M35a2 Timing

[Wildchild467]

So once the timing mark in the window is lined up, the red tooth on the HH gear should be one tooth to the rear. I havent messed with that or even checked that. 24 degrees would be quite a bit off. would it even run?

do you guys think if the pump is off that much it would effect my performance? Does the mark that is on now shows my timing is advanced too much, correct?

Maybe i should go after injector cleaning and balancing first? the engine does "hunt" sometimes at idle and maybe that could be an injector. If thats the case, maybe i should start off with that if its not too hard to clean and balance them, right?

 

[m-35tom]

see how this confuses the issue? there are only 2 timing marks and the red tooth on the HH is not one of them. has nothing to do with setting the timing, just removing the head. if your marks are lined up on the balancer and the advancer window, you are set.

i would just run a couple of tanks of injector cleaner in it and see what happens. if you remove the injectors to have them cleaned, you will find several that are not quite as good as they should be, but this should not affect the way it runs until they are really bad. bottom line is, don't remove injectors until you are ready to spend $300 having them serviced.

tom

 

[Wildchild467]

I agree with what you are saying about the timing marks. i know the red tooth mark is only for removing the HH. I have a friend that went to diesel school and he said he could borrow a pop tester so we can pop test the injectors. It would be intresting to see how they are. When i started it up the other morning, i set the hand throttle and then a couple minutes later the engine speeds up a little more (300 or 400 RPM). Im thinking this is due to the cylinder temperatures rising and more complete combustion of the fuel. could this be due to injectors not spraying in the fuel that good. i know multifuels dont atomize the fuel, they squirt it in. Im just thinking if an injector or 2 is not performing as good as the others until the combustion temperature gets a little higher. does this sound right for all multifuels or could mine have an issue?

 

[m-35tom]

the injectors do atomize the fuel if they are good.

tom

 

[JDToumanian]

After I swapped hydraulic heads on Jim's deuce (The Recorder), it was quite a bit less powerful.... I know it was done correctly, so we figured it was just a difference in parts. Tolerances / amount of wear? Manufacturing difference? It made sense that a hydraulic head change would affect overall fuel calibration. ....Whatever. We turned up the fuel to where the truck runs well. Done.

Jon

 

[Wildchild467]

just an update on this thread, i swapped out injectors with some nice looking take outs and the engine no longer hunts at idle. some of the holes on the injectors were clogged up and had some black carbon build up on them. who knows what that was all about. I think i might pull the injection pump off sometime and check the advance unit and govenor to look for anything obvious which might be causing performance issues. i have looked a long time, but does anybody know of a thread that shows how to pull off (on a work bench) the advance unit and govenor for inspection? is it that difficult? i looked at the injection pump TM, but the pictures are not that clear and i do not recall how to take it apart. new gaskets would be nice since i will be in there anyway. could a diesel shop get me the gaskets? What else would you do to an IP as far as preventative maintance while its on the bench? I think i will install new oil hoses also.

 

[Floridianson]

Good you found the bad injectors. What have you done to correct the little timming differance there is?
I myself would not pull the IP just to look and see. Correct timming if it's off and increase main fuel.

 

[gimpyrobb]

I haven't followed this thread as closely as I could have, I'm sorry. I would like to say that taking apart the advance unit will be a nightmare. I did that on accident once, good luck getting all that crap back in correctly. Also, you know you can loosen 3 bolts that holds the gear on the front of the IP to adjust the timing? Hope this helps.

 

[Floridianson]

I all so would stop pissing in the fuel tank till you get it running like the trucks willl and can. Then go back to your mixing stuff.

 

[Wildchild467]

I dont know if i should just get another injection pump or just see about fixing this one. I might pull the radiator so i can get to the timing cover and change the timing to right on where it is supposed to be. I have not done anything yet to check the timing. what would happen if the 3 bolts on the gear are loose? maybe they were not torqued correctly and that is causing me problems..... not sure. i would like to find out why it idles 200 rpm faster pointing down hill than pointing up hill. i have a feeling thats where my problem is but what part of the IP would do something wierd like that?? Another thing, if i pull my IP, i can pull the steering box and change the bushings in that also. I would feel so much better if i found something like a broken spring and would be like, "oh that must have been the problem!" and get it fixed. I dont have as much experience as you guys, but its not like these trucks are that complicated for theroy of operation. Not saying pulling the injection pump apart is easy, but everything in general. what happens if a spring in the advance breaks? the timing stays retarded and would not give me a good advance curve? when i hit a hill, it slows down to 1600 where it seems like it makes mad torque and also around where the droop screw setting is. so that makes me think like i need to turn up my fuel.... but that dosnt explain why my idle speed changes pointing down hill vs up hill. what if uncle sam backed out the high speed too much and didnt give it enough fuel? would that make it run but not be "tight enough" inside the govenor and make it idle different? i turned up the fuel 2 flats and still make the same boost. i dont want to go any more though without a pyro.

