K-click / Low flying article

[elie boone]

I just red the article in Low Flying about the MFRU, i gues the main relay has a higher Amp rating, so it will have better quality contacts.

Could it be that simple to just place the pin 8/5 to 8/8 OR 8/3 ?

 

Edited to say you will need a starter button to do this, then u just earth pin 6/3 with the button.

 

Edited by - elie boone on 16 Jul 2013 11:39:56

[SUPERLIGHT91]

On my '99 1.8k that has the click of death like clockwork when it warms up:

 

I have now done the following to no avail.:

- fitted a double reflective ali plate around the starter to shield a bit from heat from the manifold

- fitted new, high aH Banner battery for more current at startup

- checked all connections for corrosion and tighness

- followed the master relay conversion, upgraded the 12v cable to the starter

 

All of the above has made no difference, its still clicks like clockwork when the car heats up.

- The last thing for me to do this weekend is bypass the push button start and go back to key-turn ignition to remove another component from the equation

- After that its a new Brice starter (which is the most expensive thing to try as a last resort out of sheer desperation).

 

If anyone can suggest anything else to try before I go for the new starter next week - I welcome any/all suggestions (and don't say, sell it and buy and a Duratec, I've heard that one before, and actually do run Duratec car too, but it would be nice to sort the trusty old K-series).

 

Thanks

[charlie_pank]

 

It's a cumulative problem of resistance. So there's rarely 1 permanent source of this problem or a 1 stop fix. Have you thought about how to diagnose which of the many factors may be to blame? eg. When you get the dreaded 'click' can you get the starter to spin by shorting the terminals? - what does this tell you? Where does the 'click' come from is it from the relay or the solenoid? - what does this tell you? etc...

 

- Replace ALL the cabling to the starter

- Rebuild (and clean) the starter

 

 

 

NB The push button feeds the relay. If you hear the relay or the solenoid clicking, then the button is doing its job, there's no point in replacing it.

[SUPERLIGHT91]

That's my thoughts exactly and as I've tried everything else its either the starter itself or a cooling issue (as the car does seem to get very hot), my theory is I need to check for air blocks and water pump effectiveness, as one idea is that several components are overheating/expanding, and when you stop and try to re-start the starter jams without enough oomph to turn over the expanded hot pistons in their liners. - just another theory though.

[SLR No.77]

Quoting SUPERLIGHT91: 

On my '99 1.8k that has the click of death like clockwork when it warms up:

 

I have now done the following to no avail.:

- fitted a double reflective ali plate around the starter to shield a bit from heat from the manifold

- fitted new, high aH Banner battery for more current at startup

- checked all connections for corrosion and tighness

- followed the master relay conversion, upgraded the 12v cable to the starter

 

All of the above has made no difference, its still clicks like clockwork when the car heats up.

- The last thing for me to do this weekend is bypass the push button start and go back to key-turn ignition to remove another component from the equation

- After that its a new Brice starter (which is the most expensive thing to try as a last resort out of sheer desperation).

 

If anyone can suggest anything else to try before I go for the new starter next week - I welcome any/all suggestions (and don't say, sell it and buy and a Duratec, I've heard that one before, and actually do run Duratec car too, but it would be nice to sort the trusty old K-series).

 

Thanks

Non of the above will solve the click (although I'm not sure what you mean by "master relay"), it's the relay in the MFRU that you need to bypass. I've done the mod to both my current car and the previous one and solved the problem completely in both cases. On my current car, when I sorted out the previously botched loom I also included new wires fed back to the fuse/relay panel where I've fitted an additional relay especially for the job, taking the MFRU relay out of circuit. This has involved longer wire runs which have often been thought to be the problem but it works perfectly

 

Stu.

[SUPERLIGHT91]

Yes, by master relay I meant the MFRU mentioned in the low flying article.

 

Although technically, as I left the car for testing, the MRFU is still in-line and I just have a single 30A relay with waterproof 30A fuse, and some nice hefty 12v cable feeding the smaller of the two wires to the starter and that obviously didn't work for me, so its not that.

 

Edited by - SUPERLIGHT91 on 25 Jul 2013 16:18:39

[SLR No.77]

Quoting SUPERLIGHT91: 

Although technically, as I left the car for testing, the MRFU is still in-line

If the MFRU relay is still in-line and you still have a problem you need to bypass it.

 

Stu.

[SUPERLIGHT91]

I will continue with the complete Master Relay unit bypass this weekend as a final test before starting to look at starter itself. Thanks

[Jonathan Kay]

You've checked connections but only replaced one cable. A cables that looks OK but has high resistance could still be the cause, as suggested above.

 

What's the voltage at the starter terminal before and during starting?

 

Jonathan

[Slipper man]

Take it to Redline in Caterham. They put on a relay which has permanently cured the problem. I am on my 5th starter now and was about to replace the current, when Redline suggested the cure. It has worked and I have probably wasted the other 4 starters! Whenever the car got hot it would fail to start. Today it was with the two Steves being remapped and got REALLY hot. Still started on the button every time!

