MEP 805B

[MSAL]

I am new to this game, I bought a MEP 805B I am looking for a mechanic in the Sacramento area . anybody have any ideas ?

Thank You

 

[Guyfang]

What is wrong with the set.
Have you downloaded the TM's
Have you read the operators instructions?
Have you ever seen it run right?

 

[MSAL]

What is wrong with the set.
Have you downloaded the TM's
Have you read the operators instructions?
Have you ever seen it run right?

I replaced the CIM, I can start it by bypassing the fuel cut off switch. It runs over voltage. I replaced the motor governor, and voltage regulator with used parts.
I do not know how to check if the used parts I am getting are good or if its something else. I would rather not just keep throwing used parts at it .

Thank You

 

[Guyfang]

Could be the MPU. Open the -14 TM and read about the below listed suggestions, if the red light is lit on the A3, (speed control).




Remove, clean, check IAW, (in accordance with) the TM and reinstall, (if the MPU is good) and readjust the MPU. Then try starting.

 

[155mm]

What said, mpu.

i have always said, if it wont start check mpu, if it runs out of fuel, check mpu, if there is a rod thru block, check mpu, get it? Mpu is the only connection between engine and and computers

also does it look like some one dinked with the injection pump and governor assy on top of it?

you said you bypased fuel cutoff, explain what you did.

The fuel cutoff/ governor assembly is the throttle also, thhat works with the mpu to maintain rpms therefore maintaining stable hertz under inconsistent loads

 

[Guyfang]

What said, mpu.

i have always said, if it wont start check mpu, if it runs out of fuel, check mpu, if there is a rod thru block, check mpu, get it? Mpu is the only connection between engine and and computers

also does it look like some one dinked with the injection pump and governor assy on top of it?

you said you bypased fuel cutoff, explain what you did.

The fuel cutoff/ governor assembly is the throttle also, thhat works with the mpu to maintain rpms therefore maintaining stable hertz under inconsistent loads

What he said

Great minds think alike!

 

[MSAL]

Could be the MPU. Open the -14 TM and read about the below listed suggestions, if the red light is lit on the A3, (speed control).
View attachment 823110
View attachment 823111


Remove, clean, check IAW, (in accordance with) the TM and reinstall, (if the MPU is good) and readjust the MPU. Then try starting.

The Actuator light is not coming on while cranking , That is why I replaced the speed control. I got the engine stated by running a wire from the battery to the electric actuator.
Would the MPU keep the light on the speed control from coming on?

 

[Guyfang]

Yes

 

[MSAL]

Yes

I took out the MPU, Cleaned it , reinstalled it per instructions (bottom out then back out 1.5 turns) it did not solve the problem. I will next test the MPU and see what that tells me.
Is there anything else I should look for?

 

[155mm]

Loose connectors on the back of the control module,

i had a problem child that didnt want to work right, so i removed control box from genny, sat down in the shop, removed all components from back plane, inspected connectors, cleaned with air, reinstalled and it fixed all the problems,

not saying its your fix but, its another option

Check that the wire connection is good at the governor, i had one of those fail also

 

[155mm]

Here is the tm for the governor

MEP 805b 806b electric fuel cutoff tm/troubleshooting/install manual.

did you adjust the mpu when reinstalling? Or just 1.5 turns out and stop?
There is a procedure in the tm for mpu adjust

have your searched and read the other threads on mpu’s?

 

[MSAL]

Here is the tm for the governor

MEP 805b 806b electric fuel cutoff tm/troubleshooting/install manual.

did you adjust the mpu when reinstalling? Or just 1.5 turns out and stop?
There is a procedure in the tm for mpu adjust

have your searched and read the other threads on mpu’s?

I just did the 1.5 turns. I will look up how to adjust the MPU .
Thanks

 

[Guyfang]

I was just going to ask you what output you are getting from the MPU. But thats part of the adjustment, and 155 got you started down that road. No output from the MPU, makes a gen set a large paper weight.

 

[Guyfang]

Loose connectors on the back of the control module,

i had a problem child that didnt want to work right, so i removed control box from genny, sat down in the shop, removed all components from back plane, inspected connectors, cleaned with air, reinstalled and it fixed all the problems,

not saying its your fix but, its another option

Check that the wire connection is good at the governor, i had one of those fail also

The "B" models are famous for this kind of thing. Checking connections can often solve lots of problems.

 

[MSAL]

I was just going to ask you what output you are getting from the MPU. But thats part of the adjustment, and 155 got you started down that road. No output from the MPU, makes a gen set a large paper weight.

So I tested the MPU, It started out at 2 volts, I adjusted it down to 1.33 volts. Still no cranking light on the speed controller. Should there be any lights turned on at the speed controller when the master switch is on but before cranking ? the test and reset button on the speed controller should it do something while the machine is not running?
Thanks

 

[Guyfang]

This help any?

 

[frank8003]

This help any?

Well that is just about gorgeous!

 

[MSAL]

This help any?

YES! This will help, I know on page 2, my DC power light is not on. This gives me a place to start.

Thank You

 

[MSAL]

Well that is just about gorgeous!

Following the steps on table 4-4, I have 23 volts to pin 9, ( the battery might be a little low) But I only have 1.2 volts on pin 8 . it says next step is to replace the I?O interface. Is there a way to test the I/O interface ? I don't want to blindly keep replacing parts for something I am not sure if it is any better then what I take out.

Thank You

 

[Guyfang]

Sadly, no. Thats one of the major problems with B model sets. Its "luck and chuck".

And these sets are very picky. If the battery's are low, things just do not seem to work right.