1.8 16V turns over but won't start; no history of problems

[jamesoff 10]

Was going to take the car for a drive to make sure it was OK after I got back from being away for a couple of weeks. Last time I drove the car was just over a fortnight ago and it's been parked on the road outside my house all that time. Never had a problem starting it before, it usually starts in a second or so. Didn't notice any issues with it when I drove it last (West London to Bracknell and back). The night before that I used some spray-on engine cleaner and a bottle of water with a spray to clean it off, but it started fine immediately after that (and then did the Bracknell trip the next day).

 

Today it just turns over but doesn't catch. Doesn't sound like it's struggling (although I'm not sure how long until the battery starts complaining), just turns and turns. No sign of it coughing but failing to get going or anything like that.

 

Pulled the plugs and they seem fine (dry, but it took me a little while to sort out things I needed to remove them). Pulled an injector and put it in a tumbler while I turned the engine over and there was some fuel in there afterwards. Also cracked the banjo bolt on the cold-start (I think) injector and there's definitely fuel around. Some smell of fuel after starting attempts too.

 

Took the dizzy apart and cleaned it/tidied up the terminals. Checked all the HT cables are seated properly at both ends. Tried Easy Start spray. No change :( All the cables/connectors around the coil and various things that end of the engine look fine.

 

Popped the plug for the hall sender on the dizzy and there was some oily residue in there. Gave both sides a clean and a wipe out but that hasn't helped either.

 

Help? :)

 

(Would be less annoyed if I hadn't just booked in for Saturday morning to have the front tyres done, may have to cancel that tomorrow now.)

[aide 0]

Check for spark too lad. 16vs can be buggers to start when they've been stood a while.

[jamesoff 10]

Thanks, will do. Pull a spark plug out, reattach to the lead and earth it on something like the manifold? Guessing it's a two-man job (one to do that and one to turn the key)?

 

If that IS the issue, is there a common fault for it?

[aide 0]

yeh two person and earth on manifold, or buy some bulb spark testers or similar from halfords if your on your own

 

all my starting problems were nearly always fuel related, there's a heap of wee sensors on the 16v that fail over time, a combination of failures can make infrequent starting difficult.

[vw rule 19]

Hello James,

 

so have you got a spark ?

 

You've said that you have fuel as you've checked that by removing an injector and cranking off the cold start fuel pipe bolt.

 

Your engine might be turning over but if the battery if half drained,

that can some times affect it coursing it not to start.

I had that on my Corrado about 5 years ago it was just dumping fuel in and flooding the cylinders,

and the engine was cranking over fairly ok.

Charged my battery up and she then started first time.

 

On a lot of these Corrado's they don't seem to be able to hold there charge complete for very long,

a lot do suffer with a unknown power drain which drain the battery slowly over time.

 

There's the coolant temp switch which can play up if they've been fitted for years,

when there warn out they course the injection system to just dump fuel in.

 

There's also the metering head unit,

this is where the fuel governor is and fuel distributor and air flow meter are, it's on top of the air filter box.

You say you have fuel and that you can smell it so I would say the governor and fuel distributor should be ok,

but your air flow meter may not be ?

 

These air flow meters do wear out due to constant friction, in the top of the metering head there is a round disc / dome,

this opens up once the engine is cranked / cranking,

the disc / dome is attached to a arm which makes contact with the air flow meter by sliding across it's face,

what happens over thousands of miles is the surface contacts wear out,

but you can still start the car some times by just holding the disc / dome almost closed, as the contact there should be fairly good,

this is because the most wear is in the centre of the air flow meter where that arm meets the contact face.

 

The symptom of this is no fuel at all or very slight fuel and car won't start.

I'm not saying this is the issue with your Corrado but I would check the operation of the metering head, just in case.

 

Really mate just check the basics first before you dive in too deep,

 

check for spark (check your distributor cap inside for damp and cracks plus rotor arm)

check for spark from spark plugs, also see how strong the spark is at the ignition coil,

simply remove the king HT lead from the distributor cap and earth out on engine bracket or valve cover or manifold.