[SUPERLIGHT91]

Johnathan - I will check output voltage at starter at w/e that is a good idea

 

Replaced more than one cable for the current test:

- starter B cable to relay

- cable from relay to battery, via new in line fuse

- cable from relay to earth

- and the exiting starter B cable to the relay

 

Slipper Man - do you know which relay Redline swapped out - did they do away with the OEM Rover multi-function relay box completely do you know?

[charlie_pank]

I have literally lost count of the number of times I have explained that the starter click symptoms are caused by one or more of a number of issues. Because there are so many things that can contribute or cause it, even after you fix it, it may recur because something else pushes the system's resistance over the limit. Also just because one thing fixes it in one car doesn't mean it'll fix yours.

[SUPERLIGHT91]

Good point Charlie - I will continue working through and bypass the complete MFRU next.

[SUPERLIGHT91]

Right, today I stripped the MFRU and had all the connections prep'ed out ready to fit the 2nd relay only to find ALL OF THE COLOUR CODING OF THE WIRES IS DIFFERENT ON MY CAR TO THE K-CLICK ARTICLE so I have had to put it all back as it was, grr!

 

Summary Q: Has anyone a wiring diagram to bypass the earlier K-series MFRU?

 

KClick Article shows the following colours, compared to my EU2 '99 car (in brackets)

6/1 blk/ppl (blk/ppl)

6/2 wht (gr/pnk)

6/3 wh/pnk (wh / pnk

6/4 blk (blk/wht)

6/5 no cable (blk/grn)

6/6 wht/red (wh/red)

8/1 brn (no cable)

8/2 no cable (brn/bl 1)

8/3 no cable (brn/pnk 1)

8/4 yel/grn (yel/grn)

8/5 brn/red(brn/red)

8/6 brn (brn/blu 2)

8/7 brn (brn/blu 3)

8/8 no cable (brn/pink 2)

 

 

[Two Wings]

Hi Superlight91, I have the K-click problem as well & it really reared its ugly head after spending the whole of June in France, mainly touring.

I too tried the LF article this week, even purchasing 2 new 30amp relays to carry out this conversion & like you found the wiring colours not only different but with some extra wires!

I would also be very interested if anyone has a solution with our wiring lay-out.

 

Ron 'Two Wings'

[Slipper man]

SL91: they left the existing box in place and just added the new relay. very neat job though and didn't cost much either.

[Mick Day]

Have a look here for the earlier MRFU wiring. Works on my 1994 vintage car

 

AFAIAA in the earlier wiring the injectors & the lambda sensor are powered by the main & OS relays respectively.

 

Not having had K series starting problems for 11 years I've just had to replace my starter motor. Now starts hot & cold. As Charlie says it's not one solution all the time but consideration must be given to the whole system.

 

And if you do employ the starter relay mod remember that the new relay may exhibit arcing & corroded contacts after a while. replace mine every spring.

[Bricol]

Being lazy I did it the easy way. Used a spare terminal that became live on the ign switch in "start" position and used that to fire a new relay under the dash. I took a new fused live direct to the new relay, and a new wire out to the starter solenoid. Disconnected the original wire to the solenoid and tied it up,, insulated.

 

Checked the original main power cables to the starter, they seemed fine.

 

I've not even thought about the k click in five years or more. It just starts. Hot, cold, left for 5mins or 5mths (okay,needed the banner charging for that one )

 

Bri

 

 

[revilla]

Hello everyone, I thought I really I ought to come in and say something here as it was my article in Low Flying ...

 

First of all I can only agree with Charlie Pank that there are a whole number of possible causes for this problem, with the final result being the cumulative effective of higher resistances (possibly both electrical and mechanical) in the system. There is no one-size-fits-all solution, however the starter relay in the MFRU has been consistently identified as one of the the major contributors and for many people experience has shown that replacing this significantly improves the situation.

 

My article was really aimed at saying that if you are going to bypass the MFRU relay, there is what I consider to be a neater way to do it. I was not trying to claim that my method would be any more effective in curing the click than the traditional bolt-on relay, as electrically they are pretty much identical, except in that the less wires are joined together (particularly using Skotch Lock or similar connectors) the more reliable it is likely to be.

 

It was slightly unfortunate that the editor of the magazine chose to abbreviate the original title of my article, which made it clear that I was presenting a "Neater Solution" to the existing modification, to simply read "K-Click" in large font, which makes it sound as though I was presenting a final and definitive solution, which was not my intention. As a relative newcomer I was not trying to present myself as any kind of expert. I have a very great deal of respect for the accumulated experience and wisdom to be found on here and would not wish to be seen as criticising anyone or treading on anyone's toes. I did however feel that having applied a little analysis to the most commonly tried solution I had found a neater way to implement it and wanted to share that with the wider community, hopefully to pay back a little of the debt I owe for all the help I have found on here.

