I have a 99 Ram 3500 with the cummins 24v. I use the truck for towing my 4 horse trailer, and it does the job excellent. I recently have had a built auto trans put in when the old one took a ****. But overall it's been very reliable and a good truck, I've had it for about a year and a half now.

Recently it's been getting a little harder and harder to start over the last month. But the issue seemed to really start when I hauled a full load of heavy horses up the steepest hill ever (I had to put the truck in 4wd or the dualls would just spin!) Then last week it would just not start. But you wait awhile then it will. It will nearly always start cold in the morning. And it will always start when hot. But after shutting it down, once a few mins has passed, it won't start at all for a few hours. It stranded me this week, and when I got it towed home, it fired right up! So frustrating!

First the mechanic replaced the battery's, didn't help much, espically for $400! Now over the last 2 days he said and replaced the intake grid heater. I new it couldn't be the heater itself as the issue, he claimed it was causing a malfunction to other fuses or something. But it had trouble starting at the ranch today. He also says he checked the fuel pump system. I do hear it humming when I shut it down.

It runs excellent when it's running. No issues driving or hauling. And it has nothing to do with ambient outside temp. Any ideas?

 

Also doing some reading, I heard if there's smoke coming out when attempting to start, it should be getting fuel? I did notice some white smoke vapor coming out for a little while after attempting to start it e other day. Hoping it's not an expensive vp 44 or something.

Would trying some starting fluid be a bad idea when it doesn't start? I don't want to blow anything up, I blew up a valve on a motorcycle years back with it

 

Have you pulled any codes?

do a search on here title hard starting while warm or hot.

also from Blue chip diesel's website for VP 44 diagnosis

HARD START WARM OR HOT,
LONG CRANK TIMES

We have learned this past summer that long crank times when warm or hot are not always caused by a worn-out distributor on the injection pump. Before you replace the injection pump for this symptom be sure that the starter cranking speed is adequate. This is important as it is a mechanical pump in the injection pump that makes more pressure and flow the faster it turns, and when the pressure created during cranking is not enough to pop off at least three injectors, the engine will not start. So there may be as many as two causes for this symptom. One, is that it's not cranking fast enough to make enough pressure, the other is the pressure is being lost in a worn-out distributor that is expanded due to heat soak, OR BOTH. Before buying a pump we suggest that you first check electrical parameters for the starting system. A good starter at operating temperature can draw from 450-700 amps, and the battery voltage should never go below 10 volts during cranking. If your starter draws more than these specs, or the battery voltage goes below 10 volts when cranking, you need to fix the starting system, FIRST.

When you have determined that the electrical system is up to snuff, then you can try our clever trick of running cold water from the garden hose over the injection pump when it's hot, for a few minutes, and if that makes it start right away, then you know cranking pressure is the issue, because you shrunk the metal in the distributor and it fits tighter to the rotor and makes more pressure. This indicates a worn out distributor, and a replacement VP44 is needed. If you have just replaced the injection pump and the problem did not go away, then most likely you have a slow crank problem. If you didn't have the problem before the pump swap, then most likely it is a pump issue, BUT,,,,the sad truth here is that a replacement pump may have a worn-out distributor just like the previous pump did. No one wants to put a new distributor on every pump, as it is SO EXPENSIVE. As of this moment in the industry, there is no good test available to the rebuilder to accurately determine if a distributor will perform correctly in hot conditions. The best any rebuilder can do is check pressure and fuel volume from the VP44 at cranking speed on the test stand and if it passes Bosch specs, then it has to be presumed good. This test is performed in a 70° air-conditioned pump room and in the real world pumps are subjected to the latent heat transfer from a 195° engine! The bottom line is you REALLY have to test the starter and batteries first to make an accurate diagnosis for this frustrating symptom.

