Engine/Transmission (1998.5 - 2002) 98.5 hard starting?

[BDaugherty]

I've been bragging about the TDR to a guy at work. He's been having hard starts on his 98. 5 24V. It's got around 200K miles and it's on the 2nd VP44 and 3rd lift pump. I remember hearing about someone having similar problems and it may have had something to do with a check valve in the return side of the fuel system. I did a few searches and didn't come up with anything. Does anyone have any input on this matter? Referrels to a previous thread would be great.



Edit for clarity: It starts and runs fine, but it turns over for a long time before it starts. Low fuel psi light is in the works. Truck is bone stock and runs just as strong as ever.

Also, exactly where is the check valve?

 

[blacksheepdiesel]

Possible the check valve is bad. Don't have a thread for it though.

Is the engine turning over fast enough to start?

Any air leaks in fuel system?

Is the fuel filter known to be clean?

Is there a fuel psi gauge on the truck? If so, what pressure does it show before cranking? At idle? Accelerating? Crusing? WOT? If it is less than 5 psi and the filter is clean it is time for a new lift pump. What lift pump is on it now, stock or in the tank? May I suggest the AirDog. Mine has 300,000 miles on it with zero issues. Filters are less expensive than stock filters and last longer. PM me for dealer contact.

Godspeed,
Trent

 

[icman95]

I'll go with Trent. I had a hard starting on mine and it was an air leak in the fuel system. There are plenty of other ways for hard starting to occur, but air in the fuel lines will do it every time.

 

[blacksheepdiesel]

BDaugherty,

When his engine does finally start does it run rough for a bit and then smooth out? If so, almost 100% air leak.

Godspeed,
Trent

 

[BDaugherty]

The way that he described it to me was that it spins and spins, then starts and runs fine. To me it sounded like he's losing his prime... or the classic early 24V too much fuel psi hard start. He hasn't changed anything in a long time and the hard start has come recently. I just wanted some ideas as well as the location of the check valve since I haven't been able to look at it myself.

 

[icman95]

You mentioned that it sounds like he's losing his prime. That jogged my memory. I used to own a Freightliner with a 14 liter Cummins and even that beast fell prey to this problem. It would spin fine, but started really rough or only with starting fluid. It took the shop a while to figure it out, but some of the fuel lines were rotten enough to let a little air in and a little fuel out-losing the prime. Once it was started it ran fine as long as it wasn't turned off. The shop put on new fuel lines and all was back to normal.

 

[Kf6cmp]

Does he have the original factory lift pump?

 

[BDaugherty]

He's on his 3rd factory style lift pump.

 

[blacksheepdiesel]

Aren't the trucks that start hard mainly ones with FASS pumps? I didn't think the stock lift pumps did that.

I would look for a fuel leak. Some guys have found by parking uphill or downhill they experience hard starts one way but not the other. Search for a thread on that.

Godspeed,
Trent

 

[icman95]

One of those uphill, downhill problem guys is me. That's how I found my air leak in the fuel lines I refered to above.