I haven't driven my truck a whole lot since I redid the head gaskets. During that process I removed the IP of course and the IP Gear. I think I got it lined up back right, using a pick to feel the timing mark. When reinstalling I pop tested all my injectors and they sprayed conical and at the same psi.

Since then I've been experiencing low power quite often. It gets worse the longer I drive it. For example I drove it down to Iowa from Minnesota and about 50 miles in the power started sucking (couldn't keep it at 70 unless it was really flat or downhill). Eventually, when accelerating from zero, the truck surges really bad (like physically bucking) when I'm moving through 3rd gear, and surges a little in 4th but smooths out by 5th gear, but doesn't give me that full power.

200 miles into the trip I'm starting to worry I might not make it.

If I floor it i get no black smoke (I hear I should be getting that). The IP is already about a 1/8 inch advanced from the marks on the housing.

After the cold idle switch turns off, the truck is idling at 600 or so. After driving it a while, it bogs down to 500 when idling.

I run WVO through it, and my system has worked flawlessly in the past.

I put on new fuel filters, new air filter.

Probably not related, but new batteries and glow plugs.

Is this a fuel quality issue? Lift pump issue? Faulty Injection Pump? Incorrect injection pump timing?

 

Surging is often a fuel supply/air intrusion issue. I'd probably start by running a tank of diesel through it (with a new fuel filter) and see if it still happens...

 

I bought a new filter, and ran diesel through it only. It still was surging and low idling.

I adjusted the injection pump so lines on the housing were closer, almost right on. Previously it worked better with it more advanced, but now it seems to run better with the lines more matched up.

Seems to be working. I'm going to drain the WVO tank and refilter all my WVO and make sure there is no water in the WVO tank and see if I can go back to using WVO after I run a tank of diesel through it.

Thanks.

 

a blocked ip return line could do this also.

 

I've check that valve on the top of the IP to make sure it is clear and functioning.

I keep moving the pump little by little, and trying to find the right spot. I think i got it pretty close, but still when I full throttle it doesn't push black smoke. I want that black smoke! Am I foolish?

Still have trouble maintaining high speeds greater than 55 when traveling up hill, and it is slow to get there. Maybe this is normal- but I feel like I should be able to do better.

Any suggestions? I have 2 extra injection pumps... worth a switch? Or is my timing still not dialed in?

 

Have you tried switching to the other tank, diesel, to see the surging goes away? My front tank has issues after about 30 minutes of driving..

 

I tested the pressure at the fuel filter and I got 4psi, so i ruled out the lift pump as being a problem.

Another mechanic I talked to said if it starts and has air going in and out, then it probably isn't compression.

That left the IP or injectors. He felt the IP is more likely since I recently tested all my injectors and they were about even.

So I spend the afternoon swapping the IP, and low and behold-

More power, quieter and more even idle- no smoke.

I was even able to accelerate up hills!

Now with the old one, the symptoms would worsen with a longer drive, so I'll have to be a bit guarded in my optimism. But, this seems to work.

Thanks to C at B truck and trailer in W, Iowa for the $100 IP!