Glowing Ignition Module, Hot Relays, And Non Starter!

[DNCustomGti 0]

Hi,

I need some help! I've got a H reg 1.6 GTI, theres an electrical problem and I hate electrics! (because thats what finished off my Mini, but thats another story!)

 

For a bit now, my pugs been doing things on its own - like when you turn off the engine, you can still hear that hissing/buzzing noise in the back around the fuel tank - is it the fuel pump?

 

But then it stopped all together eventually - I was going down a main road the other day and headlights started flickering, indicators only worked intermittently and for past few days before it died totally, something was running the battery flat - a brand new varta one and a brand new valeo alternator charging it!

 

But anyway,it cut out and all power was lost. managed to park it on edge of road luckily.

Felt at all the relays as mostly it had strange problems as soon as headlights were on i.e. flickering, or indicators would only work if headlight on sometimes.

 

one felt pretty hot, think it was one to do with ignition but maybe that was cos i was holding key on iginition and riggling wires and relays to see if it was just a bad connection.

 

disconnected battery, then reconnected, and all dash lights went off when i turned the key to on. almost like something had reset itself.

 

but soon as i went to start it agen, all dash lights came on, but no actual power to headlights or starter was getting through, just dash lights. accept for the front windscreen wipers which i couldnt turn off, not even with them turned off on steering column.

 

had a look around all connections under bonnet and saw (because it was dark) that ignition module, i think its ducelier type, was glowing/constant spark inside.

its the one that is on passenger side wing. RHS as you look from in front of the car. Its screwed onto chassis, and i could see down the back of it that it was glowing.

at this point i just thought im gonna have to get a new one and fit it at the side of the road then get it back for a check over. so i left it and disconnected battery in case it caught fire or burnt something out!

 

went back next day, with experienced pug mechanic and it baffled him a bit aswell.

 

we reconnected battery and tried it. - still the same. so we disconnected and reconnected all the coil, the black donut thing on the intake manifold. had a quick prod at the connections on the module on the passenger side wing, (we could see it was definetly still glowing in the back of the module) and it fired up!

 

unbelieveably it had mended itself!

 

but i cant really go anywhere in it now because i cant trust it.

 

so can anyone please shine a light on this problem or say if they've had the same symptoms because i cant seem to find anyone with this problem!

 

thanks

[DNCustomGti 0]

K, ive had another look and its definetly a ducelier type ignition. I can get a new coil easy enough for 20 quid, but would this cause the module to glow or do i need to see if i can get a module, and see if that solves it.

 

My mechanic says hes seen these modules go before, he thinks its something to do with the weird silicone stuff in the back of them that goes dry and makes the module short all the power across itself. Is this correct?

 

Up to now car still hasnt faulted again, so i'm really stuck as to what to do!

[Rob_the_Sparky 9]

The ignition modules do overheat due to a lack of heat transfer paste on the back of them. You could try some new paste on the back before replacing it. It won't short anything though if there is no paste it will just get too hot and eventually give up the ghost. If it is that hot then there is clearly a problem and I doubt it has much life left in it.

 

You probably also have a Tachyometric relay problem as well if the fuel pump is staying on with the engine stopped. The tachy is meant to only switch it on during cranking or when the engine is running.

 

New coil and ignition module would seem sensible as a starting point...ignition module is around £25 from GSF

 

Rob

[DNCustomGti 0]

Cheers for that.

have managed to get a genuine ducellier brand new one c/o ebay for 15 quid, and coil for 20.

My boss at garage where i work was considerin whether i'd got poor earth problems down around the back of the battery and near the plate that the module bolts onto. almost like somethings trying to earth through the module, which would explain why the battery (brand new) suddenly ran flat once, just few days before everything went dead totally.

 

tachy's are expensive from my supplier, (approx 70 quid!! - way more than i've heard some being sold for!) but i think thats just cos they dont get many in. i'll have to have one tho!

gsf do them dont they?

 

maybe all these new bits will help the well renowoned tick over and cold starting problems that ive got aswell, im sure the tachy problem must be the reason for poor mpg!