Another cause of this issue that we have run into recently, is a delay getting 12 volts to the primary side of the fuel system relay. This shows up as a delayed battery voltage on pin seven (red wire with a green tracer on Dodges) in the plug going into the VP44. First test for the delay by removing the big plug on the injection pump and verifying the time it takes to get battery voltage on pin 7 of the plug or on the red wire with a green tracer. To accomplish this, pull the locking slide in the plug toward the fender. There are two half round indents on the slide lock and you will need to pull pretty hard toward the fender while wiggling the main plug with the other hand pulling toward the firewall. When you have the plug in your hand, hold it so it looks like a smiley face, with six pins below the smile and three pins above. Use a test light or voltmeter to verify how soon you see battery voltage on the bottom right pin (Pin 7) after putting the ignition switch in both the “run” and “start” key functions. When you reinstall plug and push in the slide lock, push the plug toward the pump and you will see that when the lock moves in, it pulls the plug in towards the pump. When you think it is on correctly try to remove the plug by pulling on it. If it comes off you didn’t get plug on far enough before you slid the locking slide in. This test tells you when the injection pump is getting electrical power from the fuel system relay in the PDC (Fuse-box under the hood). The ECM not only turns on this relay but this relay also powers another part of the ECM that turns on the lift pump too. The electric lift pump is powered directly from the ECM, not the relay, to control WHEN it comes on. An audible indicator of this delayed voltage or start problem is when you don't hear the electric lift pump come on for 4 seconds when the key is first turned on and for 25 seconds when it is turned to the start function. The relay enable power goes through two connectors, #125 and #130 between the ECM and the relay. The delay problem can be caused by a delayed signal on the brown wire with a white tracer at the ECM connector, indicating a bad ECM, OR a loose connector #125 on the firewall. We have not heard of #130 being a problem yet! Working on these old trucks nowadays is getting pretty interesting, eh?

 

Thanks for the reply and info. No there aren't any codes right now. I did some reading on here and from blue chip, and it sounds like it makes sence about the vp44. What I'm thinking is like they said when I let it sit off for a few min hot then it heats the computer in the vp44, causing it to not work until all cools down, and said to try pouring water over it for a couple mins when it won't start and see if it helps

 

1. Get a new mechanic, he's just throwing parts at it at your expense...

2. DO NOT USE STARTING FLUID. The Cummins uses a grid heater which resembles the inside of a toaster. Starting fluid will blow your intake off. This is also highlighted in your owners manual.

3. What Dieselwrks says.

 

You got at right! Well this mechanic also tried convince me a new half ton truck is better, and can tow the same! I asked him if they can pull 30,000 lbs gooseneck loaded down like mine has, he said yea no problem! Can't imagine a half ton truck trying to pull that kind of weight.

They aren't certified diesel mechanics, but I've had good luck with them in the past with my gas truck, I think they really just don't know their stuff with diesels

And thanks for the warning! It seemed to Ricsky, but I remembered a friend with an old ford diesel that had the same issue and used starter fluid, but yea that doesn't sound good!

 

not sure what shop you are going to but. I have alot of family close to where you live. I asked them if they have ever used a shop . They said they have used

Lee's Diesel service
6484 Chestnut St, Gilroy, CA ‎
(408) 848-8280

I do recommend that you may look at other shops. Talk with them on the phone. write down everything on paper sorta like a time line of what has happend. symptoms etc. A person that is a true Diesel mechanic does just that. Not a all around garage mechanic. a Certified diesel mech will know all well the 6 bangin cummins in all the applications.


also there are some well know diesel performance shops in your area too. Those for the most will have certified diesel mech's too. well the good ones that are out there.

 

I'm hoping its not your vp but it is starting to sound like it....

Starting fluid is ok on older diesels with glow plugs, just not the Cuminnsssssss's

 

this might sound like something off the wall..

but what is your 'wait-to-start' light doing? acting normal or blinking?
if its blinking...try the stuff on bluechips site..
I did..I was having simular starting problems..my wait-to -start was blinking
turned out the ECM was dying..yep $800 later..starts fine..diagnose then spend the money..

-dkenny

 

^^Not bad advice, when I thought I cooked my vp it ended up being the ecm....threw a bunch of codes though.

 

yea I'll definitely have to check out a new shop. I just wish these guys didn't claim to be diesel mechanics but I found out none are certified

 

The wait to start light is normal, I just notice the airbag light comes on and stays on after a few seconds of cranking when it won't start.

Yea unfortunately I bet it is the vp, I noticed it said remand factored so it is not on it's first one.

It's just so frustrating, **** truck already cost $3,000 trans, needed major front end works etc. I new the vp and trans would go when I bought it, but why does it all have to happen at once! Oh well

 

Man, I feel ya......

At the rate I have been replacing parts on my 97 Tahoe, it's gonna be brand new again in two years!!

 

Exactly! So I called this diesel shop in San Jose I believe called fjm, they said if it turns out vp 44 they will do it but need a $2200 transfer pump? Is this bs? I mean that'll put me out $3500 I can't do that right now. They are supposbly cummins authorized

 

It is killer because I'm only 18 and I have horses to pay for, this truck is worse than vet bills!

Also I got a code I think it was p1690 or something, when I researched it I think it means mid communication with vp44 and ECM