Deuce low power.

[metalworker393]

How is everybody doing, well I hope. Okay, I have reading through the TM's and searching posts for some guidance. I have gotten my A2C on the road and I am not real happy with its performance. It sat in my backyard for a few years while I had my other deuce on the road. Sold that one last year and finally have this one on the road.
Before putting it on the road I put new filters on the engine and fuel system. I eliminated the manifold heater after the problems I had with the other truck. Here's my gripe. The truck is a dog going uphill with nothing in it. I had to rebuild the turbo as it was leaking oil out onto the starter. Its a 3ld 305 model (schwitzer) took care of that oil leak. Don't know how good that turbo is compared to any other.
I have been running a fuel system lubricant to try and compensate for the low sulfur diesel. There was a lot of crud in the canisters when I changed the fuel filters. Last week I was checking to see if perhaps I may have clogged injectors. Cylinders 1-4 as I cracked the supply line loose on the injector (while running) there was an audible difference in the engine. Not so much on cylinders 5 & 6 though. Perhaps the injectors need changing?
I have been reading some other posts and maybe the HH is in need of replacement? It's not leaking out externally and not internally either. At least I don't think so because the oil level is not increasing. Some post people suggest putting sea foam in the fuel system to clean it. I have also heard of people putting auto trans fluid and Marvel oil in their fuel system.
After reading through the TM's and searching for low power or poor performance I haven't really found an answer as to why my engine is so low on power. Anybody else have this problem and wants to chime in feel free to. Just trying to get my multifuel to run like the other one I had. Thanks and Merry Christmas, have a safe holiday to everyone. metalworker393

 

[61sleepercab]

Your answer may be with your cracking the fuel lines on #5 and 6 and nothing changed. Those injectors may be low and those cylinders may be loafing. There fore you have a 4 cylinder engine running where a 6 ought to be. Can you try a infra red heat gun and check the heat at the manifold?
I had a B Model Mack that had coffee grounds in the filter and ran like a scalded dog with a filter change. You remember that the Army convoy speed was like 35 so these trucks were never overpowered or speedy.
You may need to pull all injectors and have them bench tested for pop off and fuel spray pattern. Good luck Mark

 

[Warthog]

Did you change all three filters?

 

[gimpyrobb]

Many that have been in the hobby for years have stated that the injectors are the first place to look if you have poor performance. I agree with taking them and having them pop tested/rebuilt. I also feel it is important to make sure you don't destroy anything while tuning the motor. I'd say a pyrometer is high on the list of things to install. It will give you a baseline for your motor's performance. After you do these things, its time to turn up the pump.

 

[metalworker393]

Hey fellas, yes I changed all three of the fuel filters, and a new air filter. Also went over the valves and checked the clearance as per the TM's. They were all way out of adjustment. Have the rockers adjusted now, and also new oil & filters were installed when I was ready to register it. Say perhaps I do change the Injectors. Would there be any risk of contamination coming from the HH and clog the new injectors? Or does that seem unlikely as I have put at least a hundred miles on it since I put this truck on the road. Thanks metalworker393

 

[jdmcgowen]

I had that problem with my old deuce and found the lift pump in the fuel tank to be the problem. Changed that out, it ran good again. Make sure it's delivering fuel to the IP. It can run with a bad LP. Not sure if anyone else would agree though. Just an uneducated shade tree here.

 

[gimpyrobb]

I doubt it. The IP is a positive displacement pump. Fuel will move SOMEWHERE. When I did head gaskets on my truck this fall, I also pulled my injectors and was amazed at how low of pressure they "popped" at. The TM says take out injectors should pop at 2800psi, some of mine popped at 1500! The higher pressure, correct spray pattern, and atomization of fuel will help complete combustion of fuel and increase power a lot.

 

[gimpyrobb]

I had that problem with my old deuce and found the lift pump in the fuel tank to be the problem. Changed that out, it ran good again. Make sure it's delivering fuel to the IP. It can run with a bad LP. Not sure if anyone else would agree though. Just an uneducated shade tree here.

Some trucks this holds true, some it doesn't. Usually, there is fuel line issues if thats the case.

 

[Jeepsinker]

I agree. It will almost always be the injectors or the lift pump if you have already changed the filters. You could pull the pump assembly and check the pickup screen for clogging by large particles. That won't cost you anything and is a good maintenance check.

 

[Jeepsinker]

And take a look at the fuel line crossover bolted to the bottom of the front crossmember under the radiator. They get crushed or kinked sometimes.