 

Pick up sensor which is attached to number 1 or 4 HT lead can fail coursing engine to misfire or not start at all,

it acts as a pulse sensor as it's checking the coil is firing, which in turn tells the ECU (control unit) to fire fuel governor / distributor.

 

It's a similar sensor to that on the VR6 which has a crank sensor,

this detects rotation i.e by crank pulley teeth passing it and making it pulse.

 

check for fuel (you can still have fuel to injectors but if the fuel pressure is weak, that can be an issue)

check compressions (always do this with the throttle peddle down full and disconnect the fuel pump plug or relay)

check earth leads are in good condition and all connected

check valve timing (a tensioner can come lose or move at any time, meaning cam belt could be lose and timing is out)

check that the alarm and immobilizer is disarming if one is fitted

check battery is charged (as a weak battery can still turn an engine over, but still my not start)

check for power to sensors ( on the 16 valvers mainly the coolant temp switch & metering head unit, plus the hall sendor )

 

Also have a quick check of your fuses just in case it's a simple fix.

 

Can you always here the fuel pump / pumps running when your cranking over the engine ??

 

 

 

Hope this hopes.

 

Si :thumbleft:

[jamesoff 10]

Cheers both for your input. I had the car booked in for having the tyres done on Saturday morning so Friday evening (having not had any luck getting it started still) the garage came and picked it up for me and said they'd have a look at it not starting too.

 

However, it seems they have the magic touch as the second it was off the truck, they turned the key and it started, and it was fine Saturday too so I went to collect it. It's started several times fine since and is running just as it was. Glad it's ok again, but I really don't like not knowing what was wrong in the first place.

 

Thanks for the giant list of things to try Si, that's going in my collection of Corrado info :) Just wanted to check a point about the pick-up sensor on HT lead 1/4 - I found some other threads talking about this so did some investigating and it looks like on the 16V I shouldn't have that, but instead I have the Hall sensor as part of the distributor? Either way, I don't have a sensor attached to any of my HT leads.

 

I don't *think* I had a spark, but that's assuming I was earthing the spark plug when I was testing it correctly. I definitely didn't see one. I did check the fuses and they were all ok. Next time I'll try the test with the lead from the coil instead (or first).

 

Does anyone know a competent garage, ideally in NW London (or Aylesbury) which knows their Corrados and could do a health check? That is, someone who knows these kind of gotchas and can see if it looks like I'm suffering them (or I'm about to).

 

Fingers crossed it doesn't happen again, anyway :)

 

---------- Post added at 6:23 PM ---------- Previous post was at 4:38 PM ----------

 

Spoke to soon - just went out to try it again, and it's not starting again. Arrgh.

[vw rule 19]

Oh brill nice one mate she runs again.

 

Might be spark or fuel delivery becoming a little weak some where ?

 

Yeah the spark plugs on the 16 valves have double or triple electrodes,

these plugs should really last for around 15,000 to 20,000 miles before they need replacing,

on these plugs you can not adjust the clearance gap because it's set when there made from new.

The centre contact on these plugs should be round but over time after 12,000 miles or more the contact will become oval which is normally when you replace them.

 

I believe you can purchase the single electrode spark plugs for the 16 valves,

but these don't normally last as long, and again you shouldn't really adjust the clearance gap on these either,

the gap on these is set to 0.9mm or max 1.0mm from new, it should say that on the box.

 

If you haven't replaced your plugs in a wile then it might be a good idea to get some just in case,

a good set will cost you £12.00 to £20.00

 

Bosch plugs are single or double electrode.

 

NGK plugs are normally double or triple electrode.

