1982 300td dying

[scoodidabop]

My 300td wants to stall after cruising on the freeway. The cold weather is making this happen. Should I add some RUG to breathe life back into the old beast?

[vstech]

that would not be my first choice,
I would try some white bottle diesel service additive. about 1/2 a bottle on an empty or low tank just before filling the tank.
then run a pair of diesel purge bottles through the injectors, then replace both fuel filters... then change the air filter.
then change the oil and filter.
John

[bgkast]

Describe your primer pump. Is it white and requires unscrewing to operate or is it black and springs back when you press it? The old white kind can leak air and cause stalling.

[scoodidabop]

Originally Posted by bgkast

Describe your primer pump. Is it white and requires unscrewing to operate or is it black and springs back when you press it? The old white kind can leak air and cause stalling.

Hmm... good call. I just purged, changed filters etc. so I don't think that's it. But.... my primer is the white/unscrew type. It leaks like there's no tomorrow when I prime. Also, the inline clear filter doesn't look as full as it used to.

Time for a new primer me thinks!! Can anyone explain why this happens only after freeway driving? The beast does just fine between stoplights and through neighborhoods. I guess the idle is self adjusting, and the fuel pump cuts back more much after the high demand high speed.

[justinperkins]

I had that happen on my 80 TD, turned out the fuel tank was nastified and ended up having to pull it out and thoroughly clean it.

The symptom was stalling after freeway driving and the visible change in the engine compartment was lack of fuel in the pre-filter.

I was able to get it restarted, after lots of manual pumping on the priming pump, but it would die shortly thereafter. You could test this theory by hooking up a temporary fuel tank in your engine compartment (ala Diesel Purge style) to bypass your fuel tank completely. If it runs fine like that, then you've found your problem. I wish I thought of that when I went through this.

[LaughingGravy]

Justinperkins or anyone else,
In the way of replacing the tank screen, how low did you let the tank get before draining it?

[rrgrassi]

Originally Posted by scoodidabop

Hmm... good call. I just purged, changed filters etc. so I don't think that's it. But.... my primer is the white/unscrew type. It leaks like there's no tomorrow when I prime. Also, the inline clear filter doesn't look as full as it used to.

Time for a new primer me thinks!! Can anyone explain why this happens only after freeway driving? The beast does just fine between stoplights and through neighborhoods. I guess the idle is self adjusting, and the fuel pump cuts back more much after the high demand high speed.

I had the new style pump on my car when I got it, and I had to replace it, because it was leaking. I also had a prefilter crack to allow air in when the engine was running, and dripped when the engine was shut off. I had the same symptoms you had. After replacing the leaking culprits, the problem went away...

[Biodiesel300TD]

Originally Posted by LaughingGravy

Justinperkins or anyone else,
In the way of replacing the tank screen, how low did you let the tank get before draining it?

I cleaned the tank screen on my 300TD a while back. I ran the tank down as far as I could, I still had about 2.5 gallons that came out of the tank. Mostly into containers, with a fair amount on me. Since the tank lays down in the wagons you can still have quite a bit of fuel in the tank when it seem there isn't much.
I was changing my fuel lines, so I let a lot of it drain through the hoses, but I also loosened the tank screen, it's on the bottom, and drain a lot that way. If you have a large bucket to catch fuel in I would just pull the tankscreen and let it drain. Just loosen it so a little comes out not all at once. This way you can close it again when your bucket is full. Make sure you have extra buckets on hand there may be more than you planned on.
If you drain is through the hoses, take the cap off the tank so it can breath. I didn't and got the glug glug draining which is slow.

You can just clean the screen off. Just make sure it's dry before you put it back in. Make sure you put on a new o-ring. Apparently they tend to leak if you don't, and you don't want to have to do it all again, and the o-ring is cheap.

[barry123400]

Any chance the tank is doing the vacuum thing. Leave the filler cap a little loose before getting back on the interstate. Or get out and check it for an air intake sound when you loosen it just after coming off the highway. Yes the fuel vicosity might be greater with the cold weather as well. That would seem to make it harder to pull fuel against a partial vacuum as well. So the symptom would be more noticable or only occur in cooler weather.

[Sbean]

When I want to inspect my 300TD tank screen, I prepare a plug using a golf ball wrapped in a rag in a plastic bag to jam up against the hole after removing the screen as quickly as I can. I prop it up with blocks of wood or a jack. I only lose a cup or so of fuel, which falls into a wide pan underneath.
I've done this a couple of times; the screen has been almost perfectly clean. The amount of fuel in the tank is not an issue for me. Steve