Vacuum Problem
 

Hello, I'm not a diesel mechanic. This is my first Diesel. I've worked on many cars in my day but never a diesel. I'm sure I could find my way around it like I have so far with minor problems and maintenance.

I have a problem that started just over a week ago. Driving along I would punch the pedal some what and it would start spuddering like it was sucking air from a disconnected vacuum line. I've had this problem before on a couple of cars in the past. So its like riding a bike. You don't forget what it feels like. I know a bad fuel line can feel like it too. I've already checked that.

I did find two sections of vacuum line hose deteriorating and crumbling to the touch. So I replace them. But I still have the problem. I understand that the vacuum line on a diesel is nothing like on a gas engine, so I hear. I had the truck inspected today and the mechanic shop that does all our work on the cars said they couldn't work on the truck because of this reason.

So I am looking for someone to give me an idea where possible to look first. I have the layout of the vacuum lines for that year. I could easily trace them and see what I find but there is one thing that strikes me to think it might be some thing more specific as far as location.

When I am driving the truck a couple of things happen when it starts spuddering.
#1 it doesn't do it until the diesel is warmed up.
#2 It's okay cruising until I want to over take another vehicle or from the start of a green light.
#3 It is worst going up hill.

Any thoughts are welcome. Thank you in advance.

Welcome to DB.:hellox:

It sounds more like a fuel problem. Have you scan for codes? Have you changed the fuel filter? Do you still have the stock lift pump? Any other mods done to the truck? I hope it is not your VP44(injection pump). You need to take some fuel pressure reading at idle and at WOT.

Here is a lay out.

24 Valve Fuel System Components

You know I have thought about it possibly being fuel related. I just wanted to ignore it. I don't want it. lol

I haven't replaced the filter. I don't have a way to check codes unless I can rent the device from Auto Zone or other auto store.

Every thing on the truck is stock, straight from the factory.

Thanks for the layout. I don't know what that part is you hoped would not be it, but the sounds of it I don't either.

With being unemployed since 2007 I desperately need to try and fix this myself to save on the cost of labor. So what help I cant get here is seriously appreciated.

Oh! I did drain the fuel/water separator to check for water, but it was clean fuel.

check your lift pump pressure with a gauge.

Since I can't afford to go out and buy a gauge just to check the psi on the lift pump, thats out.

I read online that if I go out and bump the key. The lift pump should come on and I should hear it run for about a minute. Is that true? If so how loud should it be? Will be sound like a whining noise?

I tried it and all I hear are a couple of clicks from a couple of electronic parts.

maybe you can find somebody in your area that could check the pressure. if you dont have a lift pump running it will destroy your vp44.

well to help you out a little a diesel doesn't make it's own vacuum so a vac loss will not make a diesel run funny like a gaser does. You have a fuel issue and my guess is your lift pump is the cause and would not drive truck till it's fixed. as the injection pump costs a whole lot more. you can get by using a holley blue in place of the factory by bypassing it. but it's only a bandaid fix for now. best bet is save up what you can and get a raptor or a fass hpfp

I was sitting around thinking about the truck and it hit me. I remember I had one at one time and sure enough. It was in my other tool chest. So I have a Actron fuel/vacuum tester. I'll test it tomorrow. thanks

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No they don't have a vacuum system like gas engines. But there are vacuum lines or what ever you want to call them. Since I just replace a T and a short piece of rubber vacuum hose that was on a line that was sucking air when the Diesel was running at the time I replaced them. I placed my finger over the one end and it started sucking on my finger skin like a newborn on a tit. In fact I am looking at a layout of the vacuum line system of a 5.9 cummins diesel. A layout I copied off of mopar1973mans.com website. So if it doesn't have vacuum lines then I got a special Dodge Truck. What do you think?

Well if you read my post in what I told you it might make better sense to you instead of sounding like a jackass. I was just helping you out but if you don't want the help then don't post.

Oh I know Bud. right after I posted that I too thought it was wrong and inappropriate. Please accept my apology. I am having a bad time with some health issues right now. Taking 16 meds a day right now has got me up and down and doing the same with my moods. I'm hating every minute of it.

I posted that and saw I had misunderstood your post, treated you like an ass, but I had to leave the house to go to a church dinner meeting. So I had no time to correct it. As soon as I got home which was 5 minutes ago. I got back on my PC to tell you and apologize, but I see you we already offended. I am truly sorry for my commit. I mean that really. I came here for help, not to insult anyone. Doing so is not going to help me.
Thanks