 

Yeah thinking about it I don't think the early 16 valves mainly the MK2 Golfs had the pick up / knock control reference sensor on HT lead 1 or 4,

a lot of the later MK2 Golfs did though as that was the KR engine with 139 BHP,

I think the earlier engines were engine codes PL or PU which had 130 BHP, don't think they used these engines in the early Corrado from 1989 to 1992,

believe they used the KR engine on the 1.8 16v Corrado.

 

Here are some photo's just for future reference in case anyone needs them.

 

[ATTACH]74832[/ATTACH][ATTACH]74833[/ATTACH][ATTACH]74834[/ATTACH][ATTACH]74835[/ATTACH][ATTACH]74836[/ATTACH][ATTACH]74837[/ATTACH]

 

 

Si

[jamesoff 10]

Cheers. Went and had a prod and the temperature sensor in the side of the block which is topmost and frontmost (top left if you're looking at the engine from that side). Could only get a reading of 600ish Ohms, and the Haynes manual says (for the KR engine) they should be 1000 at 20C and lower if they're warmer. It's definitely not warmer than that out there. However, while removing it to see if I could clean up the corroded connector a bit, it literally fell apart in my hands so I now have a bolt and a copper spade :)

 

It looks like these are the things: http://www.gsfcarparts.com/parts/cooling-heating/cooling-system/coolant-temperature-sensor so if that's correct I'll get three ordered and replace all the sensors in one go. The other two are reading 950-1050 Ohms but are also in a bad state so I may as well do them all.

 

Is the one which broke the one which drives the dash temperature display? If so, I don't care for now. However, if it's one that the fan or something else relies on, I'll swap the connectors around.

 

Running out of light and it's trying to rain on me so I'm stopping now, although I'm tempted to go bounce on the boot sill a bit in case what fixed it before was the physical process of being moved on to the recovery truck (fuel and crap sloshing around in tank?)

 

I'll retest the spark at the leads and plugs tomorrow when I can get my housemate to help with turning the key.

 

The plugs I have in there were replaced last year, and they're single electrode Bosch. Bought them based on what the Haynes manual said for the KR engine and they looked identical to the outgoing ones except clean.

[vw rule 19]

Regarding your link to GSF CAR PARTS.

 

The top sendor is for the coolant temp gauge Part No : 929VG0090

These are normally in the cylinder head just under the distributor and have one male flat circler spade connector.

 

The lower sensor is the coolant temp sendor (Thermal Transmitter) Part No : 929VG0110 (this is for the 8v not 16v)

These are normally blue or white in colour and have a twin spade connection,

they fit in the cylinder head almost next to the temp sendor above or can be in one of the black plastic coolant housings if it's a 8v engine.

 

This one for sale at GSF (Part No : 929VG0110) I think is for the 8v as it is held in by a metal retaining clip,

normally the 16v's have the coolant temp switch that screws in to the cylinder head almost next to the temp gauge sendor.

 

 

Yeah on most temp sendors the resistance should be fairly high when cold 200 ohms or 300 ohms or above is normally fine,

and once the engine is running and the coolant starts to heat up you should see the readings come down way below 100 ohms.

 

As long as the resistance drops down when the coolant heats up then that is a good sign that the coolant sensor / sensors are working fine,

if not then they need eplacing.

 

 

 

Hope this helps.

 

Si

[davidwort 0]

A 16v that has stood can have a fuel delivery problems on starting as overtime the fuel pressure in the system drops. The metering heads just seem to stick, but with the right technique of priming and repriming the pump you can usually coax them back to life, it's usually a problem if the whole thing as been stripped down, so perhaps your fuel pressure accumulator is getting a bit tired.

[jamesoff 10]

Si: Yeah this one only had a single connection but it was a copper tab sticking out (now broken off), but I think I saw someone asking elsewhere on here/Internet about that and someone else said you could take the plastic part off the connector on the wire, and be left with something which will connect to that GSF sensor (the ...090 one). If that's the right one I'll get one ordered.

 

(My car doesn't match your Coolant temp switch.jpg scan, I have three sensors separately. I'll grab a pic tomorrow so you can see what I mean.)