 

[Floridianson]

The radatior does not need to come out you can get to the three bolts no problem. You might not see the bolts but with a mirrior you can look then just use you hands and mind when you put the ratchett to it. The center bolt is the same way just feel for it and then turn it as needed. Are you using 5 gear low range and turning the jackshaft. I like it this way as you have more control and the balancer and moves slower. Do need soldier B to watch though.

 

[Wildchild467]

when i checked the timing, i just grabbed the fan and carefully turned the engine over. like that. i would go backward, past the timing mark. then rotate the engine in the normal direction to approach the timing mark... that way it would take all the slop out of the gears and be more accurate.

do you have any suggestions why the idle speed would be different though?

another side note... the rear bracket that bolts the IP to the side of the engine for support had 2 missing bolts on the engine. to replace the bolts, i had to loosen up the bracket on the IP to get the bolt holes to line up. when loosened up the bolts holding the bracket to the IP, the IP "snapped" back into a relaxed state. it was like they put the different IP on with that new bracket attached and cranked the bolts down to the timing cover to mount the IP without loosening up the rear bracket. i dont know if that has anything to do with anything, but it wasnt good the way it was.

 

[gimpyrobb]

I have a parts IP I could pull apart for you. I hesitate to post this as I am short on free time and I'd hate to not be able to follow through. If you think it would help, I'll try to make time to pull one apart so you can get an idea of whats inside there. Also, you can see the gear on the front of the IP without taking the rad. out, it just isn't a great view. You have to look between the rad and the rubber guard that is in there.

 

[Wildchild467]

i appriecate that gimp, but ill take one step at a time i think. ill pull the timing cover today if i have time to see if anything is loose or something. If worst case scenerio is just get another IP that looks good and bolt it up.... i just feel like thats the easy/expensive way out.... ill pull the timing cover and report back. ill try to take pictures if i can, but we'll see. another thing i could do is check the timing from the mark on the crank and the timing window when it is pointed up hill vs. pointed down hill... if the helical cut timing gears and the shaft moves forward and back a little, that could change timing/power too.... right?

 

[gimpyrobb]

Yes, but I think if they were loose you would have much bigger issues. I can't say for sure that I think the issue is the IP, but you gotta start trouble shooting somewhere!

Edit, have you had the fuel shutoff cover off? There is a rod in there that connects to something under the FDC. It is held on by a small spring clip. It swings forward and backward. The truck facing up hill might let it fall back, and the truck facing down hill might let it swing forward. This is (of course) a W.A.G.

I wonder if maybe that is loose.

 

[Wildchild467]

yea, i had that off and checked that also. that is a very good guess though! i wish i could just pull my pump all apart and inspect everything to see what it could be, but i dont have a spare pump. it would be a good learning experience for me though to take one apart real slow to get an idea how to do a future pump.

Tonight i pulled my timing cover off the front of the engine and all the bolts there were tight, so i put the cover back on. i did notice that the two 1/4-20 bolts on my lift pump (the ones safety wired) were loose! i had an oil leak for a while, not sure if its oil or fuel, but i snipped the wire and tightened up the screws. i wouldnt think that would make it do it, but at least that might fix that leak! I might be headded up to Kublos after work tomorrow to get some super rope and some other things.... ill have to see how much another pump is. it runs ok and all, but it just bugs me that something isnt right with it and i might have better performance with it if that problem was fixed. plus i really would like to post here what i found was the problem so others could have some info what made my truck run the way it does.

so my thought now with all the troubleshooting i have done is that it is not fuel and most likely, not the advance.... im almost thinking its the govenor. like you said gimp, that rod and related parts causing inconsistant fuel delivery rates.... just enough for me to notice it and drive me nuts... its a love hate relationship..... i guess being married would be the same thing huh? hahahaha!

 

[Wildchild467]

oh, as far as me saying it isnt fuel, i mean like air in the lines, plugged filter, etc....

 

[shenkmen]

i guess being married would be the same thing huh?

Nope. You can sell your truck.

 

[Wildchild467]

yea, and it wont take half my stuff with it!!

 

[JohnJuan]

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