First real use of Mep-803 | Praises and problems (albeit little)

[Guyfang]

I was out of the net.

The Army is strange. Some gen sets have ALL the info, gen set and engine both, in one TM. Others, not. That's why when you look at a TM number like, TM 9-2815- anything, you KNOW its an engine TM. Any TM that starts with TM 9-6115-anything, you KNOW it is a Generator set TM. Its very confusing for people who were not in the military or in a maintenance field. One reason this is so, is because the engine might be used in several different pieces of equipment. And not always gen sets. So, to save money, they break the engine out of the total package and print it separately.

 

[Light in the Dark]

Okay, apologies in advanced for my stupidity here. I feel like if you can walk me through this I should have a good understanding of how to navigate the TM's.

I'm in 9-2815-253-24.

on 3-2 (troubleshooting table) i see: Low Oil Pressure ....................................................................................................................................................3-5 \

flip to 3-5 and see:
9. LOW OIL PRESSURE.
Step 1. Check for improper grade of oil.
a. Refer to end item lubrication order. If proper grade of oil, do Step 2.
b. If improper grade of oil. Refer to paragraph 3-20.1 and change oil and filter.
Step 2. Check for engine running hot.
a. Refer to Engine Overheating, Malfunction 7, in this table.
b. If not running hot, repair or replace engine.

*insert joke about replacing engine and oil pressure still low*

What am I missing here?

Just to confirm your question was answered directly (it was over the replies that followed), but that's the diagnosis steps for the engine only. If you take the sender and all other accessories out of the picture... its a mechanical oil pump. If you have pressure issues in this engine, with that pump... the military knows its an internal concern.

Now with the steps from the genset book which I provided, its highlighting the accessory test steps for that platform. Both books can be used together if needed, but as you see... the info sets are different. Both are GOOD sets of info, but its a whole lot less likely that there is an oil pump concern in this piece of equipment, than a failing sender or gauge.

Does that help make it clearer?

 

[spotrep]

Just to confirm your question was answered directly (it was over the replies that followed), but that's the diagnosis steps for the engine only. If you take the sender and all other accessories out of the picture... its a mechanical oil pump. If you have pressure issues in this engine, with that pump... the military knows its an internal concern.

Now with the steps from the genset book which I provided, its highlighting the accessory test steps for that platform. Both books can be used together if needed, but as you see... the info sets are different. Both are GOOD sets of info, but its a whole lot less likely that there is an oil pump concern in this piece of equipment, than a failing sender or gauge.

Does that help make it clearer?

Yes this clear now! Thanks for spelling it out explicitly.

 

[Guyfang]

Its called learning by doing!

 

[FarmingSmallKubota]

Its called learning by doing!

For some reason GI JOE flashed in my head

 

[rickf]

That is why I like my 002 and 003's, Mechanical oil pressure gauges! My oil pressure safety switches have failed on all of my sets. Electronics are a royal pain.

 

[spotrep]

Okay gents I know it’s been awhile. Life is busy with the 2 kids and I’ve been at work on other generator related projects that I’m excited to show yall hopefully soon.

I’ve had the help of @kloppk a bit on the side to get my 803 oil pressure reporting accurately, but wanted to turn it loose on yall as I don’t want to overstay my welcome in Kurt’s emai, especially since he’s helping me with another project at the same time.

Here is the situation-
1.OP gauge reads ~40 psi ALL THE TIME.

2.OP sender ohms fine (need to do tm test to check ohm while running and under pressure too, will perform test tomorrow)

3. Voltage at M7-S is 9.05 V when not running and S1 set to prime/run

a. Should voltage at OP sender be same?

b. Will a bad gauge affect voltage at m7-s?

important note: I’m fairly certain my gauge is bad. I have replacement gauge already if I do need to change it. As previously stated in thread my mechanical gauge is reporting healthy OP. My main issue is that the low OP makes @kloppk control card think the engine has stalled or isn’t running.

I feel like I’m posting this a bit prematurely as there are a few TM steps I have to do. Gauge test on TM kinda came back as inconclusive as I need to pick up some gator clips to perform a proper test. Need to pour through manual and track down 130b wire that terminated at M7-s. Does that connect directly to OP sender?

I’ll post tomorrow when I’ve learned more.

thanks gents!

 

[Guyfang]

M7-S (130B) goes to J7-3
P7-3 (130A9 goes to MT7-1

 

[spotrep]

M7-S (130B) goes to J7-3
P7-3 (130A9 goes to MT7-1

Will trace those and look for damage. Thanks for that!

did test of OP sender while running and saw ~100 ohms.

moving to look for damaged wire

 

[spotrep]

Okay I’ve got it fixed!

I tried to trace down 130B and then 130a9. Was partially hoping to find the smoking gun at j7/p7, but in hindsight I’d rather not have to fix that connector.

because I could find no issues with the wire I replaced my gauge. I knew my gauge was bad, but I wasn’t certain if it would impact the reading for Kurt’s controller.
After replacing the gauge it’s reporting oil pressure perfectly.

another potential change I made that fixed my issue was I cleaned the ground connectors that mount to the panel.

You gurus may be able to pontificate on if getting proper voltage at m7-s was from the new gauge or the fixed ground- I’m just happy to have it fixed.

 

[Light in the Dark]

The gauge is the end of the line, and shouldn't have an effect on tested voltage... so it was probably cleaning up the connections.

 

[Guyfang]

Also, the bracket that holds the meter to the panel is a spot that requires attention sometimes. Its the GROUND. There is even a PS Magazine article about it. The bracket has to be "Just Right" to insure a good ground.