Engine lost Power

[USN_Green_Addict]

During my road trip, half way through I noticed a lack of power, or what I perceived as a loss of power. When I had my M35A2 in Colorado I would be constantly be watching the EGT gauge, I never needed to floor the go pedal and after my intake swap it was go 60mph on 12.00-20s up gradual hills. Now that I'm in Georgia it feels like it struggles to go up hill, and I don't think I have enough power to install the Waterloo overdrive. I have checked the newer parker lift pump and it's humming just fine. I've changed the fuel filters, and last month I rebuild the hydraulic head. I do have a leak coming from the boost pump area. I'm debating taking out the entire IP to see if there are any issues or if the boost pump is bad, unfortunately I'm trying to find information On how to tell if the boost pump is bad. Previous owner installed a tiny air filter that was really bad making very high EGT, I installed a M52 filter and it dropped EGT significantly, and I was able to achieve better performance. Now when climbing any hill the truck struggles, however with my foot to the floor the EGT will never go above 1050 degrees. Or if the change in altitude and humidity affects the engine performance. Altitude was 5400+ ft in Colorado, now I'm at 305. Humidity is now in the 60+ every day. I'm not sure if I need to perform a valve clearance adjustment, or how to tell if it's needed. Blow by is very minimal out the slobber tube.

Anything else I can check?

 

[gringeltaube]

Anything else I can check?

Sounds like your engine is starving for fuel.

I'd recommend downloading and study this TM....
(Best step-by-step guide to help determine what is causing that lack of power of your Multifuel.)

 

[USN_Green_Addict]

Sounds like your engine is starving for fuel.

I'd recommend downloading and study this TM....
(Best step-by-step guide to help determine what is causing that lack of power of your Multifuel.)

Thank you,

The only thing I forgot to mention is I have the spin on fuel filter adapters. I use Donaldson water separator and Fleetguard fuel filter.

I'm not sure if these restrict flow. One is 2 microns the other is 5 microns. However I just replaced these.

 

[cattlerepairman]

Thank you,

The only thing I forgot to mention is I have the spin on fuel filter adapters. I use Donaldson water separator and Fleetguard fuel filter.

I'm not sure if these restrict flow. One is 2 microns the other is 5 microns. However I just replaced these.

I got bitten by the "but I just replaced these" a couple of times. Who knows...several fillups and hours of vibration might have shaken some crud loose you didn't even know you had in there.
I strongly agree with re-visiting the basic culprits before tearing into the complex stuff!

Sent from my SM-G991W using Tapatalk

 

[USN_Green_Addict]

I got bitten by the "but I just replaced these" a couple of times. Who knows...several fillups and hours of vibration might have shaken some crud loose you didn't even know you had in there.
I strongly agree with re-visiting the basic culprits before tearing into the complex stuff!

Sent from my SM-G991W using Tapatalk

Good news I have a spare IP, and injector nozzles. I've been pondering replacing all of the fuel lines anyway, I figure after 58 years it might be time. If I do I probably will take off the filter bases and clean those passages too.

 

[USN_Green_Addict]

I got bitten by the "but I just replaced these" a couple of times. Who knows...several fillups and hours of vibration might have shaken some crud loose you didn't even know you had in there.
I strongly agree with re-visiting the basic culprits before tearing into the complex stuff!

Sent from my SM-G991W using Tapatalk

Any idea where I can find the fuel flow rate needed for the M35A2 LDT?

 

[cattlerepairman]

Any idea where I can find the fuel flow rate needed for the M35A2 LDT?

Yes, it is in the TM. I know there is a table in the engine rebuild TM.

Sent from my SM-G991W using Tapatalk

 

[USN_Green_Addict]

Yes, it is in the TM. I know there is a table in the engine rebuild TM.

Sent from my SM-G991W using Tapatalk

Ok I found the table, however I'm not understanding unit of measurement to GPH or GPM.

 

[HDN]

Ok I found the table, however I'm not understanding unit of measurement to GPH or GPM.

Perhaps I can help with this and include a math lesson for those who need a refresher The answers are in green if that's all you want

According to Hometowne Energy, diesel fuel weighs about 7.1 lbs/gal. It seems you need GPH or GPM. I'll start with GPH here since the units in the TM are using hours. We'll use the 90 lbs/hr figure in this example:

90 lbs/hr * gal/7.1 lbs = ?

I flipped the 7.1 lbs/gal to gal/7.1 lbs because we want the lbs to go away since we're interested in the gallons. This way the lbs cancel each other out (this is easier to show as fractions on paper!). We're also multiplying fractions here, which involves multiplying the numerators and denominators together. Remember that multiplication like this isn't just with numbers, but also with units. It's algebra at work!

90 lbs/hr * gal/7.1 lbs = ?

So we now divide 90 gal / 7.1 hrs and get 12.7 gal/hr


Now if you need gal/min, we want the hrs to go away and put mins there instead, so it works like our first conversion from lbs/hr to gal/hr:

12.7 gal/hr * hr/60 mins = ?

The hrs cancel each other out and you end up dividing 12.7 gal by 60 minutes:

12.7 gal / 60 mins = 0.2 gal/min

Note that when units cancel each other out, a number "1" sits in place of the units, so that ultimate gal/min answer is really figured out by multiplying 12.7 gal/1 * 1/60 minutes. Multiply the numerators and denominators together to get the answer.

This hobby involves math sometimes. Gear ratios and fastener torque conversions are especially fun! I hope this helps to get you back on the road!

 

[USN_Green_Addict]

Thank you I appreciate it. I'm used to dealing with math on the electromagnetic spectrum, just not fluids and flow/hydraulic or pressure.

 

[HDN]

Thank you I appreciate it. I'm used to dealing with math on the electromagnetic spectrum, just not fluids and flow/hydraulic or pressure.

Different math for different things! For my line of work I do a lot of unit conversions. kWh to MMBtu to therms to gal per MMBtu, and across different types of fuel... People deal with energy in a lot of ways!

ANYWAY for the LDT it looks like you need 64 lb/hr. So that would be 9 GPH or 0.15 GPM.