Merc 2.5L 260

**Markus** · 07-26-2016, 03:59 AM

Originally Posted by crusader83

What fuel pressure regulator can I use? My fuel pressure is low at 30psi at idle. The pump is good and I have determined that the regulator is bad.

Fuel pressure should be lower at idle. It is designed that way.

**Markus** · 07-26-2016, 04:01 AM

By trying to fix what is not broken and messing around with the cooling system and the fuel system, you risk creating real damage...

**crusader83** · 07-26-2016, 06:24 PM

I haven't messed around with anything cooling or fuel related. But with the fuel pump on it only makes 30psi. With the engine on at idle it made 32psi. At 5000rpm it was at 34psi. From what Ive read it needs to be higher. That's why I'm asking. I also had no water psi at idle on the gauge so I asked how the cooling system should be. I'm trying to learn these things. But I ask before I make any changes.

**patchesII** · 07-26-2016, 08:28 PM

You might want to check your fuel pressure gauge. If it is correct I would check for any obstructions such as a clogged filter. If all that is ok change the regulator. You should see 37-38 at idle and 39 while running, depending which ecu you're running. 0-5 psi of water pressure at idle is pretty normal

**crusader83** · 07-27-2016, 12:13 AM

Originally Posted by patchesII

You might want to check your fuel pressure gauge. If it is correct I would check for any obstructions such as a clogged filter. If all that is ok change the regulator. You should see 37-38 at idle and 39 while running, depending which ecu you're running. 0-5 psi of water pressure at idle is pretty normal

I'm going to put a gauge right at the fuel pump. Ill check it after that. The fuel gauge is a brand new Gaffrig mechanical. But you never know.

**tlwjkw** · 07-27-2016, 05:10 AM

what Eric says... that 30 lbs sucks.. will get ya in trouble.. what kinda a regulator is it?.. stock gold?.. aftermarket?

**crusader83** · 07-27-2016, 07:58 AM

Originally Posted by tlwjkw

what Eric says... that 30 lbs sucks.. will get ya in trouble.. what kinda a regulator is it?.. stock gold?.. aftermarket?

Yeah. It's the stock gold Bocsh one. I'm going to mount a fuel psi gauge on the outlet side of the fuel pump so I know for sure where the psi is at.

**tlwjkw** · 07-27-2016, 08:44 AM

don't think that will get ya what your lookin' for unless ya jus checkin' tha pump for pressure but ta be truthful, i've never put a gauge there... always "assumed" if had right pressure where its suppose ta be then tha pump was fine...only pumps i've had either put out or shut up.. never in between...

needs ta be after tha regulator... ideal place is little "jumper" between fuel rail and return... gl with it.

problem persist.. keep plunkin' at eric.. knows way more 'bout this junk than i....

your welcome eric!

**crusader83** · 07-27-2016, 08:59 AM

Originally Posted by tlwjkw

don't think that will get ya what your lookin' for unless ya jus checkin' tha pump for pressure but ta be truthful, i've never put a gauge there... always "assumed" if had right pressure where its suppose ta be then tha pump was fine...only pumps i've had either put out or shut up.. never in between...

needs ta be after tha regulator... ideal place is little "jumper" between fuel rail and return... gl with it.

problem persist.. keep plunkin' at eric.. knows way more 'bout this junk than i....

your welcome eric!

It has a line coming from after the regulator to the dash gauge.

**tlwjkw** · 07-27-2016, 09:23 AM

perfect.... always used "real" stuff to tha dash myself.. less faith in 'lectric and more faith in stainless braided hose showin' real thing...... gotta lotta abuse from several folks 'bout that.. said it would 'ventually burn tha boat down.. still waitin'

**crusader83** · 07-27-2016, 09:26 AM

Originally Posted by tlwjkw

perfect.... always used "real" stuff to tha dash myself.. less faith in 'lectric and more faith in stainless braided hose showin' real thing...... gotta lotta abuse from several folks 'bout that.. said it would 'ventually burn tha boat down.. still waitin'

im using efi fuel line in 3/8 up to a mechanical Gaffrig gauge. But it's only showing 30psi not running and 32 psi at idle. That's why I want to put a gauge permanently on the engine.