K Series Starter - The Cure??

[Paul Richards.]

I have a 1.8 K series Roadsport. It was new 2.5 years ago and after 6 months began giving problems with the starter when the engine was hot. A couple of new starter motors under warranty gave temporary improvement and moved me out of warranty. Since then it has gone progressively worse and was impossible when a battery cut off switch was fitted.

I have followed other threads and read about vibration causing problems with contacts, solenoids overheating, use of insulation, exhaust wrap etc. but none of these appear to be relevant or effective on my car. Incidentally my starter motor is the Magnetti Marelli type with solenoid underneath.

I discovered that the Caterham 21 race car suffered similar problems when undertaking endurance racing and it was put down to resistance in the wiring. I shortened the wire which activates the solenoid i.e. ran a new wire direct from the MFU to the solenoid and this appeared to bring a marginal improvement. I also discovered that when the problem occurs that if a wire is connected to the solenoid and contacted to the positive terminal of the battery that it started no problem. Of course one of the difficulties with such a problem is that it is intermittent and you can only investigate on the occasions (usually inconvenient) when the problem occurs.

Explaining the problem to a local auto electrician he advised that similar problems are encountered with some other cars, some Peugeot diesels being amongst them. The ‘cure’ is to fit a relay to operate the solenoid. The theory being that the relay is operated by the ‘normal’ solenoid wire and as the relay will work on a small flow of electricity, resistance in the wiring is no problem. On operation the relay directs power straight from the battery along a short length of wire to the solenoid.

Solenoid was fitted last Saturday and the acid test was last night when I went to the MAD (Merseyside & Dist.) L7OCGB. This is a journey of approx. 90 miles round trip virtually all motorway. In the past the problem has always occurred (usually at a filling station at midnight on the way home!) So far no problems!!! The ambient temperature was however fairly low (it was pouring down) and I will be keeping my fingers crossed that the cure is permanent, but it is certainly looking good. Unfortunately can’t go on the MAD Port Merion run this weekend to try it out as I’m gathering brownie points for Le Mans next year by carrying out some decorating. I will however post further results in due course. Meantime if you have a similar problem, try operating the solenoid by a temporary wire and if successful this may be the cure for you also.

Please forgive me if you clever people out there are already familiar with this cure, and also for the poor technical content of the post.

 

 

Paul R.

C7PPR

[Mike Bees]

>>I also discovered that when the problem occurs that if a wire is connected to the solenoid and contacted to the positive terminal of the battery that it started no problem.<<

 

That's not been the case with the failure(s) that I've had, it's always been the solenoid refusing to play.

 

>> The ‘cure’ is to fit a relay to operate the solenoid <<

 

I thought there already was a relay in the circuit?

 

Mike

[Paul Richards.]

Mike

1. I'm sure you are correct in that there are various problems and this is only one solution for one problem. A problem which I am sure others are suffering.

2. There probably is a relay in the circuit. Is this part of the function of the MFU? Sorry but my knowledge on electrics is not good. All I do know is that resistance comes about with heat and is also as a result of long cable lengths. The solution I think is partly because the additional? relay is situated close to the solenoid and battery. Effectively the power to activate the solenoid only has a short distance to travel from the battery when a relay is used at this point in the wiring.

I am sure this info will assist many others with a similar problem.

 

Paul R.

C7PPR

K series that starts when hot!!

[Martin Plant]

Wish this post had been here 10 days ago....

 

My new starter made only a marginal improvement. So when the problem occurred again last night I popped a wire between the battery and the solenoid and hey presto started instantly.

 

Interestingly if you look on Julian's site for the photos of his SLR build you will see that his car has a completely different solenoid and starter assembly.

 

Martin

[Mick Day]

Reactivating this thread because I've just rewired my starter solenoid so it fires direct from the battery via a relay. My starter is the geared variety marked Magneton & "failed" after 2 hours! Thinking it'd been over-cooked at the Ring I was all for buying the "race version" which is supposedly bullet proof.

 

So why should this cure the problem? The starter solenoid is activated by the ignition switch via I suppose another relay (MFU: what's this?) so the current should be adequate to "throw" the solenoid. And why should heat affect this so far away from the engine? I have a Vecta imobiliser which isolates, amongst other things, the starter circuit. I'm wondering whether the Vecta is the cause of the problem. With age & vibration (& maybe a little heat) it may be offering too high a resistance to "throw" the solenoid but enough current to activate a relay.

