After I put my holley blue in and fixed a leaky connection where the fuel line connects up by the top of the tank, now my truck cranks like 6-8 times before it fires. I'm thinking it could be air in the line or maybe it's the additives I put in this tank. I added 6oz of gunk sulfer substitute and 8 oz of wallmart 2 stroke to 18 gal of fuel.

Today I cracked the inlet to the VP and bumped the starter twice until seemed to be coming out solid. But still the same thing.

I also put 5 gal of fresh diesel in the tank to dilute the additives. If I remember the hard starting happened soon after I put the fuel with the additives in.

Could I have messed injectors up with that mix? It was very little of each so it seems unlikely, but...

Oh, and I have two 1yr old 85 month Interstate batteries that tested with over 750 CCA a piece, but the truck cranks over slow. I can't recall if it's always cranked slow since I've had it (about a month) but it's always fired up on the second crank.

Any ideas what to start with?

 

How does it run after it starts? Is the lift pump mounted in the stock location?
What's the lift pump fuel pressure?
What year?

 

Sulphur Substitute?? You've got to be kidding me!! There's NOTHING BENEFICIAL ABOUT SULPHUR! Why on God's green earth would someone come up with a product to reinstate impurities in diesel fuel?? Moreover, why would someone buy said product?

OK, now on to your question: you are indeed getting air in the lines. There's a good chance your "fix" still leaves a leak in place that allows air into the lines. Somehow, your truck is losing prime when it sits.

Next question: does it fire instantly after it's already been run? In other words, is it only hard to start after it's been sitting awhile, or is it hard to start EVERY time, even it is shutoff and immediately restarted??

If, as I suspect, it's only hard to start after sitting awhile, then your losing prime because of a leak in the fuel plumbing.

If instead it's always hard to start, then you have another problem-- like a bad VP44.

Justin

 

Oh, sorry...

it's a 2001 and has had the intank pump put in. I bought a BD warning light kit and when I installed it never saw a blink out of the light. A few days later it started flickering so I bought a fuel pressure tester and sure enough it was about 5psi at idle.

So I bought a holley blue and mounted it on the frame right in front of the tank. Then I bought 14' of 3/8 fuel line and ran it from almost the top of the tank, to the holley, to the inlet of my fuel filter. Bled out the lines by bumping the starter and cracking the inlet to the VP. After that the truck started and had about 20psi at idle. That was a little too much I thought (Jumping from 5 to 20) so I clipped the spring and now am getting 16psi at idle.

 

I was under the impression that sulfer was the lubricating property in diesel fuel. Hence the US low sulfer diesel and the need for extra lubrication for our vp44 pumps.

It's hard to start every time. But it's interesting you bring up loosing prime because I have the bd warning light sensor at the inlet off the vp. When the pressure drops below 5psi it comes on. Before my added holley, with just the intank pump, when I turned the key to on position but didn't start it the light would come on briefly then shut off. Telling me there was at least 5psi in the system. No matter how long I sat without starting the light would stay off. (telling me it's holding pressure)

Now I do the same and the light goes off but comes back on only after a couple of seconds. There's pressure being lost somewhere. But there are no leaks anywhere. Could this be the problem?

I checked the codes and there's nothing about the vp being bad (the injection pump timing code)

 

Found the problem. It's the holley.

Hooked up the fuel pressure tester at the banjo at the inlet of the fuel filter. With the holley working inline with the intank pump and bumping the starter it went up to 16 psi. as soon as the holley shut off it dropped to 0psi.

Now this can, and possibly is, due to the fact that I shortened the spring in the holley to reduce fuel pressure. I think the spring is not providing enough pressure on the plunger to hold fuel pressure. So it's leaking back into the tank.

I bypassed the holley, bled out the lines and it instantly fired up. Back to normal, and fuel pressure builds up and holds when I turn the key on but don't start it. But fuel pressure is at about 7-8psi with the intank alone.

So don't shorten the spring of the holley. I've heard of people stretching it for more pressue so I thought I'd shorten it for less. I think I've even read of people doing that. Not the case. When you shorten it I guess the plunger doesn't have enough spring pressure to maintain the fuel pressure it built.

So the hollety loosing pressure was my problem.

I went down and bought a holley red with 7psi and put that in place of the blue. Bled out all the lines and after the initial fire up, fires right up after 2 cranks like normal. Fuel pressure sits right at 13psi.

I'm done.

 

Hey awsome! I had similar problems last winter. Fuel psi was to high from my FASS 150 (21psi). Dan from DPP sent me a lower psi regulator spring. Helped alot, now 15 at idle. Still had hard restarts time to time. Here's a little extre thing I found out if you live in a cold part of the world and use #1 or winter blend diesel. Dodge has a TSB for hard starts when the engine is or at normal op temp. It changes the run time of the lift pump from @30sec to like 3. Must have been over primed before? Heres a link to the TSB.

http://dodgeram.info/tsb/2000/18-15-00.htm

I had the dealer do the reflash with that TSB and the High Idle warmup TSB. Starts like a champ every time now.
The high idle warm-up is great. With my exaust brake on and the high idle warm-up kicked in I'm down the road in about 5mins after a stone cold start-up at 15ºF engine temp to 160ºF. I don't even plug it in unless it's below 10º or above 30º. Way faster warm-up time.

 

Sulphur is not a lubricant.

But the process that refiners use to remove sulphur from the fuel also has the side effect of reducing the lubricity of the fuel. So it's the PROCESS of removing sulphur that reduces lubricity-- not the absence of the sulphur itself.

Aside from the reduction in lubricity, ULSD is only a good thing-- there are no other drawbacks.

 

Not to argue, but why is sulfur added to heavy duty cutting oils if it is not a lubricant?

 

There are other reasons to add things to oil other than increasing lubricity. Motor oils have all kinds of additives that have nothing to do with enhancing the lubricity of oil. Some are there to affect the chemistry (pH), some the thermal conductivities (ability to carry heat away), and so on.

I can see the micro-abrasive properties of sulphur having a beneficial polishing effect on a cutting blade when used as a lubricant additive, extending cutting tool life and so on.

I'd also suspect that sulphur may have some EP lubricating qualities when used with an extreme-pressure cutting lube.

You tell me-- why is sulphur added if it's not a lubricant?

JH

 

Maybe it helps bind some of the components together like it does latex to make rubber.

 

OK.

So maybe sulpher being a lubricating property in diesel is a common misconception. Maybe so wide a misconception that the marketing people at Gunk take advantage of that and market a product called "Sulpher Substitute" that replaces the lubrication absent in todays USLS diesel. Even though it has nothing to do with the absence of sulpher, it still enhances the lubricating properties of diesel fuel.

I'm sure they wouldn't make a product that introduces completely non beneficial additives to fuel. Rather, they take advantage of a buzz word and are still adding the necessary benefits in the form of lubrication that the process of removing the sulpher has taken away.

Make sense?