Hey everyone,


I have a 1997 2500 diesel, 4 by, 5 speed.

It's hard to start and keep running. I have had it to the dealer who apparantly tested manifold heaters and replaced relays ( over $500.00) Brought it home and nothing was better. Took it in again and they diagnosed ( apparantly) a bad lift pump using clear fuel lines. They said it was pulling air in and said it now started "excellent". So I brought it home after paying $ 900.00 for that. Left it out over night @ -18celcius not plugged in. I got it started after a couple of trys and it ran fine for 20 minutes idling. Left it for a couple of hours and tried to start again but I couldn't get it going no matter what I did.

I just can't afford to have the throw parts and labour at a problem they obviously can't figure out.

any ideas out there would really help.

I am thinking about a new fuel heater rebuild. Should I put a new heater, gaskets in or buy the whole assembly?

Thanks everyone

Thanks everyone.

 

I have a 97 5 speed, sounds like it's the same problem. What kind of timing, pump mods, etc does it have? Any leaks in the fuel system? I'm in the process of checking mine over, and have come up with working lift pump, working grid heaters, so forth and so on. I've been told that the 15* timing I have shouldn't start hard at 10*F.

 

No Mods whatsoever on mine.

280kms. Brand new lift pump new manifold heater relays.

Next step is to rebuild or replace fuel heater assembly. Check all fuel lines to and from.

IF that doesn't do it I am stumped .

I am sure between the two of us we can work through our problems.

 

What's it do when you try to start it just crank and crank?? Did this just start with the cold weather?? Are you giving some throttle when you crank it?? What is the idle set at when warm??

 

i had the same sorta problem went to cummins and got a new lift pump fuel heater mine had a melt down and a grid heater and relays did the lift pump and heater at the same time and seems that hose that went from the lift pump to the heater was were i got an air leak and now runs like a champ just went out and started it around 0F and fired right up no smoke never did do the grid heater

 

They should warranty there work for one , make sure you get all your old parts so that you can double check there work .
Drain some fuel from the filter into a glass jar to check for issues .
Pressurize the fuel tank with about 3 lbs of air pressure to look for leaking lines / hoses , from the pump to the lift pump is a vacuum so you may not notice a leak with out pressure .
Get a fuel pressure gauge connected & check for fuel pressure , should be about 26-28 idle , 34-36 high rpm lbs , if not , pinch return line slowly , if it comes up may be overflow valve , also may be lift pump .
But what ever , it should be tested before parts go in , if parts do not fix it then there should be no charge .

 

We need a little more info on how the hard starting is. Does it start well if it has been run recently? Does it make a difference if you are parked nose uphill or downhill? I suspect that you have an air leak in your fuel system but it is hard to say without more info.

To check the grid heaters, watch the voltmeter. When the wait to start light is on, the voltage should be down around 8 or 9 volts and then it should pop up to 12 or so when the wait to start light goes off. If it doesn't get sucked down with the WTS light, they aren't working.

As far as air leaks go, there are several possible sources. If your fuel lines are original to the truck, they are in need of replacement even if they are not the source of the problem. The rubber cracks and starts leaking air but the cracks are so small you can't find them. The best way to replace them is to put in marine grade rubber lines all the way from the tank to the engine(both send and return). The other probable source is your fuel heater. The plug tends to melt out on it and cause an air leak. Try unplugging it and seeing whether there is diesel on the plug. Also, as a very temporary fix, some people have had luck with jamming the connector full of really heavy grease.

Good luck. These problems can be real frustrating but you will get to the bottom of it.

 

It's possible the shut off solenoid on the pump is not moving full travel.

 

Good advice above. I would start my search by looking at the electrical connector at the fuel heater element. Unplug it and look for fuel. I wouldn't consider its lack of operation as a possible culprit for starting, just an air leak.

Next I would inspect the rubber fuel hoses that lead from the rear of the engine, over the bell housing, especially the return hose which is known to deteriorate and cause leaks. The next place I would go is the overflow valve, which can get weak and cause low pressure and a loss of fuel system priime.

 

I was going to start by saying the dealership is stupid, and doesn't know what they're doing with a diesel. But since you already spent 1400 for them to throw parts at it and it doesn't fix it, then they better start standing behind their work and fix the actual problem or give you your money back so you can go elsewhere.

On a 10 yr old truck there are so many places to look. Neither of my trucks has intake heaters or fuel heaters, and the coldest they're fired off where I live is 10 degrees. But it sounds like it's colder where you live.

Fuel heaters melt at the electrical plug and let air in when parked, so you can't rebuild them you simply replace them. Lift pumps get weak, or leak and let air in. overflow valves get weak, and I've seen some stick open. The rubber fuel supply and return lines crack, and let air in when parked, or will rupture. Then onto the fuel shut down solenoid, the relays are a common weak point, and you can easily replace those yourself. When you're cranking, make sure the shut down solenoid is lifting up all the way. And make sure your idle adjustment is around 800-850 rpm.

 

check the fuel shut off silenoid

 

If your fuel pre-heater and wiring harness are gone, you can buy the parts at a Cummins dealer. Dodge sells the complete heater only and for about double the price.

It really sounds like an air sucking problem. Try giving the priming bulb on the lift pump a few pumps and see if that helps.

BTW, the electrical pins on the pre-heater tend to suck air once you unplug the harness. When it happened to me, I left it unplugged and wrapped the pre-heater with electrical tape while waiting for parts. It worked good.

Good luck with it.

 

OK Guys,

First off thanks for everything. I was away for a day there.

I will try all your ideas tomorrow. MY buddy has a hoist and I will put it up and start looking for air leaks both before and after the lift pump.

I will work systemmatically on all your ideas and hopefully it will work.

I don't expect the dealer to starnd behind their work but I have a call into them and I am sure they will call back on MOnday.

Dartmouth: Once it is totally warmed up and run around for awhile it seems that it will start up fine. That being said I managed to start it the other morning ( after new pump and heaters) let it run for twenty minutes and then left it for 2 hours and then it wouldn't start now matter how much throttle I gave it.
I think the heaters are working as I can see the voltage drops on my dash voltmeter and I can also see when the stop.

So black marine grade fuel line is the one to use eh? Do you know the sizes offhand so I can get some before I put it on the hoist?

I will work on it tomorrow and keep everyone posted as to the outcome.

Again, thanks everyone.

 

Look for leaks in the return line as well. If I remember correctly, the supply is 3/8" and the return is 5/16". Hopefully someone with a better memory will confirm this.

 

That is true. It's usually only the return that gives trouble, and it's just under 2 feet you need (I think.) I usually get some quality fuel hose clamps with rolled edges so they don't cut into the hose.