 

 

David: Do you mean just to turn the ignition on/off a couple of times in a row to try to free up whatever's getting stuck?

 

Thanks again both :)

 

Edit: here's a thread I had open in another tab regarding the three being interchangable: http://www.golfgtiforum.co.uk/index.php?topic=139265.0

Edited June 23, 2013 by jamesoff

[davidwort 0]

yep, I failed to start mine after a long rebuild, dad came around, turned the ignition on and off several times and it fired up fine, pleased but annoyed it was just my starting technique that was wrong :) but to be fair he had worked on K-jets for years and years so knows a few tricks :)

[tony_ack 0]

Yep, all three coolant temp senders on the side of the head are the same rating - one is for the dash gauge, two are for the idle valve/WUR I think? You can swap them over without issue, and it will also help you to identify the duff senders.

 

While you're at it, check all the wiring from the temp senders to the idle valve and themotime switch - it gets very brittle after 20+ years and can cause no end of starting problems.

[jamesoff 10]

Tried the repeatedly-priming trick and that hasn't made a difference.

 

Should the lifter pump in the tank make any noise when it starts/runs? There's a very definite sound of the pump under the car starting and running when I turn the key, but nothing from the one in the tank. Checked with a mate listening there after I pulled the carpet and the round cover off, and also put my hand on it to see if I could detect any vibration of it running.

 

Getting battery voltage (10V at the moment after all the attempts, going to have to go buy a charger soon) between the outermost two terminals on the connector so I assume that's power getting to it OK.

 

--EDIT--

Answered my own question by pulling the hose off the lift pump and running one from it into a bottle. Result after a few seconds of ignition being on: a cm of fuel in the bottle.

--EDIT--

 

Regarding the coolant sensors, good to know they're interchangable. Is the one which broke the one for the dash? If not, I'll swap it with one of the others while I sort out a replacement. See below :)

 

 

 

Further edit: housemate came home so borrowed him and repeated the spark test. Earthing plug against bolt for earth strap = no spark. Holding HT lead from coil near same bolt when ignition is cycled = pretty serious spark.

 

Inside of distributor is pretty clean, couldn't get a good shot of the points in the low light but they're not bad; I did clean them up a bit recently. There's a crack across the centre of the outer covering though. Also, the metal ring inside (behind the plastic cover, which is loose) looks warped. Will pop along to GSF on Wed and grab a new cap I guess.

 

Edited June 24, 2013 by jamesoff

[vw rule 19]

Main power supply should be around 12 volts DC to fuel tank lift pump,

you should be able to hear it working a long with the main fuel pump which is next to the fuel filter under the car.

Like you say you may need to charge your battery up a little.

 

The fuel pumps should prime up the fuel system for around 4 to 6 seconds once ignition is switched on,

if the car won't start then you may need to reprime the system plus pressing on and off throttle peddle,

or keeping the throttle peddle down a little can help to get her going,

but you shouldn't have to do that really, the system should be enough to start the engine.

 

The things that give the fuel system it's pressure is the fuel pressure regulator and the fuel accumulator,

the pressure regulator is attached to the metering head on the 2.0 16v, and the same for the 1.8 16v,

although some 1.8 16v's do have the pressure regulator attached to engine block, very similar to that on the Audi 80 (1988 to 1990)

Looks like you've got this type attached to your engine block in your photo (it has the red fuel pipes fixed to it)

 

The accumulator is next to the main pump under car (external fuel pump)

if pressure regulator is weak it can let too much fuel through which can course slight misfire or slight black smoke from exhaust,

or if it completely fails then car won't start as there will be no pressure in the return fuel line back to tank.

Fuel accumulator when they are weak will course bad or rough starting (engine may turn over for longer until it catches)

You can have a similar issue even when the engine is warm.