 

Secondly I did include a big disclaimer that people should carefully check that their wiring was the same as mine before proceeding. I checked my wiring against the wiring diagrams in the Caterham Seven Assembly Guide - All Models (11.3MB) and found them to be consistent, so I was at least confident that I had "standard" wiring but I could not be sure that every other car would be wired like mine. It does seems that some earlier cars were wired differently. If, as it sounds, in earlier cars some of the other relays in the MFRU were actually used, although it would still be possible to replace the MFRU with up to four separate relays, this is starting to sound like a more combersome and complex solution and I would probably stick with an additional external relay for simplicity in these cases. For those cars which are wired as per the wiring diagram, it just worked out as a very neat solution with no need to join wires at any point.

 

My apologies to anyone who has been out an bought parts only to find that the modification is not appropriate to their car. For anyone who stumbles across this thread in the future all I can do is reiterate the warning I put in the article:

 

Warning: This modification was performed on my car, a 2003 Roadsport SV VVC 160. The wiring on my car was consistent with the wiring diagrams provided in the Caterham K-Series Build Manual, however I cannot be 100% sure that the wiring on every other K-Series car will be identical. I have therefore included in the instructions below a diagram of the existing connections to the MFRU in my car and IF YOUR MFRU WIRING DOES NOT CORRESPOND TO THAT SHOWN IN THE DIAGRAM, DO NOT CONTINUE as the modification may not be applicable to your car.

[SUPERLIGHT91]

Thanks MickDay for the earlier wiring diagram to work through.

 

Thanks also to Revilla for the original article, and taking time to share his SV '03 solution with us and share the debate.

 

Does anyone know where best to simply get a new MFRU for earlier cars? - I have my doubts about the condition of mine for the following reasons:

- it had been opened before

- it had "Rat Race" etched in the underside (so has probably been serviced or mod'd by the previous owner via this well known 7 tuner and purveyor of parts)

- 2 of the 4 solenoid/relay contacts were pretty pitted

 

I have cleaned pitting as well as possible carefully with some emery paper, but a spare would be handy, and I have stuck with the starter-bypass relay only for now and the MFRU still in line for now while I investigate other possible sources of resistance and starter condition on this 1999 K-car.

 

Edited by - SUPERLIGHT91 on 28 Jul 2013 09:50:04

 

Edited by - SUPERLIGHT91 on 28 Jul 2013 09:50:51

[Mick Day]

Revilla: Your Low-Flying article was excellent & included ALL the necessary information & warnings required.

 

Superlight91: AFAIK these MFRU's are in short supply. Caterham are out of stock. Ebay could be your friend? As mine was 19 years old I decided to remove it completely & replace with individual relays. Procrastination stopped me doing this 11 years ago as once the starter relay was bypassed everything else worked. It was only when I was getting intermittent fuel problems that I decided to junk the MFRU (I don't have a lambda sensor).

 

At some point in the future I'd like to completely replace the engine loom, fuse, relay box. However whilst it still works.....................

[John Vine]

Quoting Mick Day: 

Revilla: Your Low-Flying article was excellent & included ALL the necessary information & warnings required.

+1 *thumbup*. In fact, the article prompted my son-in-law (owner of my old SS-R) to investigate and fix his click.

 

JV

[CliffC]

I have symptoms of the K click so after having a look at the low flying article I notice I have all the connections in Fig3 except I also have a brown and blue cable in 8/8. On the diagram it suggest this should have nothing connected.

 

Does anyone know what this is used for?

 

Car is a 2006 1.8 xpower 140. MFRU model YWB 100970-1

 

Thanks

Cliff

[revilla]

On Caterham's "EU3 1.6 and 1.8 K-Series engine loom wiring diagram, all variants" there is no Brown/Blue connection shown to the MFRU. I presume from the year of yours that it is EU3? According to the "BS-AU7a 1983 Colour Code for Vehicle Wiring", Brown/Blue is usually used for "Control box (compensated voltage control only) to ignition switch and lighting switch (feed)." and Blue/Brown is usually used for "Headlamp relay to headlamp fuse.". The only Brown/Blue wire I can find on the wiring diagram is from the ignition switch to the lighting switches, which sounds very unlikely to have been routed through the MFRU on yours, so I don't think this is giving us much of clue and Caterham must have used this colour wire for their own purposes.

 

According to the diagrams in the Haynes manual, connection 8/8 is a switched output from the Master Relay used to power the injectors. Connections 8/8 and 8/3 are interchangeable, and to be honest could be used to switch anything high powered from ECU pin 4.

 

All I can say is that i) I don't have a wiring diagram that covers your car so can't be sure what the connection is for (although hopefully someone else will be along in due course to enlighten us) and ii) it appears that the Main Relay is in play in your car, which to be honest means that my modification would need to be heavily revised, would need at least 3 relays and would probably involve splicing multiple wires together again.

 

All in all, for your particular car I would assume that my modification is not applicable and I would advise you to stick with the "traditional" approach of adding in an extra relay (in addition to the MFRU) as is documented in various other threads on here. Make sure you use the modification that takes the existing MFRU starter relay right out of the circuit, rather than the one which still uses it to drive the extra relay.

[CliffC]

Revilla

Thanks for the explanation . I know it has been done before but does anyone have the link whereby the modification takes the existing MFRU starter relay right out of the circuit please?

Thank you

Cliff