 

Of course this won't cure all starter problems, especially where soldiered joints have failed, but it seems to cure this one. Fingers crossed!

 

Mick

[Johnty Lyons]

Guys your all wrong [ stand by for flames] our old friend PC pointed me in the right direction, and having stripped my solenoid i know he's right!!

The problem lies with the connection that the solenoid wire goes to it's a threaded stub which you attach the solenoid wire eyelet to. it in turn is soldered to a rivit with ahole up the centre which carries the feed wire of the solenoid wiring. The problem with the solenoid is one of heat and vibration. On the output side there is a much more robust connection which carries the braided input wire to the starter itself again the solenoid wire feeds up the centre of a rivit at this location but the whole thing is much more robust and there is no mass to induce vibration. On the input side the stub is really too big and the solder connection too small to give a lasting solution and what you get is a dry joint , the action of you touching it with a wire is all it takes to activate the solenoid. Heres the proof get someone to sit in the car and turn the key to activate the solenoid then just touch the stub where the solenoid wire is connected the motor will engage and the car will start. The solution AHHHHHHH! fiddley but works. strip the solenoid elongate the feed wire from underneath the black plastic cap ending in a male spade.[ having fed the wire out through a hole in the cap where the rivit and spud were] cut the eyelet off the solenoid wire and replace with female spade, and cover push both spades together and ty wrap to solenoid body. Two problems done away with no heat sensitive exposed solder joint and no vibrating mass. It works I know Thank you PC.

 

jj

N.I. L7C AO.

Membership No.3927.

[V7 SLR]

JJ beat me to it by ah.... what are you doing BlatChatting at that hour? wink.gif

 

Worcs L7 club joint AO

Membership No.id=red> 4379id=blue>

[Nick Green]

Johnty, whether or not you are joking in your opening words, your solution is for one of the problems on the Magnetti Marelli starter with the solenoid on the top, right by the exhaust header.

 

Paul's original comments refer to the Magneton starter. Mick Day explicitly states "Magneton". This is the starter with the solenoid on the bottom.

 

F355GTS (IIRC) has also referred to differences in construction of these two starters. This is not a "one fix fits all" situation, as you seem to be implying.

 

Edited by - nick green on 10 Jul 2002 14:12:49

[Peter Carmichael]

The geared race starter has never not worked on my engine. The Magnetti Marelli starter can be modified as Johnty describes and works fine, but was marginal for a high compression engine. Don't know about the Magneton. FWIW, the solenoid failure on the MM starter was vibration related and not heat as many suppose, so I doubt that solenoid on the bottom makes much difference if the solenoid is similarly poorly designed. A fly-lead solution appropriately tywrapped seems to solve all issues.

 

I don't use any form of heat wrap because it just gets in the way and causes more problems than it solves. My headers run within 8mm of the starter motor.

 

 

 

Peterid=teal>

253 BHP K-seriesteeth.gif, gearbox and diff waiting to go inthumbsup.gifid=red>

[Paul Richards.]

Mick

I assume your starter is the one with the solenoid at the bottom and that it is now working again. Forgive me but I cannot fully explain the reason for the cure. If I understand it correctly the resistance occurs as a result of a combination of heat and the length of the wire to the solenoid. The current to activate the starter clearly travels from the battery and all around the wiring harness to the ignition switch and then back to the solenoid. When I fitted a battery isolator switch it made my problem even worse, presumably because it extended the length of wire even further. The fitting of a relay means that the current to activate the solenoid goes the short distance from the battery to the solenoid only and therefore suffers little reduction in current. The resistance presumably still exists in the ignition circuit wiring and still gets worse when it gets hot. This no longer matters however as the relay will work with very tiny amount of current. Hope this makes sense and that it is the cure for your problem. Fingers crossed also.

 

Johnty

Please put on Nomex underwear and prepare for flames. I am sure there are a number of problems and a number of different cures. As Nick says, this is for the starter (a geared one I believe) which has the solenoid on the bottom and it clearly needs ‘full power’ to activate the solenoid. I am sure that your cure is fine for your problem.

You appear to be implying that when I am attaching a temporary wire to the solenoid from the battery that I am also pressing on the contact and curing the contact problem within the solenoid. Believe me this is not the case. I have tried touching the contact on the solenoid when the key is being activated and the result is no difference. As a matter of interest I have attached a short wire (about 4 or 5 inches long) to the solenoid and cable tied it to the body of the solenoid with a male spade connector on the end. This gives me an in line spade connector joint in the wire to enable disconnection of the wire without burning my hands on the exhaust. When I have attached my temporary cable to the battery/solenoid it is at this point that I have connected it. Thus there is no pressure on the contact of the solenoid. Incidentally the connection to my solenoid is a spade connector and not a threaded stud, as you appear to have.

