Where the heck is the fuel regulator
 

and test valve on a 1999 502 mag mpi????? I'm installing an adjustable one.

The regulator is down on your fuel pump,
( cool fuel) take the cover off, there's a vacuum
line hooked to it.
hope this helps.
jt

Have same engine and just did the same mods..thanks to the input from the folks here I can tell you what it was like.
Like jt says regulator is in the cool fuel box under port side of engine.Access to ours was tricky so we removed ALL the lines and box and pulled it out from under the front of the engine.I dont think (in retrospect) that you would really want to do it on the engine because what happened to me is the new regulator does'nt fit completely in the box so the box has to be modified.When we went to re-install cover plate on box one of the nuts incased in the plastic broke free so we had to again remove whole assy. and find another new box... and lastly there is a very important O ring that seals the pump to the cool fuel assembly that if not installed correctly will leak fuel when the pump is pressurised.
The pressure test valve is under the front of the air plenum,it is a schrader valve and your original pressure should be 32=35psi..with new s/s exh manifolds and gert big air breather our is now 43psi...We used a merc injector test tool that performs a number of checks on the MPI engines to measure and re-set the pressure.. it just plugs into the test outlet like a bicycle pump onto the valve !

This is re-cycled information also based on practical experience.. hope it helps.

Steve

do you need this merc tool to do the job right ?

What tool

madbouyz STATES>> We used a merc injector test tool that performs a number of checks on the MPI engines to measure and re-set the pressure.. it just plugs into the test outlet like a bicycle pump onto the valve !


Confused here now, I thought I just replaced regulator n tuned pressure with gauge hooked up?

did you put it on yet Liquid? what brand of reg is it ?

not yet, I'm still not real clear, it must be hard to find, it is a vortech

Here you go Liquid,

This is from BAM's site.

Part #15 is the regulator.

Ron

Here's a link to that page.

http://www.mercruiserparts.com/Show_...ND+FUEL+COOLER

Ron

Thanks Rj that makes it easier. That Merc tool madbouyz is talking about above, Do you need that to do the job ? I thought all I need was the regulator and a gauge to set the pressure?

CAP...
Sorry for any confusion.The tool I spoke of is a Merc shop tool.It really is nothing more than a large water filled pressure gauge.My mechanic who assisted has used this before in conjunction with the EFI test computer (that plugs into the harness) to check for injector leakdown and duration when we were trying to figure out the dirty transom problem...that was before I had the input from everyone here :eureka:
Unlike probably a lot of folks here on the board I don't have a dash mounted fuel press. gauge.That's why I made mention of this Merc tool.
If I can add a bit more,I was assured that you only need to follow the (limited)instructions on the fuel regulator inst sheet ..ours is a vortech too..and it is no problem .... YEAH RIGHT :(
like every other boat job it takes three times longer than you could imagine.Also find a tool (and it will be a small one) to adjust the nipple on the regulator BEFORE you install everything again.If I remember correctly it is not an SAE size and you could end up looking for a while for something that works in the possibly limited space to work in that you might have.
Let me know how it goes ...
Steve