 

[metalworker393]

Hello and happy new year to you all. Okay so last week I changed the injectors out, Cylinders 1-4 appear to be working. A little carbon build up but working. Cylinders 5 & 6 however one of the two holes in each injector appear to be plugged. So I changed them out with a set of new ones I had bought. I didn't get to drive it until the next day. I did get more power. But I'm still looking for a little more. The other truck I had seemed to have a whole bunch more of get up and go.
This weekend weather prevailing, I am going to check the fuel adjustment screw on the IP. Supposed to be .150" screw sticking out. If it is close to that dimension I may turn it up a flat or two. If I read the sticky on turning up the fuel correctly the screw does not turn but the lock nut and jam nut are turned while holding the screw stationary. No I don't have a pyrometer yet. no I don't have a boost gauge either. Both are on the do list. Good day to all metalworker393

 

[gimpyrobb]

Sounds like you got it!

 

[rustystud]

Hello and happy new year to you all. Okay so last week I changed the injectors out, Cylinders 1-4 appear to be working. A little carbon build up but working. Cylinders 5 & 6 however one of the two holes in each injector appear to be plugged. So I changed them out with a set of new ones I had bought. I didn't get to drive it until the next day. I did get more power. But I'm still looking for a little more. The other truck I had seemed to have a whole bunch more of get up and go.
This weekend weather prevailing, I am going to check the fuel adjustment screw on the IP. Supposed to be .150" screw sticking out. If it is close to that dimension I may turn it up a flat or two. If I read the sticky on turning up the fuel correctly the screw does not turn but the lock nut and jam nut are turned while holding the screw stationary. No I don't have a pyrometer yet. no I don't have a boost gauge either. Both are on the do list. Good day to all metalworker393

Did you actually "pop test" them ? or just did a visual inspection ? To really determine the cause of your problem you need to know that all the injectors are working correctly. At work we change out the injectors every 25,000 to 50,000 miles (depends on make of engine) like clockwork . This keeps the busses running in top from, which uses less fuel .

 

[Jeepsinker]

I need to find a good injector shop around me and have a couple sets of injectors pop tested and set. It may not matter on my current engine as I believe that I now have a cylinder burning oil after this last roadtrip, but I definitely want to get the injectors in my LDS set before it goes in.

 

[metalworker393]

Haven't found a shop nearby to pop them for me yet. Very interested in what the pop pressure was on them in addition to making sure both holes are squirting. The one hole on each of 5 & 6 cylinders appears to be plugged. This truck sat in my backyard for about 5 years while I was using the other one. probably didn't start it for at least 2 years at one point.

 

[metalworker393]

Hello and how is everyone today. Well I have been contemplating turning up the fuel on my deuce. Haven't gotten the pyro or boost gauge yet so that's still on hold. In the mean time, i was reading through the sticky on turning up the fuel and the idea of bypassing the FDC kept getting mentioned.
So, having a couple hours today to kill, I decided to do the bypass and see if it really would make a difference. i even went on youtube there are a couple of video's of people doing it. Let me tell you something, the truck is running like night and day. I pulled out of the driveway and right then I could tell the power increase. Drove it around town and up and down a few hills. Unbelievable difference in the power output. I'm still glad i changed the injectors but if your multi is running like a slug and you've changed the filters checked fuel pressure and still not satisfied. You might want to try this. What a difference!
Have a nice weekend to all metalworker393

 

[Floridianson]

Doing real well today hope you are too. Yep bypass was easy right and looks like it brought a smile too your face. Now get a pyro and maybe you can turn it up more and drift around corners.

 

[DavidWymore]

Doing real well today hope you are too. Yep bypass was easy right and looks like it brought a smile too your face. Now get a pyro and maybe you can turn it up more and drift around corners.

It helps if you're on hard dirt and don't have a bed on the truck! ;-D

 

[gimpyrobb]

It helps if you're on hard dirt and don't have a bed on the truck! ;-D

Or ice...

 

[metalworker393]

Okay I do have a question about the FDC. With such a power gain could it be that the FDC was ether set improperly, intentionally set to keep the power low or could it be malfunctioning and need of service. Just wondering if this part goes bad and has to be serviced or once it is set that's it for life. I don't know as I was in the Navy and the only experience I had with a deuce was when I was in Littlecreek TPU before being flown to Gitmo. While at TPU I was working the See Bee's there and a deuce was one of our work trucks.
Have a great day metalworker393