well it sounds like you might have induced air into the fuel line. Air in the fuel line can make it hard to start or not start at all. If it was hard to start before you opened the WIF drain you still could have a small air leak somewhere in the fuel system.

Shovelhead

The rubber return lines have a reputation for developing small hairline cracks that don't leak fuel, but allow air to get into the system causing a loss of fuel prime which results in hard starts.

darrenG

Checked the codes and I got

Turbo boost exceeded
P1693 - DTC detected in PCM companion module
P0336 - CKP Sensor signal
P0232 - Fuel shutoff signal voltage too high

I cleared the codes and ran the truck for maybe a mile.

new codes were the DTC detected in PCM companion module and boost exceeded, nothing else popped up. In 4th or 5th gear, floored, it didnt want to climb past 70mph. like the turbo wasnt coming on at all, didn't hear it. complete lack of power.

i haven't checked the fuel pressure cus I can't find the schrader valve along the fuel line. I got the repair list from where I bought the truck and last year, less than 25k miles ago both the lp and vp44 were replaced.

CTD NUT

There is no schrader valve on your 98.5......there are two 1/8" pipe ports on top of your filter housing that you can tap a gauge into - one is pre filter the other is post filter.......

You will probably have to drive the truck much farther than a mile to ensure that you don't have any reoccuring codes...Your 0234 DTC is likely a sticky wastegate.....

Because of the complete lack of power and the 1693 DTC, I think you may need to go to the dealer and ensure that there are no other hidden codes lurking in the ECM that may help diagnose the power problem....

Shovelhead,

Where do you get a LP online for $130?!?!?! Please let me in on that secret!!

Shovelhead

you have mail