MFU - help needed.

[MJS]

I have been enjoying the build of my Superlight so far but was totally stumped today when I was connecting engine loom to chassis loom. ECU was simplicity itself to fit (although I seem to be 1 spacer short), but the MFU (multi function unit) is a different story. Firstly it says the unit should be fitted underneath the ECU - not possible, no room. Then I noticed there were no mating connectors on either the engine or chassis loom. What exactly does this unit do and am I in trouble because of the lack of connectors? Engine is a 140 BHP supersport if that should make any difference (can't see that it would).

 

Cheers,

 

Matt.

[robmar]

MJS is this a new rover EU3 engine (wasted spark, coils on top of spark plugs, no dizzy etc)

 

if so the wiring info in the manaual is out of date, if anything like mine and I only have 1 box with 2 multi connectors, and I do not think that is the MFU you describe (this is the ECU)

 

I wouldn't worry too much, but check with caterham

 

rob

[Bob Corb]

On the eu3 engine you have to have extra wires put into the std rover engine harness to feed the mfu, this (black placcy thing with to large square sockets) sits on top of the ecu (aluminium cheese wedge) A caterham supplied loom should plug straight in. It should be obvious which plugs go where. For info the mfu houses 2 relays, one for the fuel pump and the other for the lambda sensor. If there are no large plugs coming out of the engine loom near the ecu then it looks like the loom hasn't been swapped by Caterham for their modified version although if your engine loom has the smaller ecu plug then it must have been modified. I'm confused now, please let us know when you sort it. If you need to see an eu3 engine as fitted let me know I'll bring my car to work tomorrow and I could photograph bits for you

 

Bob

[MJS]

Just to clarify:

 

ECU (ali, wedge shaped unit) fits OK and has two multi way connectors (one larger than the other) which both fit OK apart from the smaller of the two which seems a little reluctant to mate up, but I'm sure with a bit of *persuasion*...

 

Engine is a brand new K series. Can't say for definate if it is an EU3 (how do you tell), but it does have twin coils on top of the plugs with wasted spark ignition - no dizzy.

 

There is another box which sits on top of the ECU which I believe is the engine immobiliser unit (no mention of this in the manual), this plugs in OK.

 

I'm all for leaving the MFU off but I will check with Caterham just to make sure, as I'm sure the harness would have been made correctly. I'll post the outcome as a reply to this posting.

 

Bob - yes photo's of the engine bay would be helpful particularly the area in question - thanks. You could mail them to me at: matt@netality.com

 

Thanks for your help.

 

Matt.

[masha]

To MJS

 

Interesting another MJS with a Superlight. I am Matthew James Stears and I've had my '97 Superlight 6 weeks now. I usually go by the alias of Masha. Good luck with your project

 

from

MJS

[Peter Carmichael]

The thing you are describing as the MFU is not the MFU.

 

Box sitting on top of the ECU is the MFU. It sits on top with the EU3 rather than underneath with the old style.

 

Don't know what this other box you have is.

[MJS]

Thanks Peter, hopefully that clears that one up. There aren't any connectors to suit the other unit so I'm just going to forget it. If it starts and runs OK then there'll be no nead to worry about it.

 

One other thing that has been worrying me is the 'fuel trap'. I have the item in my kit along with the bracket, but in the manual it implies it is already fitted (as it did with the ECU) to the bulkhead next to the inertia switch. However, there is no provision made in the bulkhead for the fitment of this, and the feed from the throttle body is as good as blanked off, and there is no provision on the ECU to accept the outlet. Is this another part that has been superceded and is now surplus to requirements?

 

Masha - small world eh? thumbsup.gif I'm Matthew James as well - spooky! Apart from the above, the project is going well - I'd recommend it to anyone.

 

Cheers,

 

Matt.

[Bob Corb]

The box on top of the ecu is the MFU, the other black box with 2 rectangle multi way connectors is the immobiliser. It should have the digits 5AS written on part of the label. This box sits up in the drivers footwell above your right knee, my car had 2 M5 bolts and nylocs jangling in the holes waiting to fix it in. There will only be 1 rectangular plug which will only go in one socket. The other socket connects to the electric windows/central locking on a Rover (I hope you dont have either of those fitted).

 

Sorry I didn't get the photos to you, I was running around a lot today. If you have any queries which you still aren't sure about give me a ring, I'll mail you my number.

 

Bob

[MJS]

OK - sorted. I rang Caterham today and they confirmed this to me. I was wondering what the other connector in the footwell was.

 

Got my engine started tonight but only after a lot of head scratching because it would crank but not fire up. A quick test revealed no 12V at the pump connector in the right rear corner of the car. Luckily a mate came round and asked if we'd reset the inertia switch. I said I hadn't tried because I didn't know how you did it. He promptly pushed the rubber cover on top, switched ignition on, and hey presto the fuel pump sparang to life! Engine then started, but it soon became apparent that the brand new supplied header tank is faulty and is leaking around the seam. I can feel a warranty claim coming on.

 

Anyway, thanks for all your help guys - hope to meet up with some or all of you at some Caterham meets in the future.

 

Cheers,

 

Matt.