More driveability issues

[thedrip]

Now it's an off-idle stumble. It's a whole lot like driving a gas engined vehicle with an oversized carb. stab it, and NOTHING. stab it and hold it, it sits for a second, then takes off like a raped ape. Makes driving it around town a little fun.

86 6.2... running normal ULSD w/ about a quart of tranny fluid for every 10 gallons of diesel.

Truck drove fine for a long time. lift pump is only 500 miles old.

 

[Wrench]

If it drove fine for a long time, what did you change?

 

[MaxPF]

Now it's an off-idle stumble. It's a whole lot like driving a gas engined vehicle with an oversized carb. stab it, and NOTHING. stab it and hold it, it sits for a second, then takes off like a raped ape. Makes driving it around town a little fun.

86 6.2... running normal ULSD w/ about a quart of tranny fluid for every 10 gallons of diesel.

Truck drove fine for a long time. lift pump is only 500 miles old.

That's a lot of tranny fluid. 1 qt. of ashless 2-stroke oil per 20-25 gallons would probably be better. Better yet would be actual additives designed to improve diesel's lubricity.

How many miles are on your IP? As a general rule the IP and injectors should be rebuilt every 100k-150k miles. That is the diesel version of a tune-up

 

[thedrip]

Injectors are under 60k, IP is unknown. The IP had been taken off the truck, so I bought another, but unknown mileage. Maybe it's just getting tired. Odd that it went from just fine to showing all kinds of trouble signs in under 500 miles though.

As for what I changed recently.. not a damned thing. Really. Not the "I swear I didnt touch anything" computer tech support nothing either. The real nothing. I get in it and drive, thats about all I have time for these days.

 

[MaxPF]

You might have got a bad lift pump. Or a clogged fuel filter. I agree that IP's rarely act up suddenly - it is usually a gradual degradation.

 

[AJMBLAZER]

I was reading something lately about ATF and diesels. All the additives in it now aren't really friendly to engines. ND30w, 2 stroke oil, and biodiesel were all listed as FAR better additives.

 

[Volare]

I was reading something lately about ATF and diesels. All the additives in it now aren't really friendly to engines. ND30w, 2 stroke oil, and biodiesel were all listed as FAR better additives.

x2 on what AJMblazer said.

 

[thedrip]

Well, I have somne additional info. I know where the bog comes from now, I think, or at least a byproduct of it. With someone following me with their headlights on, it's 100x easier to see how much smoke I'm making... off the line... hit the pedal, nothing nothing, HUGE cloud comes out, then thins out to normal levels as the truck takes off. Almost is behaving like it's almost flooding from some kind of throttle change enrichment circuit or something.

 

[MaxPF]

Diesels don't have, nor do they need, enrichment devices. Did you check the fuel filter and lift pump???

 

[thedrip]

lift pump is moving plenty of fuel. I took the air bleed plug out of the filter, and blew diesel oil all over the place. Filter is about a month old, but it fixed the last problem, so I'll try a new one again. I know theres no enrichment device, I said it's acting like it though.

 

[MaxPF]

lift pump is moving plenty of fuel. I took the air bleed plug out of the filter, and blew diesel oil all over the place. Filter is about a month old, but it fixed the last problem, so I'll try a new one again. I know theres no enrichment device, I said it's acting like it though.

Something else to check is your fuel return line. Make sure it isn't blocked. If that is OK, it pretty much narrows things down to the IP...