My 93 in the sig, 227K miles.

Started last night. Runs fine down the road, cruises fine. Can hit the throttle and swing right up to 30psi and have normal power.
Sitting at idle it will stumble and run rough some of the time, just like you are pulling the shutoff lever part way. Rev it up to 1200 or so and it runs smooth.

So far:
Pulled shutoff solenoid and removed plunger, no change.
Pulled drain on bottom of filter while running, got no water, good stream of fuel comming out showing me the lift pump is pushing fuel.

Don't have a filter to put on it right now, but just don't see that being the problem since my problem is at low fuel demand times and not at higher fuel flow rates, filter only has 6000 miles on it as well.

Sugestions?
Really hope the IP is not dying, don't have the cash to mess with it right now. Will just have to park it and use my gas pickup.

Andy

 

Check to make sure you have good flow out of all the injectors while it's running.

 

Runs better cold and the lousy idle starts when it warms up, or same all the time?

 

This morning it was around 35 degrees. Started it up and it started in right away. Ran like crap at idle but would purr right down the road smooth and had the normal power I was used to. Will idle smooth for say 1 minute and then throw a fit for 10 seconds.. idle 20 seconds... throw a fit for 5.. not really regular cycle or anything.

It actually seems to get to where it is not as bad when it is fully warmed up. Once it is warm it just skips a beat once and a while most of the time. When it does it cold it will barely run. Not missing on a particular cylinder or anything.. just like you turned the idle down to 200rpm... then it pops back up to 850. There are times when even after driving 30 minutes it will almost die going through a stop light or something.

This afternoon stopped and put a new filter on in the a parts store parking lot, still doing it. I see no leaks or anything out of the ordinary. I was on the road all weekend in mixed highway driving and got 19mpg yet.

Stopped and filed it with fuel this evening, still did it again when I let it idle in the yard.

I was planing on hooking up the jeep behind it later this week for an 800 mile trip... don't know what to do now.

Andy

 

bump


could it be sucking air? Wouldn't that show up at higher speed to? dunno.
https://www.dieseltruckresource.com/...=replace+lines
https://www.dieseltruckresource.com/...e+lines&page=2

Thought of putting a few feet of hose from the LP to a bucket and letting it run, see if it does it then. Should suck fuel that way shouldn't it?

EDIT: one more thing, is there a part number or write up with o-ring sizes to rebuild the quick lock fittings at the ends of the plastic fuel lines on a 93?

Andy

 

Yes, it sounds like it's sucking air from time to time. The fuel line in a bucket of fuel is a good test.

 

I forgot to get some extra diesel to try it with

I swapped on my spare LP just to do something (25 miles back to town so will get fuel tomorrow) and no change.

This truck has the plastic line with snap ends on it. The line looks fine, but maybe one of the ends is not sealing anymore.

The local carquest has Gates hose rated for Diesel use at $.99 per foot for 5/16. Seems like 5/16 fits the existing fittings pretty well. I hope it is that and I don't have to tear the tank appart!

Andy

 

success!! Started up and ran smooth this morning. No stumbling or bogging.
Kind of interesting that there were already an extra set of clips along the frame that were like they were made for this purpose. Maybe they knew their design would be a PITA after 15 years and were nice to the tinkerers.

I just bought some $0.90 a foot gates hose to get it going. I will want to switch to something better as I have had short life from it in the past. Seems to only take a year to crack. Sugestions on where to get something good? Might as well upgrade the size while I am at it, 3/8 or maybe 1/2".

Andy