We clearly have different starters and different problems. As I have said from the outset. This is only one solution for one particular problem. The auto electrician who advised of the cure presumably knows a little about auto electrics and has used the same cure on a number of different vehicles.

I still need to do a few more miles and/or a track day before I can claim a total fix, but so far so good. I am also planning to reconnect the isolator switch when I have sorted out the correct wiring – see separate thread.

 

 

Paul R.

C7PPR

K series that starts when hot!!

[Mick Day]

Paul

 

You're absolutely right & I agree with everything you say, no amount of wriggling the spade connecter could induce the solenoid to operate on my Magneton starter. Incidently of Skoda origin!

As far as I know there are 3 starters doing the rounds:

 

1. Magneti Marelli with the solenoid on the top. This can be induced to work by wriggling the connecter & modifying as Peter & Johnty say.

2. Magneton geared starter with solenoid underneath. Now supplied with a neat solenoid heat shield.

3. So called race starter. Solenoid about the same size as the motor itself.

 

2 & 3 are supplied to Caterham by Brise Fabrications (01322-277622) who can also test & repair starters & alternaters.

 

Johnty

You can come out of the fume cupboard now!

 

 

Mick

 

K series which started again tonight, whether hot or cold, again & again & again & again!

 

Edited by - mick day on 10 Jul 2002 23:31:57

[Paul Richards.]

Thought I would revive this thread just to say (Johnty please note) that since I fitted my relay (almost 6 months ago) I have no starter problems, or even a hint of a problem, and this includes a track day at Anglesey last Saturday. The last time I did a track day the starter wouldn't work at all.

I'm a very happy sevener. Success!!!

😬 😬 😬 😬 😬 😬 😬 😬 😬 😬

 

Paul R.

C7PPR

K series that starts when hot!!

 

Edited by - site manager on 25 Mar 2003 21:21:17

[philwaters]

That's good Paul.

Can I ask what your symptoms were? Did it just sit there and click or did it try to turn over and then fail at the compression stroke? The later is what mine seems to do every now and again. I guess yous if the former in that the solenoid wasn't making the contact for the starter. BUt I'd be interested to know.

 

Phil Waters

You mean you can drive these?

I thought it was just there to polish 😬

[Paul Richards.]

Phil

Symptoms were the dreaded 'click'. It seems there was simply not enough electrical power to activate the solenoid. Repeated attempts also caused the ECU fuse to blow (now changed from 20 amp to 30 amp).

Your problem sounds different - as if the starter motor itself doesn't have enough power. Is your car standard or could it be high compression and or ignition timing thats the problem.

Possibly points to the starter motor itself or the main feed from the battery. If you've not already done so I would start by checking the wiring and contacts.

Could also be the battery itself that's a bit marginal.

Hope you find the cure.

 

 

Paul R.

C7PPR

K series that starts when hot!!

 

Edited by - Paul Richards. on 18 Oct 2002 15:33:12

[KenEvans]

Thank you for reviving this one Paul. My K starter problem is identical to yours and a pain in the bum so I'll be trying the relay solution.

 

However, while I managed to scrape a degree in Mech Eng many years ago, my grasp of things electrical was always severly limited because I could see nothing moving. So let me try to understand the relay connection in a little more detail.

 

Are you saying the big fat brown wire is used to operate a relay? In which case what happens to the end that currently connects to the solenoid - is it just earthed in which case is the resistance in a relay coil sufficient to stop it getting worryingly hot if you have to crank for several seconds?

 

Then it sounds like you need an equally fat wire now by-passing the original brown fat wire connected between the battery +ve and the solenoid passing via the "grunt" side of the relay.

 

Your comments would be very much appreciated to avoid smoking wiring

 

Ken

[Paul Richards.]

Ken

I have issued the following instructions to others and they have been able to follow:-

 

I fitted a 30 amp fuse - they cost about £4.00 and are available from most car accessory shops. You connect the terminals of the relay (these are shown on the relay, but are often very small) as follows:-

Common (usually shown as '30' - at least on a 30 amp relay) - This is live feed and on my car is currently connected direct to positive terminal of battery. If you are fitting to a race car (with battery isolator switch), it may be better to attach to the main supply lead of starter (which is controlled by isolator switch) and possibly incorporate an in line fuse.