I had this issue with mine so replaced it late last year in 2012

VW Part number I think is ( V447 133 441 ) £117.32 price from 2012 (this was for 2.0 16v) but might be the same as 1.8 16v

depends on what pressure it runs at as I think there is a slight difference in pressure rating between the 1.8 & 2.0

 

Been looking at a wiring diagram for the 1.8 16v and I believe the wire to the temp gauge is the (yellow / red) wire,

the one that has broken. (I think on the 2.0 16v's it's the yellow wire)

If you earth that wire on to the engine you should see the temp gauge go up.

 

The other two wires go to the coolant / fuel control unit on your 1.8, I think as they're the coolant temp sendors,

on the 2.0 16v it only has the two coolant temp sendors, one for the temp gauge & the other for the fuel delivery when cold / hot i.e (thermal transmitter)

 

You should get a spark from the spark plug when you earth it straight to the engine,

you need to earth it to a bolt or they can spark off the valve cover.

The king HT lead should always earth out and spark easily but only if the ignition coil is working of course.

 

Yeah your rotor arm looks alright but can't see it from the top only the front shot that you've taken,

any cracks in rotor arm or distributor cap no matter how small then replace with new, as it can weaken the spark,

that can course bad starting issues with or with out condensation / damp in the distributor cap.

They are only a few pounds new.

 

Looks like you've got the flash shield missing as well which sits under the rotor arm,

it's not a major issue but it does help to keep the spark or flash and dirt out of the distributor housing where the hall sendor is.

 

Not sure about the metal ring i.e (hall sendor trigger wheel) it may have been removed & refitted at some point,

as there are a few marks and dents on it.

 

 

Hope this helps.

 

Si

[jamesoff 10]

Cheers Si. Going to replace the distributor cap since the outer cover has a crack in it and they're only a tenner. It's the prime suspect (the distributor in general) at the moment based on seeing a spark from the king HT lead but not from a spark plug. I can do the rotor as well - not seen any cracks in it but if it's a couple of quid I might as well. The Haynes manual says you need to crush it and glue the new one on - is that correct?

 

The flash shield doesn't stay clipped on when you take the cap off, but I have it and I put it back in place when I replace the cap.

 

Is there an easy way to test the Hall sender? I think I read somewhere if it's acting up it stops the engine management (such as it is) working right?

[vw rule 19]

Alright I see so not really a spark or not for very long from spark plug it's self,

could be a faulty hall sensor like you say in the distributor.

 

Three wires to the hall sensor (brown = earth) (red = power) (green = I think is the hall sensor signal transmitter wire)

 

Switch ignition on you should have a good earth on the brown wire,

if using a power probe the LED will go green to confirm this, and red if put on to power wire.

 

Or if using a multimeter set it to 20 volts DC,

right if you put red test lead on to red wire,

and black test lead on to the brown wire this should say 12v to confirm good power & earth,

 

then to check operation of the hall sensor you might want to unbolt the distributor,

so you'll be able to rotate the rotor arm (to spin it)

or crank engine over via key but you might need another pair of heads to help.

 

To test it leave the black test lead on the brown wire (earth)

and move the red test lead off the red wire & put on to the green wire,

now if you rotate (spin) the rotor arm you should see the voltage go up and down,

as the trigger plate / wheel passes the hall sensor,

You should see the two or four cut outs in the sides of the trigger wheel, this makes the hall sensor switch off & on.

If you get no readings on your multimeter then it could be duff.

 

This sensor acts like a magnet because it pulsates off a steel object that is passing over it (hence the trigger wheel)

The crank sensor, cam sensor and ABS sensors are similar as they all pulsate off a steel wheel / plate with cut outs or teeth.

 

 

Yeah the flash shield won't stay on unless the distributor cap is clipped on.

It is best to refit the shield though.

 

 

 

Sorry mate what do you mean by = ( The Haynes manual says you need to crush it and glue the new one on - is that correct? )

You don't normally glue anything on or crush the old one, lol

 

You just have to clean / wipe the distributor shaft (make sure the groove / slot is clean and clear,

or the new rotor arm could be a bit tight to fit on.

