Yanmar 2QM15 idle problem - desperate

gqmf · #1 (**permalink**) 02-11-2012

Hi; I'm new to sailnet but am hoping some of you could shed some light on an issue I'm having with my Yanmar 2QM15.

I just had my fuel injection pump rebuilt; just put it back in and started the engine. What happens is that she now idles at max RPM; now the morse cables are disconnected which pulls the fuel control rack (in the FIP) to the back of the engine but shouldn't this position/setup be the idle position not the full throttle position? ie if a morse cable erre to fail, surely the engine wouldn't just rev up to max rpm, right?

Then I noticed that pulling the fuel control rack forward (thus by pushing the regulator lever back) reduced the rpm's... which to me seems is strange as this position would be with a retracted morse cable to the control lever.. which is my "Forward" position... I'm hoping anybody still follows me. Problem here is that a "mechanic" worked on this engine so I have no clue what he did; as when I returned from work I saw him taking apart the FI pump... which is when I knew he was clueless and consequently needed to have it rebuilt.

I'm really hoping some of this rings any bells to any of you as I'm really about to give up...

fryewe · #2 (**permalink**) 02-11-2012

gqmf...you got the 2qm15 tech manual? If not, perhaps I could scan the appropriate drawings for you and send them. The setup ain't rocket science, and with the TM you should be able to get this corrected.

gqmf · #3 (**permalink**) 02-11-2012

Thanks; I've got it in HC; just confused by this and still can't figure it out... and its not like its the first yanmar engine I've ever worked on... :-( so was hoping somebody had dealt with this before... hopefully give me a pointer or two...

FarCry · #4 (**permalink**) 02-12-2012

Quote:

Originally Posted by gqmf

Hi; I'm new to sailnet but am hoping some of you could shed some light on an issue I'm having with my Yanmar 2QM15.

I just had my fuel injection pump rebuilt; just put it back in and started the engine. What happens is that she now idles at max RPM; now the morse cables are disconnected which pulls the fuel control rack (in the FIP) to the back of the engine but shouldn't this position/setup be the idle position not the full throttle position? ie if a morse cable erre to fail, surely the engine wouldn't just rev up to max rpm, right?

Then I noticed that pulling the fuel control rack forward (thus by pushing the regulator lever back) reduced the rpm's... which to me seems is strange as this position would be with a retracted morse cable to the control lever.. which is my "Forward" position... I'm hoping anybody still follows me. Problem here is that a "mechanic" worked on this engine so I have no clue what he did; as when I returned from work I saw him taking apart the FI pump... which is when I knew he was clueless and consequently needed to have it rebuilt.

I'm really hoping some of this rings any bells to any of you as I'm really about to give up...

I don't know the proper terms, I do not have a manual in front of me but I do have a 2QM15. If I followed you correctly, yes moving the fuel control rack forward will decrease RPM. On the fuel control rack there should be be holes on either side of where it pivots. On mine there is a return spring on the "inboard" side and my control cable is attached to the other "outboard" side. If this were reversed I believe what you are describing would occurr. Hopefully you were able to follow me...

Good luck.

The nemesis · #5 (**permalink**) 02-17-2012

Forward on the engine is the idle position.
Check your cable movement when at min and max trottle.
When at minimum cable generally extends, which would put you at idle.
good luck!

gqmf · #6 (**permalink**) 02-17-2012

Thanks; little luck here as yet... when she starts; still runaway-effect... it is very strange; sometimes she'll start first try and sometimes it just takes many, many tries... so pulled the exhaust manifold off and the mixing elbow; all clear; however now she's been spitting both exhaust smoke and oil out of the air intake... I fear the worst here though still not sure what part of the engine to fear for... I just don't get it... also checked the governor; all weights and sleeve move smoothly (didn't check clearance though), both levers turn smoothly...