Multifuel Engine "Skipping"

[Wildchild467]

I have about 20 gallons of WMO (filtered to 5 microns) and 30 gallons of diesel in my tank. My filters are all new spin on. The other day i started it up, let it run for about 5 minutes at 1000rpm then went over to my nieghbors house about 300 yards away. i had it idling in his driveway and it counded fine, and then the tone of the exhaust changed and sounded like it was skipping (a cylinder was not firing or not firing as good as the others). I checked the temps of the injectors and the rear 2 injectors were a little cooler than the rest by 5 degrees or so, not sure if thats sidnificant or not. what are some causes to make the engine skip? the engine was not up to temp yet, but it was running just fine. its not the first time it did this. im wondering if i have a dirty injector and it is not spraying a good stream like the others or something. I still have the original plastic fuel lines on the engine. could this be any cause for the problem? what else could make it do that?

 

[Floridianson]

Plastic lines I don't think so. Full temps to get the best burn I would think so.

 

[rrrr]

Clogged injector ? thin out your WMO more and maybe add some ATF (automatic transmission fluid - Dextron III) a few quarts to clean out the system and injectors.

Go out and run it !

 

[Wildchild467]

I agree on the temps. If all the others are working ok and one injector isnt making a good stream it may not burn as well as the others that spray good, correct? my theroy is that the WMO does not burn as well at lower temps as the diesel and maybe that is why i have a sign of a bad or dirty injector. does my theroy make any sence or should i just stick to gas engines? haha.

 

[rrrr]

It seems that guys that have problems like this are running WMO or WVO. I thought about running both but the extra filter changes needed just don't make that worthwhile to me. If I could get WMO for free I would still dilute at least 50/50. I only run diesel in mine.

 

[Floridianson]

Till the zombies come same here.

WC have you ever listen to your injectors with a long screwdriver. They should have a very clear clicking or poping sound.

Full temps. always before looking for any problem.

 

[rrrr]

Till the zombies come same here.

WC have you ever listen to your injectors with a long screwdriver. They should have a very clear clicking or poping sound.

Good idea listening to the injectors !

Waste zombie is good fuel then huh

 

[JDToumanian]

My truck does this sometimes.... I believe it is governor flutter or spring vibration, or something along those lines that I consider "normal"..... Quite a few deuces I've seen do this especially when cold.

Jon

 

[Recovry4x4]

Water will cause a perceived skip as well. Sounds like a cylinder is momentarily dropping out. I run WMO and have almost exclusively for 3 years. One filter change and still going strong despite my issue with water laden JP-8 at the FL Rally. I could never attend the GA Rally if it weren't for WMO.

 

[Wildchild467]

It makes sence with having the truck up to temp for sure, i understand that. I also understand taking the truck out and running it real good is great for these machines. I plan on attending the Rouch Creek Rally and i couldnt do it either if i didnt have WMO. i have always ran power service silver bottle in the deuce since i got it. seemd like it would be cleaned by now. i have the winter front cover on the front, so the temps are around 190 all the time. maybe the trip to RC will clean it out. I drive it to work and its about 13 miles to work, but maybe they need to be run longer than that to keep the engines "cleaned out"? My engine still likes to "hunt" sometimes when it idles, im not sure what that is all about. could it be a broken govenor spring or injectors out of balance?

 

[Jimma]

So will a little ATF really do a lot to clean the injectors? I have not tied it but am curious and may if it will help.

 

[Wildchild467]

I heard it does clean things very good for cleaning. my only thought is that there is nothing i could pour in my tank that is going to magically fix any problem. like if i have a dirty injector, i dont think they just fix themselves. example: if my injectors are not balanced correctly. when i got the truck i found that a little bit of everything was not ajusted right... like my intake fuel pump depth, a couple tight valves and my brakes (both rough and fine adjustment). this is why i feel like it would be nice to pop test the injectors and see if they are out of spec. has anybody balanced their injectors and found it helped a lot even when they thought it ran good before?

 

[Stretch44875]

Takes a 50-100 mile drive to get the mulitfuel cleaned out and running. Of the trucks I've driven, they run best when run hard and long. Both of mine can be real dogs until taken on a long trip.

Gimpy's truck had the hunting at idle problem, it went away after a couple of long trips.

 

[Wildchild467]

ok, sounds good. yea, best start with the little things and see what happens. i drove it 5000 miles last year and maybe 50 so far this year. it really never sees a 60+ mile trip on the highway ever. I could put 60 miles on it in one day but its back roads and a lot of shifting. we'll see what happens when i get down to Rouch Creek in 2 weeks!

 

[Wildchild467]

well i went on the trip and got back and the engine still didnt seem to run much better. i got about 9 mpg on the highway with the cargo cover on and cruzing about 48mph/2200rpm. I tested the temperatures on the exhaust manifold for each cylinder and found the temperatures all over the place. one was about 230 degrees, one was 300. i also used a stethiscope (spelling?) and listened to each injector. cylinders 1,2 and 3 did not have a nice ticking sound as i got from 4, 5, and 6. so i got another set of take off injectors from kublos surplus and put them on the truck. I have all the information that was on the injectors in the shop but not with me. i think they were made in 7-91 and were made in italy. they were called "something International" but i forget what "something" was. ill get the info and post that incase anybody wants to know that. but ill move on...

The injectors i took out had some crud built up on them and im not sure what it is from.... black carbon looking stuff. i dont know if its from the WMO or what. 2 of the injectors had one of the 2 holes plugged up. Ill try to get some pictures to show what they look like. i also plan on having them pop tested as-is right now to see how they spray. maybe i can make a connection to the spray patter to the difference in temperatures on the exhaust manifold.

Installing the "new" take off injectors:

i used the old copper gaskets that came with the injectors because i did not have new ones. i dont know how big of a deal that is, but maybe somebody can chime in. so i started the truck and it ran a lot lot smoother! power seems about the same. going up hills and such. the manifold temperature readings now were a lot closer to eachother than before, so we'll see what happens after i put some miles on the injectors and some power service silver bottle in the tank. maybe they need some excersize. but regardless, i am still happy with the results. just comming back from dinner tonight (today was my birthday ) and it seemed to sputter on low end acceleration.... not real noticable, but a little. i changed the 2 final fuel filters thinking maybe that was the cause, but it wasnt. i did notice some wetness around the high pressure injector lines, so i shut the truck down and tightened up the lines a little bit more.... a couple seemed a little loose. i need to wash down the engine and see how everything looks after that. I have not run the truck after i tightened up the lines, so im not sure if that was a fix or not. i do have a governor problem that i need to fix.... not sure what is wrong with that. im a little nervous taking the back cover on the injection pump off, but ill have to read up more on that issue.... the truck idles nice at 800 rpm pointing down hill, but when i have the truk stopped pointing up hill, it idles lower maybe around 700 rpm. one problem at a time unless somebody knows more about that. haha! I know this is a real wordy post, but hopefully all the information helps somebody out..... or you guys help me out. it's a support group, i get it!