Spoke too soon? S1 odd noise...

robin · Post by **robin** » Tue May 29, 2007 8:57 am

Take some pictures of your bridging links installed and post them will you?

Cheers,
Robin

timmsky · Post by **timmsky** » Tue May 29, 2007 9:03 am

robin wrote:Take some pictures of your bridging links installed and post them will you?

Cheers,
Robin

I was just thinking the same. I'll be at home this evening so will do that and link them here tomorrow.

I'll also look at the points earlier too and let you know!

Cheers,
Iain

timmsky · Post by **timmsky** » Mon Jun 04, 2007 2:37 pm

robin wrote:Take some pictures of your bridging links installed and post them will you?

Cheers,
Robin

Here they are:

Here's the latest - after following through your steps again, this time with the link in place, it falls down at the MFRU step, i.e. indicating there may be an issue with the MFRU or the wires to it. The wires look okay, so could it be possible that it's the starter solenoid relay thats gubbed?

With the links in, the fuel pump primes when the ignition is switched on, but the car won't crank.
With the links out, the pump won't prime and she still won't crank.

Crossing the starter poles with a heavy screwdriver spins the starter as expected.

I'm still thinking that trailering it down would be the best option

Should I buy a new MFRO (£30 ish) to eliminate that completely?

Cheers,
Iain

robin · Post by **robin** » Mon Jun 04, 2007 6:27 pm

timmsky wrote:
Here's the latest - after following through your steps again, this time with the link in place, it falls down at the MFRU step, i.e. indicating there may be an issue with the MFRU or the wires to it. The wires look okay, so could it be possible that it's the starter solenoid relay thats gubbed?

With the links in, the fuel pump primes when the ignition is switched on, but the car won't crank.
With the links out, the pump won't prime and she still won't crank.

Crossing the starter poles with a heavy screwdriver spins the starter as expected.

I'm still thinking that trailering it down would be the best option

Should I buy a new MFRO (£30 ish) to eliminate that completely?

Cheers,
Iain

Next locate the MFRU (at the bottom of the ECU plate). Pop off the connector that has both a purple & white and a brown & silver wire running through it. Inspect for corrosion. Check that the purple & white (position 4 in this connector) is live. Using a short wire link of reasonable gauge, short across to the brown & silver wire (position 1 in the same block). The fuel pump should run. If it does then you either have a faulty MFRU or a problem with the wiring controlling it (neither is likely given where we have gotten to already). Assuming the pump doesn't run, reconnect the MFRU and carry on.

You say fails at the MFRU stage, which I have quoted above. Does that mean that the starter runs when you bridge across from purple&white to brown&silver?

Or something else?

Cheers,
Robin

timmsky · Post by **timmsky** » Mon Jun 04, 2007 7:43 pm

Can't get the starter to turn at all on the key.

The purple/white (posn 4) is live.

Shorting across posn 1 - posn 4 does cause the fuel pump to run.

When the bridge is in, the fuel pump primes on the key.

With the bridge out, the fuel pump will not prime on the key.

Neither scenario causes the starter to crank.

robin · Post by **robin** » Mon Jun 04, 2007 8:28 pm

OK, it's all coming back to me now - we were chasing a fuel pump fault that has cleared itself. Now we're chasing a starter fault that has presented itself. None of the tests were designed to test the starter circuit.

BTW, the starter won't turn unless you disarm the immobiliser - even if you have bypassed the immobiliser relay with the bridges like you have.

You will be pleased to hear that testing the starter circuit is much the same stylee as testing the fuel pump:

Locate EHC2 - that is the two pin connector that lives next to the black and blue EHCs. It has two brown wires on each side. Split the connector and check for corrosion. With the ignition off, check that both of the female terminals are live. Reconnect plug.

Disconnect the MFRU - on the larger of the two connectors there are two brown wires running into positions 6 and 7. Check these are both live and that there is no corrosion.

Using trusty jump wire connect from either of these brown wires to pin 5 on the same connector, which is brown&red. The starter should run. If it doesn't the problem is in the wiring from MFRU to starter.

Assuming the starter runs then the problem is in the control circuit or the MFRU itself. Refit the MFRU. Turn on the ignition, wait for the fuel pump to finish priming. Then turn the key to the start position - you should hear the start relay click; release the key back to the run position - you should hear the start relay drop out. Repeat a few times to convince yourself you can hear it clicking. If necessary have someone else turn the key and hold onto the MFRU yourself to feel the click - note that you mustn't turn the key back past the run position, else you'll get a whole host of other clicks from the MFRU.

If it does click but the starter doesn't run the MFRU is gubbed.

If it doesn't click then there are three possible problems:

(1) Start relay gubbed.
(2) Lucas unit gubbed/not being immobilised.
(3) Crank circuit interrupted from switch to MFRU.

Locate EHC 1 (blue). Pin 3 is a black wire on one side and a white&red wire on the other side. If you can, get someone to turn the key to the start position - the black wire in Pin 3 should go to +12 when you do and return to 0 when the key is released. This eliminates (3). If the voltage doesn't go to +12 when the key is turned to crank position then there is a break in the wiring - and yes, that's where your bridging link is installed so that would be my first port of call.

Assuming that's OK, Pin 10 is a black & white wire on one side and black on the other. If you have your trusty jump wire, jump +12 to the white&red wire and with another jump ground to the black&white wire. The start relay should click and the starter should turn. This eliminates (1).