85 = Signal i.e connect the original solenoid wire to this terminal (the one which comes out of the wiring loom NOT the main battery feed - as you seem to be assuming. The big (thick) brown or red wire which takes feed from battery to starter remains untouched.

86 = Negative - mine is connected to battery terminal, but I guess any good earth will do.

87 = There are normally 2 terminals on the relay (often marked 87-1 and 87-2 or 87A and 87B). One provides a closed circuit and the other an open circuit. It seems to be the 'first' terminal in the numbering sequence that is used i.e. 87A of 87A and 87B or 87-1 out of 87-1 and 87-2 etc. This terminal is connected to the solenoid.

I have used 27 amp wire i.e. reasonably thick for the live feed and for the lead from terminal 87 to the solenoid.

It has certainly been the cure for my problem. Trust this helps you and I hope it cures your problem. Drop me an e-mail if above is not clear and I'll let you have my telephone no. or I could also send a picture if that helps.

 

 

Paul R.

C7PPR

K series that starts when hot!!

 

Edited by - Paul Richards. on 18 Oct 2002 21:39:36

 

Edited by - Paul Richards. on 18 Oct 2002 21:45:51

[KenEvans]

Thank you Paul - that's very helpful. A job for next weekend.

 

Ken

[Tight fart]

my cure was much simpler, buy a spare and the problem goes away !

my starter packed up (skoda part but turns other way according to my

repair man) bought a new one from caterham as i was stuck, got the

old one repaired. and not had a problem since. but the my old blocked

radiator miraculously cleared it self on buying a new one.

 

T.F@O.F.

www.griptv.com

[anthonym]

so

 

30 to battery

86 to earth

 

85 to loom wire

87 to solenoid wire

 

where loom wire and solenoid wire were one wire that has been cut and the part that goes into the loom is to 85 and the part that continues on to the solenoid is 87

 

my two 87 's are undemarcated so I'll try one then the other.

 

hope this works! I know that touching the solenoid wire to the batter + starts the car.

 

 

Anthony

[anthonym]

rats,

 

I get a click from the relay, so presume it is closing, but nothing happens.

 

Anthony

[Paul Richards]

Anthony

Here is the article I put in Low Flying a long while ago. It seems you have the relay working, but not sending the power to the starter. Suggest you carefully re-check your conections. You have connected 30 on the relay to th positive side of the battery?

 

K Series Starter Problem – The Cure?

 

I have a 7 fitted with a 1.8 K series engine which I built new and since it was about 6 months old I had problems with starting when it was hot. This was cured by the fitting of a couple of new starter motors, but kept on returning after a while. It was at it’s worst when on a long motorway trip and the car got very hot. This was most embarrassing when filling with petrol at the services. You can picture the scene:-

Approached by the driver of a tin top and the questions/comments are usually –

 

“Is it a Pinto engine?”

“What did it used to be?”

“That looks well for an old car”

 

I’m sure you’ve all had similar experiences. I usually reply with:-

 

“It’s actually almost new and its’ fitted with a sophisticated, all aluminium, fuel injected, 16 valve, double over head cam engine etc.”

 

This seems to impress them, but oh the embarrassment of …….

 

“Before you go, could you give me a push?”

 

I’d never noticed until this time that few filling stations are built on slopes!!

 

The problem got worse, but like a lot of problems, was difficult to diagnose as it was intermittent and more often than not, my journeys start and end at home with no need to re-start en route when hot.

The symptoms were a click from under the bonnet when turning the ignition key to activate the starter motor. Repeated trying would often result in the ECU fuse (the bottom one) blowing. This was a 20 amp fuse and I replaced it with a 30 amp fuse on Caterhams recommendation. This seemed to cure the blowing of fuses, but did nothing to coax the starter motor into life when the car was hot. Eventually I managed to get my head under the bonnet when the problem was occurring and discovered that if I connected a temporary fly lead to the solenoid on the starter and touched this to the positive terminal of the battery, the engine would burst into life every time. For a couple of weeks I ran with a fly lead permanently connected to the solenoid. At least this helped cure the embarrassment of the filling station. I could now pretend I was removing the bonnet to check the oil and at the same time start the car.

 

My good friend and fellow 7 owner John happened to mention the problem at a local auto electricians and they suggested a relay be fitted as they had cured a number of other cars of various makes which had similar problems.

