No Spark Weirdness

[Guest Quakes]

Right i finished changing the plastic bung on the raditor for an old fan switch as it was leaking. put the afm and all that back on. drove down the street and the revs died out pulled over and started doing checks.

 

I had a Spark so i loosened the fuel line and tried it and there was no fuel so stupidly i decided to check the pump first by running a live wire to it, Pump was fine. so i took the relay by the ecu out and bridged the connection and the pump ran (forgot to tighten the fuel line so sprayed fuel under the bonnet. took the wire out to stop the pump and got a towel to start soaking the petrol up

 

as i did there was loads of sparks on the gear box i %&£$ myself with all the fuel around and ripped the live terminal off. took the afm back off and a brown wire connected to a a black box (that has two fuses inside) had had its plastic cover ripped and the metal had shorted on the gear box to the point that the wire was broken.

 

the fuses were fine i got a terminal connecter and reconnected the wire put the live terminal back on and reconnected the relay by the ecu now the fuel is fine but i have no spark

 

i replaced the coil but still nothing by no spark i mean i have a spark plug in the king lead.

 

what i really need is any ideas what that brown wire is for. what sparks on the gearbox could of fried.

 

before i spend money on a new amp

 

Cheers Jono

 

Also the sunroof stopped working at the same time the air thingy it wont seal now if thats any help.

Edited October 4, 2006 by Quakes

[inferno 1]

the "air thingy" utilises engine vacuum, so if it hasnt been running and you open and close it 2 or 3 times it now has no vacuum and wont seal

[Guest Quakes]

ahh cool was hoping it would be curcuit related hmm just gotta find out what i could of broken

[Pugnut 9 1 Cars]

the "air thingy" utilises engine vacuum, so if it hasnt been running and you open and close it 2 or 3 times it now has no vacuum and wont seal

 

just to be anal , it works the other way round . the vacuum sucks the seal down so the roof can open freely. still unrelated.

 

it been a while but iirc the box with brown wires you mention is the feed for the fan(s)

 

you metioned initially that there was a spark but no fuel at the rail .then you bridged the tachymetric relay out and the pump ran and pumped fuel . By that i would say the tachometric relay was the culprit. dunno why you've got no spark now . have you checked that the fuel pump runs when you crank the engine? you really need to be there with these kind of problems!

[Guest Quakes]

it pressurises when you turn the key and runs when you crank. could the relay cause no spark? looks like ill pick up an amp tommorow still cant see it being at fault unless the short on the gearbox fried it.

 

Does anyone know where all the wires on the ignition coil (not the manifold mount type) go? 1 goes to the gearbox for earth i need to check the rest.

 

My car got broken into a few days ago and all was taken stereo subs toolkit they even took my multimeter and my locking nut so things are sorta hard at the moment

[Guest Quakes]

with the wire im on about to be more specific theres a box that has a wire coming of it going to the battery and it has plugs coming off it one of which is a brown one that runs over the gear box and into the loom. the connectors are the same type as the fan connector the brown ( atleast it looks brown ) comes out of one of these connectors and carrys 12v also theres two 25amp fuses inside the black box.

 

Sorry cant think of any other way to describe it

 

Cheers Jono

Edited October 5, 2006 by Quakes

[Guest Quakes]

Ive just replaced the amp so that can be ruled out im really miffed now gonna replace the fuel pump relay tommorow any ideas?

[steve@cornwall 100]

with the wire im on about to be more specific theres a box that has a wire coming of it going to the battery and it has plugs coming off it one of which is a brown one that runs over the gear box and into the loom. the connectors are the same type as the fan connector the brown ( atleast it looks brown ) comes out of one of these connectors and carrys 12v also theres two 25amp fuses inside the black box.

 

Sorry cant think of any other way to describe it

 

Cheers Jono

 

sounds like the box that should be mounted on the slam-panel. got a k+n by any chance? these boxes are often left to float around when a k+n is "thrown" in. I think this supplies the main fuseboard, and therefore just about everything! I would try and find a sympathetic gti owner to swap relays, ecu etc if at all possible. Sorry if this post is the voice of doom!

[ORB 227 1 Cars]

Have you tried shouting at it and calling it names? and if that fails, hitting random and unassociated stuff with a hammer?

 

I find this helps with most issues.

[Pugnut 9 1 Cars]

if the fuel pump runs while cranking it isnt the relay. the fuel pump relay needs a tach signal to operate but wont stop a spark bieng generated .

