truck not running right

[RMcGuffey]

I need some help guys. My 1990 w250 isn't starting like it's supposed to. It's getting really hard to start, and takes it a few seconds to get it running up to speed. IT starts almost like it would in the winter, without any heat, real rough. But as soon as it gets going , it seems to run fine. I've started running a B2 soydiesel blend in it , but I can't remember if it was starting like this on regular #2. I've just changed the fuel filter, but it hasn't helped. About 2 1/2 years ago it got a new injection pump and lift pump. Anybody got any suggestions? The engine is stock. Thanks.

 

[BHiggins]

The first thing I would try is going back to #2 for a while... If the problem goes away then you've got bad fuel. (I'm from New York, I've never heard of "soy diesel" but it doesn't sound good... and I'm paying almost $3. 00 a gallon so I'm open to alternatives).

 

[cguthrie]

I would check all your fuel lines for leaks, sounds like an air leak somewhere, if not can't help checking.



Chris

 

[paccool]

Check the lift pump pressure. Could be a bad pump and the injection pump is having to pull fuel up from the tank. Just a thought.

 

[BushWakr - RIP]

Just by coinscidence we had a bio-diesel truck in the shop on Wed. He has similar problems.

We tested his lift pump pressure and it was pittiful..... near zero. We felt that the viscosity of the bio was too thick and the lift pump was 'not having any of it' so to speak.



Now this is only my personal opinion but I don't think this bio option is matured enough to be as stable a fuel option as the ole #2 is. There are definitely special steps to take when using it and I think that this fuel is not quite ready for masses...



If I were going to run it then I'd make sure that my #2 fuel tank had a good dose of cleaner in it as well as some cetane improver. That way when you switch to the #2 prior to shutdown you'll have some nice clean fuel with good cetane rating and cleaning properties in it. I think this would help "Purge or scour" the bio out of the line/pump/injectors prior to shut down,,,, this would also make startup easier too... at least that's my thinking on it...



pb...

 

[RMcGuffey]

Thanks for the help. I'm going to go back to #2 for a while maybe that will help. I wasn't sure if I'd have any issues or not with it. One drawback for soy is that it runs about . 25 cents more than #2. But when I checked the mileage, I think I gained almost 3 or 4 MPG. Not that bad of a trade off. I don't know why I'm having trouble when the city runs alot of their trucks on it. I did have a guy that I used to work with that had trouble with it also. I guess I'll run some cleaner though it and refill with #2. Hopefully that works. Thanks for the help.

 

[mudcat]

Pastor Bob I believe you have bio and vegetable oil confused. The bio you do not need to puge the lines before shut down, it is run in the regular tank.

I've been running b20, 20% bio from soybeans. I get this from our local co-op and it is pretty much right in line price wise with #2, I do get better mpg. They sell it as Premium with a cetane rating of 50. Much quieter, better lubrication (so they claim). The downside is that some trucks with the rubber fuel lines it will eat them up. This is probably what has happened to RMcGuffey's truck. It probably has a pin hole in the fuel line and is sucking air. No need to worry about it if you change them as the new materials used today is resistant the ill effects.

I've been using it for nearly 20,000 miles now with out any problems. I like using the bio for the quieter running. But the added benefit of helping the local farmers out and keeping from giving just a few cents to the rag head oil barons.

Just my perspective on bio diesel.

 

[BushWakr - RIP]

Hey 'Mud... good to know I was unaware of the distinction between the two fuels...



pb...

 

[phillips5]

I agree with the geting air fron someware. Probly beter check the lift also. Try pumping the lift pump by hand with the bleed screw loosend before starting and se if you get any air. Also one of my trucks was like that and it was the end plug in the ijpump between all the ijlines. I have the socket it is in ohio.

 

[RMcGuffey]

I figured I would let you guys know what I found. The metal supply line from the tank had rusted a hole in it. Of course the lines aren't available so we made one from brake line. We were able to reuse the return. Thanks for the replys.