6 replies to this topic

[archbonkers]

The haynes manual I've got for this car just starts off by banging on about taking off the UIM, and little else.

 

Is it really under the inlet manifold? Or are they just telling you to take it off so it's easier to access (like they do with changing the spark plugs when in reality with the right tools there's absolutely no need to take the UIM off to do them). I've read some conflicting opinions online about where it actually is but most opinions I've found don't say it's under the manifold.

 

Cheers.

[raynkar]

I have no knowledge of removing the UIM to change the spark plugs on the 2.5, I know the Haynes manual says to do it for the 3.0 V6, but then you need to do it for the 3.0. 

 

Have you looked in the book for the Mk2 mondies as they had the same V6 engine you have.

[archbonkers]

I haven't looked at the mk2 haynes manual if that's what you mean. Although the thought gave me an idea to look for an actual ford workshop manual for this car. Couldn't find any specific one in pdf that wasn't in russian or spanish annoyingly but I did find something called ford TIS 2004, having a look in that I found a diagram for the 2001 v6 2.5l with the regulator location pointing to where the air intake is on the UIM, so presumably it's either directly under it or somewhere very close by it.

 

It may be accessible without taking the UIM off, but I can't see it from above. I'll try and get a torch and some eyes under there, maybe in the form of my phone camera, and see if I can spy it, but at least now I kind of know exactly where to look.

[ancienttyres]

did you ever find the regulator in the end? Having same issue locating the damn thing on mine. Lifted manifold up a bit (I just undid the bolts so I could - didn't take anything else off it as I didn't want to completely remove it) but I couldn't see the regulator under there where it's supposed to be, but granted I didn't quite get enough lift on the manifold to get a very good view. I will have to take the bast**rd off if I want to get a proper look and I just don't want to do that if it turns out there isn't a fuel regulator under there.

 

I found posts on here from ages ago where someone claims the fuel pump is responsible for regulating the pressure which makes me less inclined to take the inlet manifold off.

 

Would love it if someone in the know could shed some light on this!

[archbonkers]

did you ever find the regulator in the end? Having same issue locating the damn thing on mine. Lifted manifold up a bit (I just undid the bolts so I could - didn't take anything else off it as I didn't want to completely remove it) but I couldn't see the regulator under there where it's supposed to be, but granted I didn't quite get enough lift on the manifold to get a very good view. I will have to take the bast**rd off if I want to get a proper look and I just don't want to do that if it turns out there isn't a fuel regulator under there.

 

I found posts on here from ages ago where someone claims the fuel pump is responsible for regulating the pressure which makes me less inclined to take the inlet manifold off.

 

Would love it if someone in the know could shed some light on this!

No, I didn't figure this out. The haynes manual for my car year, 2000 - 2002 (green book), states regulator is under the manifold on the fuel rail. They're wrong. The Ford TIS 2004 just makes a somewhat vague mention of it being under the manifold by pointing to it on a diagram. That was also wrong. On the mk2 25l v6, which is almost identical to the mk3 engine, the regulator is absolutely under the manifold where everyone says it is, but it appears the mk3 2.5l v6 had a minor alteration at some point early on and they either moved the regulator somewhere else or just replaced it with some other type of system. Unfortunately, I coudn't find f**k all about it anywhere. Not on the web, not on this forum or any other forum.

 

I was going to do what ryankar suggested, except rather than look at the mk2 book, try looking at the haynes 2003 - 2007 (facelift models, red book) manual instead since it made more sense that they might have actually updated their methods for the newer facelift engines. However I actually ended up finding out my problem was the fuel pump so I didn't go any further.

[Communist]

I believe they did this with the 4cyl petrol as well. Mine does not have the fuel pressure regulator on the fuel rail, but I know the earlier cars did have some kind of damper there. They probably stopped around the time of the facelift. The haynes manual for the facelift also says the v6 fpr is under the manifold, but a lot of the facelift manual is copied from the prefacelift one, and so is wrong in several areas.

[ancienttyres]

Can confirm. Haynes manual is wrong. I've had the manifold off completely the other day; fuel rail out n'all while checking injectors and there definitely isn't a fuel pressure regulator on the rail where haynes claims it is. They've just copied the mk2 duratec spec! Lazy bastards.

 

Anyway from what I've read up on all this it turns out the mk3 has a "returnless" fuel system. Basically the regulator is in the pump, it seems like it can be removed but it isn't adjustable or serviceable. Pump does have two lines though from what I can tell, a red return and a white feed, I think this is because the filter is outside the tank (it seems like usually returnless systems have the filter actually in the tank with the pump and the regulator so no need for a return at all outside of the pump).

 

Anyway I'm guessing the feed goes to the filter and then presumably it splits off into two lines afterwards, with one line going back to the pump as a return (and into the regulator inside the pump assembly) and the other line goes off to the fuel rail on the engine. The ECU controls pressure entirely by controlling the pump operation. If at any point the pressure gets too high the regulator lets fuel bleed back into the tank. I could be wrong about the return, I've only gone by pics I've found online and they all seem to show the pump having a return.

 

Oh well. At least this solves that little mystery (well, it was a mystery to me at least).