Multiple issues. Coincidence or related?

[MontanaJack]

So I towed my 1979 bumper pull camper this weekend. It's 27' long and weights approximately 5500lbs. When I got to my destination I realized I'd cracked the fuel line that feeds the fuel filter. Fuel everywhere! So I fixed it and then started noticing things.... On my trip down, smoke was at a minimum. Really the best I've seen it yet. I cruised about 60-65 at 600 degrees egt. On the way back it smoked like crazy. White smoke. And I was lucky if I could get to 60mph. Had enough power but egts were too high. On flat ground 55mph = 6psi boost and 900 degrees egt.

The glow plugs are new.. Month old. And the injectors and return lines were all replaced last week.

Timing? Air? IP? Fuel filter?

It's a 1991 250 manual, with the banks sidewinder.

Also I ran it hard without the trailer when I got back. Egts were still high but I noticed at WOT boost would hit 10 as normal, rpms would rise quickly, but not my speed. Could it be the clutch even though it's a manual?

 

[BDCarrillo]

How did you fix the hardline from the lift pump to fuel filter head?

Rpms running up would indicate clutch slippage

I've noticed some batches of WMO smoke a bit, did you switch tanks(assuming wmo blend in both) for the return trip, or use D2?

 

[laserjock]

Mechanical or electric fuel pump? X2 on how did you fix it?

 

[MontanaJack]

I ran WMO most of the way there. I keep the rear tank full of D2 to clear the lines before I park for the night. I ran mostly D2 on the way back.

I replaced the hard line with a high pressure bio-fuel safe rubber hose. IIts a rubber line From the tank to an electric lift pump so I figured a rubber line would be fine for the 16" to the filter.

 

[laserjock]

Maybe you've had the leak a while and you are finally getting full fuel pressure messing with timing?

 

[ironworker40]

Better put another batch of that wmo in it and see what it does. My gues is same as lazerjock or plugged filters

 

[madpogue]

So it ran worse when you switched to the rear tank to run the D2? Maybe a restriction (broken showerhead) between the rear tank and the selector?

Clutch/tranny issue would be very obvious; not just weak power, but the engine would be spinning out faster than the corresponding road speed.

 

[junk]

Maybe you've had the leak a while and you are finally getting full fuel pressure messing with timing?

This was my thought also. I'd check my pump timing and stuff to verify it's correct. Hitting high EGT's quickly makes me think too much fuel. Like you were starving before and now that it's fixed your good.

Also could it be a bad batch of WMO that had low rating thus being doggy? I'm not up on burning WMO, but if you burned D2 on the way home maybe it's got a higher cetane rating thus more heat? (Pulling idea out of ass.)

 

[MontanaJack]

The D2 didn't run better or worse I ran both WMO and D2 down and back. I just ran:' MORE D2 than oil on the return trip. And it didn't matter which one I used, they both smoked and had high egts.

I preferred the way it ran before. It had more than enough power and low egts. Now I still have good power but really high egts to the point I can't use the power I've got. high empty and way higher towing.

 

[laserjock]

Sounds to me like you need to stick a fuel pressure gage on there and see what's going on. If the only thing that changed was a piece of line, it's got to be related to that in some way. You either shook some crap loose or there was a restriction in the line that you removed or something got into your pump. Really sounds like timing has changed to me and fuel pressure can do that. What epump are you running?

 

[MontanaJack]

I'm not sure what epump I'm running, it was installed before I bought the truck. I think you're right about the new fuel line affecting the fuel pressure. I advanced the timing about four degrees I'd guess. It was already advanced about two with the old injectors. Big improvements! Dropped the EGTs a lot, much less smoke, and starts much easier as well.

I still have light white smoke at idle even when warm and next to no black smoke at WOT. I'm wonder whether I should advance it more, or turn the fuel screw in a flat or so.

Thanks for all the advice.