That leaves (2) - now if you just want the flipping thing to work, you can cut the black wire at pin 10 and run to a permanent ground connection (e.g. on the earthing stud very near the EHC's). Then the start relay will turn no matter what the alarm/immobiliser think.

Cheers,
Robin

timmsky · Post by **timmsky** » Mon Jun 04, 2007 9:15 pm

Thanks Robin, it's like a frickin wild goose chase eh?

I'll give these a go tomorrow and let you know... i'm off work with a gubbed foot at present after battering off a swimming pool floor

I was disarming the immobiliser before trying to crank the starter off the key

Cheers,
Iain

timmsky · Post by **timmsky** » Tue Jun 05, 2007 1:59 pm

Well, I worked all the way through that list right up to and including cutting the black/white wire at posn 10 and earthing at the ECU stud.

The car now primes the fuel pump and cranks but won't fire.

It has nearly started a couple of times, so I thought she was flooded. I took out the plugs and they were soaked so dried them off and put them back in after leaving the plug ports open for a few minutes.

Tried again and still not firing. Seems to me now it must be something very basic, like the cylinders are flooded. I've left her sitting for a while this afternoon and will try firing her up later on today.

We're getting close....

Thanks again,
Cheers,
Iain

Rich H · Post by **Rich H** » Tue Jun 05, 2007 2:32 pm

Sparky? You now have starter and fuel...

HTH
Rich

robin · Post by **robin** » Tue Jun 05, 2007 4:22 pm

If the thing that made the starter work was cutting black/white wire at position 10 and earthing, then your alarm wasn't pulling that pin low when it saw the plip. It is then highly probable that your ECU is also not seeing the code, and then it won't spark.

I know you had the ECU and 5AS mated, but I wonder if the alarm/5AS are actually working in response to your inputs. I assume you have the master key turned to off (early enough car to have such a thing) and I assume you have tried touching the fob to the receptacle on the cowling next to the ignition key rather than relying on the transmitters? NOTE: only touch the fob to the receptacle if you have a master alarm switch - later cars had the same fob but it is used to clear the transmitter matching and not to make the car start

Cheers,
Robin

timmsky · Post by **timmsky** » Tue Jun 05, 2007 5:42 pm

RICHARDHUMBLE wrote:Sparky? You now have starter and fuel...

HTH
Rich

Got a spark, we tested that a couple of weeks back, I think it's something either very fundamental (but everything else 'simple' checks out) or it's as Robin suggested.

Where is the master key and how do you disarm/disable/switch it off?

Cheers,
Iain

robin · Post by **robin** » Wed Jun 06, 2007 12:21 pm

The master alarm key is under the dash in the pax footwell - it's a small key similar in size to the fuel cap key but with a black plastic cover rather than bare metal.

Switching the alarm off this way is not likely to make a difference to your problem, though, as it only affects the intrusion detection, not the immobiliser functionality (in your case, that's just the ECU code lock now, as you have bypassed the immob relay and the alarm earth to the start relay).

I mentioned it mostly because the model of S1 that has the master alarm switch also uses the touch fob as an emergency replacement for the plips when the plips are missing/broken.

Later S1s don't have the master alarm switch and they also use the touch fob to clear the key programming and not as an emergency replacement for the plips. If the plips still turn the red alarm light on the dash on/off then you know they are working.

To me it sounds as though your Lucas 5AS is dodgy and although you had it running when Bob gave you a hand it's since gone belly up again and is now refusing to issue a code - OR - there is a broken wire between the code transmit on the 5AS and the ECU - but that's a bugger to trace.

Looking for the code on the code wire to the ECU requires an oscilloscope or similar edge triggered capture device; unless you can get someone who knows how to use one over, I don't know how you're going to find out whether or not the code is being sent during startup (the emerald has a code learning function and so in a way it tells you whether or not a code is present - I'll chase emerald and see whether they are close to being finished with my unit).

Cheers,
Robin

timmsky · Post by **timmsky** » Wed Jun 06, 2007 1:21 pm

Thanks Robin,

I am not sure whether mine has the master key, I will check, however the fob for the steering column touch pad thingy works fine, at least it turns the alarm light off and allows cranking in the same way the plip does...

How much would a new loom be?

I guess an Emerald would tell me quickly as my oscilloscope went tits up a long time ago

So close... yet so very far......bugger.
Cheers,
Iain

robin · Post by **robin** » Wed Jun 06, 2007 4:31 pm

I don't even think Lotus would supply a replacement loom - if they did, expect no change from 500 quid - in any case, you wouldn't go that way - if you knew the wire was broken, you would graft a new wire onto the loom to bypass the stretch with the break in it, or locate the actual break, clean up the wire and crimp with a butt splice thingmy.

Cheers,
Robin

timmsky · Post by **timmsky** » Thu Jun 07, 2007 8:18 am

Had a looky last night and can't see a master key housing, covered or not

Also a cursory glance between the seats told me that the there was no interior sensor either

I think it would be silly at this stage to order up a new 5AS unit, espercially since it may not be that... Avon confirmed that they did not find anything untoward with either the MEMs (no strange events in log) or with the 5AS which they said they had no problem matching...

I reckon putting the Emerald on to test could save a lot of head-scratching at this stage

You'd think with a spark, and fuel and air you should have the perfect combination for something to happen... but it just 'aint.....

Cheers,
Iain