 

the spark side of things are totally seperate from the ecu also (other than the ecu also needs a tach signal)

 

so if you're not generating a spark but the tach relay is operating then you need to be looking at the amplifier, coil and associated wiring . do you have 12v to the coil with the ignition on ?

[Guest Quakes]

replaced amp and coil already :/ will have to go buy another multimeter tommorow just to be sure the negative is obviously 12v when tested against positive and the ignition coil should be constant 12v? when ignitions on im checking the internet at the mo to find out where the red cables go if they are the problem im gonna need to trace them. do they use a relay?

[Guest Quakes]

Right been down to the car today couldnt get hold of a multimeter yet so tried the thin wire quick contact method with ignition on one of the red wires going to the ignition coil carrys 12v without ignition on it carrys nothing

 

the other red wire always carrys nothing.

 

the negative side of the coil is always grounded.

 

i had a spare relay of the green one to the right of the expansion tank so tried that still nothing.

 

I really need to know everything that needs to be satisfied to get a spark

 

could it be anything to do with the fuse box or the relays in the fuse box?

 

the dizzy couldnt cause it if im looking for a spark off the king lead could it?.

 

sorry for all the questions im just getting short fused with this problem

 

Cheers all Jono

[Guest Quakes]

Anyone :/ ive run out of ideas now dont know what else to try.

[welshpug 1,657]

brown multiplug

[Guest Quakes]

ive pulled it apart cleaned it put it together its weird that mutliplug is usually the cause of my problems

 

ive done more testing today.

 

first the rev counter dosent move when i try to turn it over ( new amp ) so im guessing its not getting a feed to the amp.

 

and the 4 wires to the coil are.

 

1. (Red) has 12v when ignition is on

 

2.(Red) has nothing im guessing thats the wire that passes 12v to the amp

 

3. (Green) NOTHING !

 

4. (Green) NOTHING !

 

So im guessing the green wires (no earth to the coil) is where my problem lies ive checked them and one goes into the fuel pump relay ( the big black relay by the ecu )

and the other goes into the ecu i think.

 

Is the tach relay the green one by the expansion tank?

 

could the fuel pump relay be stopping the coil getting its earth or the ecu?

 

Cheers Jono

Edited October 7, 2006 by Quakes

[Guest Quakes]

Anyone i will have to book it in monday otherwise as i need my car!

[Pugnut 9 1 Cars]

the small wire coming out the front of the distributor carries the signal to the amp. it unscrews from the distributor and goes to a two pin plug before going to the amp . this is where the tacho signal originates but i'm sure that this signal is needed before the fuel pump relay operates . always worth checking out though

[t16ryan 1]

the small wire coming out the front of the distributor carries the signal to the amp

the small wire coming out the front of the distributor carries the signal to the amp

Also check this wire all the way back in the loom wiggling it while some one spins it over and see if rev conter moves, had 3 now where inside the sealed loom two wires touching causing no spark,

Edited October 9, 2006 by t16ryan

[Guest Quakes]

ok a few final questions hopefully

 

if the amp stops the rev counter moving when you try to turn her over what needs to be satisfied for the amp to run?

 

when ignition is on should you get 12v on the positive side of the coil and earth on the negative or just 12v on the positive?

 

can the fuel pump relay or ecu stop you getting a spark?

 

i am so annoyed with this problem now is anyone living in or around cardiff able to come to north cardiff and help for some beer tokens?

 

Cheers guys (as always Jono)

[Swilki 0]

if the amp stops the rev counter moving when you try to turn her over what needs to be satisfied for the amp to run?

 

The wire comes out of the rev counter, through the brown multiplug and goes to the amp. If your amp is working good, clean brown multiplug and your interior clock is working, your rev counter should be good to go.

 

can the fuel pump relay or ecu stop you getting a spark?

 

AFAIK no. The fuel and ignition systems are seperate

 

Since you've replaced the amp already, my bets are on the wire running from the dizzy to the amp, assuming everything else thats obvious (good cap and rotor arm etc) is good

[Guest Quakes]

All sorted it was that wire from the amp to the dizzy i had only been checking it the amp end i looked the dizzy end and underneath the wire had been snipped :/ my car was broken into when it happened and the bonnet was left open but it seems to precise for the ***ards to have cut that wire anyways ill just be glad its working cheers all (as usual)

 

Jono