Look at the bottom of the rotor arm that fits on the shaft and you'll see a tooth inside which slides in to the shaft,

this is the reason why you should clean / wipe the shaft,

plus put a very small bit of EP grease or oil in the bottom of the new rotor arm or old one if you're still going to use it.

This just makes it a lot easier to get off at a later date.

 

 

Hope this helps.

 

Si :thumbleft:

[davidwort 0]

yeah, on the rotor arm glue thing, VW did originally glue the 16v rotor arm in place but no one ever bothers to do that when replacing them and it doesn't seem to ever cause a problem, I've been bouncing a 16v off the rev limiter for 15 years and never had a rotor arm work loose :)

[jamesoff 10]

Good to know. Picked up a dizzy cap, rotor and a replacement temp sender at GSF this morning so I'll be attacking those this evening when I get home.

[jamesoff 10]

New cap and rotor (came off easily, no glue!) have had no effect unfortunately.

 

Getting battery voltage across the live and earth on the Hall sensor's connector. However, I wasn't confident of removing (bits of?) the distributor to get it off the car so I could spin it to test - do I need to worry about alignment of bits when I do that, or are they keyed so I can't mess it up? Do I just undo the two bolts either side of the whole thing? The bracket looks like it can be adjusted (rotated) a bit by loosening those bolts, which adds to my fear of getting things misaligned! I am definitely heading out of my comfort zone now :)

 

I did stick my multimeter on the earth/sensor pins of the Hall sender itself and have my housemate crank the engine, but it didn't budge off 0. It's just a basic one but I was hoping to see it change values continuously as it tracked the sensor's output. However, I'm not sure if it should have worked at all given that it had no power connected. I pulled the boot on the connector back but the wires aren't exposed under it so I couldn't measure it with it connected.

 

Hope that makes sense!

 

Someone come and fix my car :( Was watching the Youtube vids of the guy with the red VR6+turbo and wanted to go for a drive!

[vw rule 19]

You should really set the engine to TDC before you remove any distributor,

but as it's the 16v engine you don't have to as the distributor is in the cylinder head,

the distributor drive gear is driven by the cam shaft.

The cam shaft has a off set slot in the end of it which the distributor drive gear fits in to,

so you can't really refit the dizzy incorrectly.

 

Make sure though that you mark the distributor with tippex or use a small chisel,

simply mark on the top of the distributor where it meets against the cylinder head,

or observe the bolt markings on the dizzy, as when their removed they leave a round clean circle mark,

which can be used to help aline the dizzy.

 

Take a look at this link I know it's not the same engine or vehcile as your's,

but it will help / show you regarding the dizzy http://www.autozone.com/autozone/repairguides/Volkswagen-Air-Cooled-1949-1969-Repair-Guide/Engine-Electrical/Distributor/_/P-0900c15280267517

 

If your not 100% sure then please don't remove your distributor, it might be best if you can do the hall sendor test with the dizzy still fitted.

 

 

Yeah it does need to be connected the three pin plug for the hall sender,

or you won't get a reading on your multimeter,

if you can't get your test leads on the contacts then you may have to probe in to the wires using your pointed test leads.

 

Have you 100% not got a spark from any of your plugs or HT leads, but have from your King HT lead from coil ??

Is this 100% correct ??

 

Si

[jamesoff 10]

I'll see about either getting some wires jammed in the plug as I put it on so I can get the probes on them, or something else like you suggest. Failing that, my Dad's coming over this weekend (was supposed to be going to his so we could do CV boots etc which the MOT listed as advisories!) and he has enough competence to be removing the distributor and replacing it correctly.

 

I have definitely had a spark from the king lead (held near the bolt for the earth strap at the engine block end), but not from either of two spark plugs (cyls 1 and 4) held with the thread/bolt against the same earth strap bolt. The latter test I've done a few times now, including last night after replacing the cap/rotor.