 

apart from the odd thrash, its still impossible to do more than about 110 miles on 20 quid and thats really pushin it. ive had the tick over and mixture set-up, new temp sensor, checked all the resistance values as in the haynes manual, has has a 2nd hand afm, and stil no good. im thinkin of tryin another afm, but no one advertises them saying that all the resistance values are within the limits, so you never know of they're gonna be any better.

its not exactly flat where i live, so that wont help it, and most times it gets short runs.

 

where would the fuel go when the pump stays on and the engines turned off?

[Rob_the_Sparky 9]

Tachy's are expensive I'm afraid, think GSF do them but not 100%. A few people have opened up dead ones and found that they were repairable if good with a soldering iron. Not opened one myself though but might be worth a try.

 

The fuel pump always pumps more fuel than needed. There is a pressure regulator on the end of the fuel rail that controls the pressure and the spare fuel returns to the tank. This will not cause execessive fuel consumption.

 

Tick-over is generally down to a combination of igintion timing and mixture at tick-over, generally a bit rich.

 

For economy first thing to check is that the vacuum advance is 1) working 2) the hose from the throttle body to the vac unit has not fallen off at either end (this is common). This will give you a few mpg extra. The rest is probably down to ignition timing and possibly fuel mixture. Cleaning the Air Flow Meter and throttle body may well help as well.

 

Rob

[jonah 1]

My boss at garage where i work was considerin whether i'd got poor earth problems down around the back of the battery and near the plate that the module bolts onto.

I'd say that's almost certainly the cause. From what I remember, the negative cable from the battery goes onto that plate, which in turn is bolted to the chassis and should complete the connection from battery to chassis. so if it's not making a good contact, it may be finding a path to earth through other circuits which could explain all the strange behaviour.

 

Plus if there's something glowing behind there it definitely points to a resistive connection! I absolutely cannot believe it was the ignition module itself glowing, because if it had got that hot there is no way it would have still worked afterwards.

[DNCustomGti 0]

I'd say that's almost certainly the cause. From what I remember, the negative cable from the battery goes onto that plate, which in turn is bolted to the chassis and should complete the connection from battery to chassis. so if it's not making a good contact, it may be finding a path to earth through other circuits which could explain all the strange behaviour.

 

Plus if there's something glowing behind there it definitely points to a resistive connection! I absolutely cannot believe it was the ignition module itself glowing, because if it had got that hot there is no way it would have still worked afterwards.

 

Yeh, wasn't really sure how the modules worked at that point, so what i first observed as glowing must have been a continous sparking down the back of the module where it connects to the conducting plate. Its all a bit squashed down there, so its hard to tell where its coming from, especially now its stopped doing it now!!

 

Your right about the module not working if the glowing was coming from inside it, because its still working now!

What does the module do - like .. whats inside it?

 

Maybe all these problems stem from new battery being fitted, and something being dislodged, or earth wire broken. Because about 2 days after fitting new battery (old one was tested - knackered) something ran it right down flat.

So as a temporary measure if i was going to be parked up for a while, i'd disconnect the battery, and one night i saw the same spark from around the module when i reconnected the battery, this is without having any ignition on.

 

Anyway,

Have got coil now, and waiting for new module so i'll have a bit of an inspection around there when i come to fitting module. Who knows, they mite really be both alright, but its p***in me off that i cant trust ma pug anywhere!

Also, am i just stupid, or does haynes manual not list anything about this type of ignition?

[DNCustomGti 0]

gsf sell part no. T93590 FUEL PUMP RELAY 205 GTi £46.50

 

will this be right? is it same relay for all gti's 1.6 & 1.9's?

Thanks

[Rob_the_Sparky 9]

The ignition amp takes the signal from the distributer and switches the power to the coil in response to it, creating your spark.

 

Fuel pump relay: I guess so as there is only one fuel pump relay on a GTi.

[returnofjim 0]

Have you checked what voltage the alternator is giving out? i had a 205 that the alternator was kicking out 17 volts and made crazy things happen to the electrics, blew an ignition amp, made wipers go fast, and blew bulbs and allsorts, could be worth checking.