Nothing ventured, nothing gained and a relay was fitted straightaway. Wow!! What a difference!! The car became a joy to drive. No parking on hills and no fly leads!! From that day on the car has never failed to start.

 

I posted a topic on Blatchat and received a number of grateful e-mails from other Blatchatters who fitted a relay following my experience and also found the cure, often after buying rather expensive starter motors with no improvement. If you too have a K series engine with similar problems, then this may also help you, but I must stress that there may be other reasons!! If you are unsure, try the fly lead method out and it will tell you whether a relay is the answer to your problems also.

 

Fitting the relay

 

It will cost about £10 or £12 in bits and take about 45 or so minutes to fit.

You’ll need :-

• A 30 amp 4 pin relay – available from virtually all motor accessory shops at around £6.

• A couple of lengths of wire – suggest about 1 foot of black and about 3 feet of red.

• An in line fuse – preferably waterproof.

• Electrical terminals – 2 ring type to fit the battery terminals, and 4 female spade terminals (3 to fit the relay and 1 to fit the starter solenoid), although I understand some solenoids are fitted with a ring terminal also – please check.

 

Method:-

1. First disconnect the battery. You should disconnect the negative (Black) lead first. You will normally need a couple of either 10mm or 11mm spanners.

 

2. Attach the relay to the ‘ledge’ in front of the battery in the centre i.e. around middle of battery. The relay is attached using a tag with a hole in it, which is normally fitted to or supplied with the relay. I prefer to fix using a pop rivet, but you can use a self-tapping screw or a small nut and bolt if you don’t have a pop rivet gun.

 

3. Detach the smaller wire (i.e. NOT the big red one) from the rear of the solenoid on the starter. It may be stiff, but should just pull off.

 

4. Reconnect this wire to the terminal on the relay marked 86.

 

5. Connect a long red wire to the terminal on the solenoid (where you previously removed the wire – see 3 above) and connect the other end to terminal on relay marked 87.

 

6. Connect the wire with the in line fuse to terminal 30 on the relay and the other end to the positive terminal of the battery (using a ring terminal) along with the wire(s) that you originally removed.

 

****** It is important to reconnect the positive terminal first ******

 

7. Using the short length of black wire connect terminal 85 of the relay to the negative terminal of the battery along with the wire(s) that you originally removed.

 

8. Check that all connections are secure and “tidy up” the wires using tape or cable ties, making sure that wires are kept well away from the exhaust.

 

9. Your car should now be ready for use. Start in the normal manner, but don’t forget that you’ll probably have to reset the immobiliser after disconnecting the battery. This is normally achieved by pressing the ‘plip’ about 4 or 5 times – I’m sure you’re all familiar.

 

One other thing you might need (if you have eyesight like me) is a magnifying glass – the markings on the relays tend to be very, very small!!

 

 

HAPPY STARTING

Paul Richards

 

[Paul Richards]

Just to add - NEVER failed to start after all this time (7 years+).

 

Paul Richards

Area Representative - L.A.D.S. (Lancashire and District Sevens)

LADS Website

Growing old is compulsory - Growing up is optional

[Mick Day]

Hi Paul

 

Glad to hear that you have had the same success as me. My little Magneton fires the engine whether hot or cold again & again & again & again.

 

However I will temper that with the following:

1. I've taken the MFU out of the equation.

2. Every 3 years or so I replace the wiring to the starter.

3. Use a good quality relay of at least 30 amps. Replace every 3 years.

4. If you have a master cut-out switch throw it away as they are another source of problems.

 

Seriously the standard mechanical master cut-out switch can be reliable but it does need replacing on a regular basis. Maybe worth investing in one of the electronic ones??

[Bricol]

I've also bypassed the MFU - new wire direct from ign switch to relay, relay fed direct from battery, and new wire from relay to starter.

 

Original, 8 yr old Caterham starter - after three "clicks" which were three too many, did my mod and several years later, it's fine.

 

Still using original Caterham cables from battery to actually supply 12V power to starter.

 

Starter looks to be in prime position to be cooked by exhaust, especially on long momtorway runs, but seems to be surviving. Having seen the pipes glowing dull red on Emeralds rolling road, I'm surprised it is.

 

Bri

[Jon Crofts]

I just did this minor mod, had the embarrassing click at a petrol station a week ago & had it at Goodwood track day having run the car up to temp, had a noise test, switched off & went for the briefing, came back to the dreaded K click. Never again now.

Starts first time every time now, well worth the 40 mins & £6 investment!

 

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