K_88Trooper,

Thanks for the support. Unfortunately I've already removed that filter (part of the fuel system modification work I performed a while ago) so that's not the cause.

I re-connected the vaccum cannister to the vac pump and pulled a vaccum on the fuel feed line - it seemed to free whatever was clogging the line and the flow now seems good.

Now, however, the fuel I get out smells awful, like the old varnished gasoline I drained out. I did rinse the tank w/ some kerosene before putting everything back together, but it still really smells. I added about 5 gallons of diesel after reassembly, too, so the actual amount of old gas is likely very small. I hope it hasn't done any damage to the injection pump in the short time I've been running it.

I may pull the tank, either clean or replace it, and then run new fuel lines along the driver's side of the truck to be certain there won't be any interference between them and the (future) exhaust system.

Did I mention the charging system in inoperable? I also blew the power steering pressure hose up today. Not a good day in the garage - had to get out of there after 2 hours and lift weights to blow off some steam!

Well, I need some advice guys:

I drained and pulled the gas tank, fuel filter/primer pump assembly and all rubber lines out of the Trooper. I haven't checked inside the tank to see what's what yet, but the fuel coming out of it was ugly. Reddish in color and it smelled like bad gas, although it still had the consistency of diesel fuel (and was definitely mostly diesel, as I rinsed it with kerosene and added about 3-4 gallons of diesel before running the engine initially).

So, I replaced the primer pump with another I bought (works great, remember to open the bleed valve first and it draws fuel like crazy), reinstalled the old filter, got a fresh can of diesel and ran both the feed and return hoses into the can. I re-used the clear plastic inline filter in the feed line. Primed the system and fired it up.

So: it runs like crap. Rough, low idle, no ability to rev at all. It got better after running for about 10 minutes or so, but still has a rough idle and flooring the pedal gets a brief burp then basically it stays at idle (no rev ability at all, really). It idles so low that the alternator doesn't click the charge relay over until the pedal is depressed a bit. The good news is that the idiot lights then turn off and I get 14.5 V at the battery, so I've got charging (unless the lights not going off until its revved mean the alt is weak?).

Now, the question is: did the nasty fuel ruin the injection pump? Or, am I simply dealing with one or two clogged fuel filters? Anyone care to make odds on this one? I didn't even consider something as simple as a clogged filter until I was out of the garage and in the shower, so I was running around for about 1/2 hour convinced the injection pump was junk. But now that I think about it, the idle may have been getting worse gradually until it just died the other day. Do filters get that plugged up from rotten fuel? The old gas that came out of it went into my gas Trooper, after settling and pouring through coffee filters to get rid of the worst pollution - it clogged those up pretty quickly, so I guess all that debris was mixed with my fresh diesel and was probably going through the filters.

As always, any advice appreciated...

acy76--

Yes, filters can and do get plugged up enough that the injection pump starves for fuel. The injection pump 'lifts' the fuel from the tank, which really means that all the lifting is done by no more than atmospheric pressure.

Many folks who run bio diesel for the first time have learned that plugged filters will bring them to a dead stop as the bio detergency apparently will clean any prior gunk out of the tank and it flows to the filter.

You could just try a new filter or you could test the fuel flow with the vacuum pump and bottle method I described some where on this forum a while back, maybe in this thread.

Regards--

Paul

Hello acy76. I recommend that you purchase a new diesel filter , a clear inline fuel filter, a box of fuel hose screw clamps, some diesel cetane improver and injector cleaner and a piece of fuel line hose about 3 feet long.............get a plastic container that will hold about a gallon of fuel......secure the container under the hood and run the hose from the container to the IP with the inline filter (bypassing the main filter) and run the return hose into the container.........plug up the block heater for about 8 hours then crank the engine and let it run with fresh fuel and cleaner mix............

The basic idea with this is to work from known good values (the engine runs ok) backwards to the fuel tank(including the gas tank cap)

If the engine runs ok, then put the new main diesel filter in line with the plastic tank.........

If it still runs ok, drop and clean the fuel tank and fuel line from the tank to the engine..........

I would also install a electric pump (3-5 PSI) at the tank at this time as well......especially if you have plans to use bio diesel or VO.........

If the engine does not run ok from the plastic container.......just stop and leave it in place and report back.............

regards,
crossbones

Thanks for the advice, guys.

I am already planning on replacing the fuel hardlines and hoses (viton this time) and either having the tank cleaned or replacing the tank. So, I am going to try replacing both filters and running it from the can to see how it goes. Hopefully this is all that is the problem. I suppose it is the most likely at this point...

As to the electric fuel pump: I am wondering whether this is necessary. I was hoping I could get away without one for the sake of simplifying the fuel system. I don't think these engines were installed from the factory with any additional pumps. I also don't want to use an in-tank pump, as I'd prefer something that can be easily repaired/replaced if need be.

Is there a pump I could mount on the frame rail to supply 3-5 PSI that could be removed/replaced easily? Is this required/recommended? Pros and cons?

Thanks as usual....

Hello acy76. If memory serves me, the Carter fuel pump # is 60504 (3-5 PSI). It bolts on the frame and comes with a filter as well......

regards,
crossbones

HEY ADRIAN, ONE MORE THING YOU MAY WAN TO CHECK IF YOU HAVEN,T YET , ON THE FUEL LINE IN AND OUT OF THE INJ PUMP THE HARD LINE RIGHT WHERE IT BOLTS TO THE PUMP CHECK THE BANJO FITTING BOLT IN SIDE THE FITTIN ON MOST OF THE DSL KIEKI PUMPS THE IS A VERY FINE MESH SCREEN FILTER , IF EITHER ONE GETS PLUGGED UP WITH VARNISH THIS COULD HINDER THE FUEL FLOW AT THE PUMP ALLSO , JERRY

Thanks Jerry, I forgot about that screen. Turns out it was just a bad filter. It runs better than ever with a new filter and fuel coming from a fresh can. No more horrible smoke and rough idle, etc. Now I need to get the system cleaned up so I don't total any more $23 filters.

I think I'll be needing an electric pump - the clear inline filter was slowly emptying as the truck was idling, which seemed to me to indicate that the IP needed some supply help. To be fair, it was drawing fuel from up high (can sitting on top of radiator) and I was still using the old inline filter - they must really have coarse media, the stuff that ruined the main filter hasn't really bothered the inline filter.

Crossbones, I will check on that Carter part - as long as it isn't strictly a pusher pump (like an in-tank) it should work.

Now I need to do some oil filter research: the Wix I bought is not the right one. Seems to me someone else posted about this a while ago...

I've added a few new posts to the blog. Managed to make some decent progress so far this weekend - taking a break from the 99-degree temps to update the blog was a good idea!

What do you guys think about this fuel pump? I'd like to mount it under the hood as a lift pump for the engine. I am not sure it is entirely necessary for petro diesel, but Crossbones recommends one for biodiesel use and I think it can't hurt. If it's under the hood, I can easily bypass it if it fails.

Is 6 psi going to be too much pressure? These pump types also develop suction as far as I know, can anyone confirm? I need one that can draw from the tank while being mounted under the hood.

Thanks again for any advice.