[jamesoff 10]

Well the Hall sensor seems OK - I jammed a couple of wires in the connector when I shut it, and then turned the engine over watching my multimeter. With the ignition off, it was showing about 0.4V (!). With the ignition on, battery voltage, and while the engine was turning over it was showing about 6V, which I take to be the average of 0 and 12 - i.e. what you'd see for a switch which is on 50% of the time and off 50% of the time. So I guess that's OK.

 

At this point, my Dad and I were both stumped because we're definitely getting a spark off the king HT lead when you turn the ignition on, and nothing at all at any of the plugs.

 

If anyone has any other ideas for things to try I'd appreciate it, but I think now I'm looking for a good independent VW specialist in the NW of London so if anyone has any recommendations I'd be grateful!

 

:(

[vw rule 19]

Hello mate,

 

Right ok so if you’ve got a spark from the King HT lead,

then the ignition module (ignition amplifier)

and the coil must be ok.

You’ve tested the distributor hall sensor and had power there,

plus saw the voltage change when the engine was cranked over on the green wire.

 

I think if the hall sensor wasn't working you wouldn't be getting a spark from the coil.

6 volts yeah that seams ok for the hall sensor (like I say the coil is working)

 

So the only things now that can stop the spark from the four main HT leads,

is faulty HT leads or plugs or a bad earth ?

 

Warn HT leads normally play up when the engine is running,

and when you apply the throttle you may feel or hear a misfire,

this is because they play up under load and don’t like damp weather when they’re warn.

But in rare cases the HT leads can be totally burnt out.

 

Similar thing happens to the spark plugs over time,

they can be come warn and so produce a weak spark (mainly due to the electrode gap becoming too big)

or the centre core of the plug in side is warn or burnt out.

 

Regarding the earth, the spark plugs are screwed in to the cylinder head,

and so are earthed through the engine it’s self,

so if you’ve got a bad / weak earth then the spark plugs may not be working.

 

But you said you have a good spark from the King HT lead,

when you earth it to the engine,

so for that reason the engine earth should really be ok.

 

You might just have dodgy HT leads or plugs if you’re only getting a spark from cylinder 2 and 3 and nothing from 1 and 4

have you got another set of spark plugs that you can try,

also you can test for continuity through the HT leads using a multimeter,

this tests to make sure there are no breaks in the centre core of the HT leads.

 

I think also you can do a resistance test on the leads as well.

 

Have a feel of the main wiring loom from the fuse box where it comes through the bulk head,

and have a wiggle of the HT leads you could have a dodgy wire somewhere.

 

What I mean is most components work but if the wiring to them has a fault,

that could course the component to stop working intermittently,

but if the car is moved or wiring is then the car could just suddenly start up,

and then when the car is left over a few days it may not start up again ?

 

This can happen with faulty earths to engine.

(wires / cables may look ok but if a continuity test is carried out it can show intermittent faults)

 

 

 

Hope this helps

 

Si

[jamesoff 10]

Thanks Si. I'll maybe unbolt and clean up the engine-end connection of the earth strap to see if that helps, and I'll give the wiring loom a prod too. It's strange how when it was running (before I went away, and also when it worked for a day at the garage) it was running fine without missing a beat. I agree that suggests it's a dodgy connection somewhere that's killing the whole system rather than just say, one of the plugs.

 

I did test the resistance of the leads not long ago when I was considering replacing them (mainly because they look old and I'd like smart new ones) and they were all fine then, but I'll see about retesting them. Don't think I'm getting spark on cyls 2 & 3 though as when it's turning over to start there's no coughing or change in the noise/speed of rotation to suggest some of the cylinders are firing.

 

Making arrangements for Green Garage on the A5 to come get it this week some time, they look pretty competent from their website. May write up everything I've tried (and the fact it sprung to life for a day) as a note for them!