MEP002A Intermittant Issue

[BEEMAC]

Sometimes (not all the time) when I start my MEP002A the low oil pressure over-ride doesn't work. I have to walk over and physically push up the solenoid just a bit. Then when I go back it fires up.

Yes it does stay running once oil pressure is built.

What would cause the low pressure override to be intermittent?

 

[cuad4u]

I am not 100% sure exactly what your problem is. If the solenoid that retracts and lets the IP throttle arm move up is not retracting or is not retracting fully, the engine will not get fuel and it will not start. If the solenoid fully retracts but the IP arm does not move up freely, the problem is probably varnish etc inside the IP which is binding the IP arm. I do not think the solenoid is meant to be repairable, but some on this site have had success spraying the solenoid shaft with PB Blaster and working it up and down. Several months ago a poster wrote a thread about removing the solenoid, opening it up, and repairing it. If the solenoid is not retracting, you may do a search. I think one of the two things I mentioned above is probably your problem.

PS: I had a 002A that the throttle linkage was binding where it goes through the oval hole in the sheet metal above the IP. Even though the solenoid retracted the IP arm would not move. A bit of filing the hole with a rat tail file did the trick.

 

[BEEMAC]

I will double check with my multimeter during cranking. When I observed during cranking and failure to start the solenoid did not retract. I considered lubing the solenoid plunger but decided against after I determined its an intermittent issue. It appeared as though the solenoid wasnt getting power during the intermittent issue.

As for the linkage, it works very smooth. No issues with the linkage itself. Issue is either lack of power to solenoid during low oil pressure overide or an issue with solenoid itself. I did check power to solenoid when unit is running but did not check it while cranking. Solenoid does have power and is retracted while unit is running.

 

[jamawieb]

If the solenoid is not retracting when starting, it's not the low oil pressure switch. The oil pressure switch only takes effect after you release the master switch from start. It sounds like your having solenoid issues only. Check you grounds first, I've had two units where the solenoid would not retract. I spent days on the first one trying to track down the problem and finally found if I put another ground on the solenoid, it would work perfect. Then on the second unit, same problem and I put a wire on the ground post of the solenoid and ran it to the bolt that holds the solenoid down (creating another ground), it worked.

 

[BEEMAC]

I will double check the ground this weekend when I have time and let you know what I find. While I am at it I will also check voltage to solenoid while its cranking.

 

[Keith_J]

The switch is known to go bad. It is vented to atmosphere and this lets water in, causing corrosion. So they stick or have issues at times.

 

[BEEMAC]

Keith are you referring to the main switch of the unit?

 

[Keith_J]

Keith are you referring to the main switch of the unit?

Yes. The circuit diagram on top shows connections. Low oil press override is only in start position. WD 40 won't hurt.