I have just fitted a mk1 focus rs throttle body to my mk1 2.0 zetec focus to try and improve throttle response and power, without paying 200-300 for c bbk or cfm throttle body.
It fits straight onto the inlet as they share the same inlet, I used the throttle position sensor connector from an rs, clipped off and replaced my standard connector with it, as they both have 3 wires (Brown, white, yellow), connected it all up, but its spluttering and cutting out?
I can't see any reason why this shouldn't work, but its not?
Any idea or info would be great, as I can't find any threads with anyone doing this mod (but could be a good reason why)

 

Are the plugs wired the same on the tps?

 

99% sure they are, but I was wondering the same thing, the hardware can't be the problem so it must be the tps in some way...but how? I did take it off to try and fit my standard one, but it only fits one way!

 

Did you set the tps up im sure you bolt it up loose turn in direction of twist on butterfly ,hear/feel it click then back it off and tighten up.
The last time i had to do it was on my 205gtivan fifteen years ago do forgive me gor any duff info.
Can you get your hands on both wiring schematics to chech on wiring?

 

better off either buying a ported std 2.0 t/b or buying a second hand cfm t/b (i picked one up last week for Ł90)

 

Don't believe they need setting up as they are none adjustable, I have the wiring diagram for my 2.0 but not the rs, can't find one as of yet, but if I can check the wiring is correct, they if must be something else, someone suggested the maf sensor, but I don't see how that can be effecting it?

And I've been digging about for c cfm one for ages but with no luck! Where's a good place to look besides the obvious like eBay and here?

 

what resistances do both sensors have, and from what points do voltages start and stop?

wiring problem i bet, like reversed wires.

 

Think it will have to be set up as in set the neutral position
My understanding on how they work is that there is a base map for tickover when the throttle is shut.
when you open the throttle it turns on the tps and the more you open the buttterfly the more it increases the fuel/ign through the ecu map.

 

Couldn't tell you tbh mate, I may try and make my original tps fit....as you just pointed out it may be a difference in the tps that it doesn't like, I'm sure the wiring is correct as they match colour for colour, so its most likely different inside the tps.

 

How do you set it up then? I was under the impression they was none adjustable at all.

 

Agree with this - I did have a look on ETIS but they don't seem to have the RS info on there any more.

No adjustment on them - TPS sensors used to be adjustable years ago.

 

TPS/MAF sensor are your main load inputs to the ECU, if one fails the engine will still run well with the other disconnected as they substitute each other.

So, if MAF fails and car runs shit, disconnect the MAF and it should run well on TPS input, and vice versa.

As it runs crap with new TPS it must be either fooked, or wired incorrectly.

 

That's the 1st thing I tried, disconnected the maf sensor, no difference...but could I do the same with the tps? Unplug it and see if it runs?

If I could get hold of a wiring diagram for a rs, I could compare it to the one I have of my 2.0 and know 100% if its wired correctly.

Can you see my thinking though, people do a bigger throttle body upgrade all the time, and seen as the only difference on this is the tps, it must be something to do with that?

 

If it runs well with TPS disconnected, and MAF connected, it proves that TPS is faulty.

It's annoying that they seem to have taken the RS specific info off ETIS, or I could have checked it out for you.

Might be worth looking for an old TIS CD which may have the Focus RS info on it.

 

http://www.fordpartsuk.com/shop/ford...1403_c_359.htm

This proves that RS has it's own TPS as it fits most other Focus.

 

If car ran ok before you changed the throttle bodie then it has to be something you've done
ie. Fitted a duff tps
Are the rs and focus the same shape?

 

Yeah mk1 focus, the rs throttle body is surprising similar to an escort throttle body though, as they share the same tps. With the tps disconnected it runs as bad if not worse but I've adjusted the throttle idle position using the adjustable pin thing, now it starts and runs for 5-10 seconds, then cuts out.
I had an issue at 1st on my standard tb as I'm running heavy cams, but I haven't got the induction pipe properly on yet as I don't have the correct size pipe, but could it be its drowning in air after it starts to idle without the pipe correctly on? If that makes sense..

 

The RS doesn't share the same tps as the other mk1 focus, but what if I tried my standard tps to see if it fits?...and more to the point, runs better?

 

FFOC
Focusowners.com

There your best bet.

 

Hey Guys, so the TPS for the Mk1 RS is the same position sensor as the escort zx2 here in the states. The problem with it is the the computer reads the information in reverse if you try installing it on your Mk1 focus. It will read 80% throttle position instead of 16.5% and as you put your foot down the percentage goes down. The only way to counter act this is by swapping the TPS sensor with a mustang and Mk1 focus sensor that is similar that allows the computer to read position correctly. I'm still searching for the right sensor that will mate up to it properly. You can connect the wires right all day long but it will not change what the sensor tells the computer.