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Model specific boards => Golf mk3 => Topic started by: Kmad on 09 February 2013, 19:27

Title: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 09 February 2013, 19:27
Hi Guys ! First off all name is Chris. All though i wanted to join this forum in happy mode and circumstances such as moding etc story is different  and i have a huge problem  :sad:

2 weeks ago i bought a lovely clean black ,box standard '96 gti 8v with 100k on the clock..all was good first week although sometimes car would start and cut off but always start second time and i was suspecting some flat spots around 4000rpm but that could just be me and it wasn't a big deal!   

One day coming from the pub car refused to start altogether and red oil light flashes....

I have replaced fuel pump relays and resoldered those suspicious ecu relay no30 joints,  checked every fuse ,disconnected ecu end checked conectors,swapped fuel pumps,checked for sparks all good  still nothing :angry:

Weird thing is that when i disconnect the fuel pump and connect it to a direct 12v supply it works ,primes and supplies fuel to engine.Engine then starts no prob runs for minute and then cuts off when it uses all the fuel from the line...
When i check voltages coming into the plug that connects to the pump it shows 12v when ignition is on then it drops to 4V and again goes up to 12v when i crank it!!! But when i connect that same plug into the pump nothing happens pump is dead engine wont start ......what the &€@-,!!?. :evil: :evil: :evil: is going on?????? Someone PLEASE HELP????  Am I going mad!!!???.

Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 10 February 2013, 12:22
Anyone ????  I have been reading all the posts and cant find anything similar, help guys before i burn it  :laugh: :laugh: :laugh:
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Abf83 on 10 February 2013, 12:33
Im not sure on the fuel pump but the oil light flashing is probably the oil pressure switch or could be the wiring to it. Check for any damage on the wire if not change the switch. Just check oil lvl also. Have you checked your fuses? Maybe it could be that.
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 10 February 2013, 12:37
Thanks for the reply man, yeah oil is topped up and all fuses are ok, wiring to the sensor also ok... Would a faulty oil press sensor prevent from starting???
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: boneybradley on 10 February 2013, 13:13
don't worry about the oil switch at the mo, it wont pressure up without the engine running correctly.

To me it does sound like a fuel pump relay issue. Can you test another relay? (never buy used)

The only other things I can suggest you check is the fuel filter for a blockage, check the ignition switch and also look at the immobiliser
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 10 February 2013, 13:29
I have put in another fuel pump relay from a car i know is working 100%, havent checked the fuel filter though...imo ilizer i rhink would cut out ignition but i have spark or maybe i am wrong... Again i am confused that the car starts when i conect the pump to direct 12v supply!!?? Can it be the crank sensor would it cut off fuel id it was faulty??? Thing is when i crank it rev counter goes up ?
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: dixie180 on 10 February 2013, 13:36
If it cuts out and oil light flashes,i would say Crank Sensor is gone(same happened to me).Like boneybradley said,use brand new fuel pump relay.
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: boneybradley on 10 February 2013, 15:39
you could also try and can on vag-com and see if any errors come up.

it may not show your fault but worth a try (I could scan if your close by and others users may offer a free scan if you don't have a reader)
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: itavaltalainen on 10 February 2013, 16:02
check hall sender with a LED test lamp, should nicely flash on centre pin when you crank, if not replace complete distributor where it lives....

quite a common 1.8/2.0 8v issue.
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 10 February 2013, 16:18
Bench tested fuel relay and tested it in in my 1.4 golf which i have for spares all is good... Will test the hall sensor... But still what confuses me is the fact that car starts and works fine when i connect  the pump to a direct 12v source plus all the voltage readings at the plug are correct... :huh: Tomorrow i will take to a garage and have it connected to diagnostics...
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: itavaltalainen on 10 February 2013, 17:38
But still what confuses me is the fact that car starts and works fine when i connect  the pump to a direct 12v source plus all the voltage readings at the plug are correct...

IF it starts with fuel pump directly put to 12V and the relay working correctly then either:

a) fuel pump fuse broken - measure fuse from F18 for continuity

b) connector on back of central electric box is not fully pushed in. take the box out, slide the lock rail out to unlock, make sure they are all pushed in correctly.

c) Check if you get 12V to the fuel pump socket, this would be one of the wider contacts, on one of them you should always have 12V. Check if you get 12V to one of the thinner connector with ignition on.

d) broken wire between ECU and central electrics, or CE and fuel pump in the back.
Measure at various points to check where it is broken.

Also read fault codes with running engine, guessing you got an AGG engine, which has a hall sender in distributor and a separate engine speed sender.
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 10 February 2013, 17:46
Already checked voltage at the fuel pump socket and with ignition on shows 12v for 2-3 sec and then drops to 4v i guess this is the prime cycle, after that when i crank the engine again shows 12v at the socket... This is whats driving me mad !! how is it possible to have them readings but when the pump is pluged in nothing happens pump is dead ???? BTW thanks for all the info guys apriciate !! I will check conectors at the back of the box ....
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Martinvr6 on 10 February 2013, 18:16
At a guess I'd say your ignition switch is knackered.
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 10 February 2013, 18:22
How do i check that ?? I would really love to know ecu logic and what trigers what ...
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 10 February 2013, 18:37
BTW it is an agg engine..
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: boneybradley on 10 February 2013, 18:53
At a guess I'd say your ignition switch is knackered.

usually the best way to test this is wiggle the key while you start it and see if it runs better... another mk3 common fault as they wear out inside the switch! (quite easy to do once the steering wheel is off)
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 11 February 2013, 13:45
Ok will do that!Also tomorrow i am getting it hooked up and gonna read fault codes, maybe ill find something....
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 11 February 2013, 17:55
Anyone know what resistance should i be reading from crank sensor and from what pins???
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: itavaltalainen on 11 February 2013, 18:52
measuring resistance on hall sender does not make sense  :huh:

build youself a test led with 1k resistor and connect the resistor to middle pin, then the LED anode to that, LED cathode to GND..... then get someone to crank it with fuel pump relay removed..... LED should flash at least once a second....
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 11 February 2013, 19:27
Sorry for confusion didnt mean hall sender i ment the engine speed/crank sensor ,the one behind the oil filter...
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 11 February 2013, 19:30
Is it possible that if that sensor is faulty ecu will not signal fuel pump to work??
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: dixie180 on 11 February 2013, 19:44
It tells the ECU which cylinder needs fuel and which one needs a spark,so i guess faulty Crank Sensor would not send a signal to send any fuel to the cylinders.
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 11 February 2013, 19:59
F@£k me i am lost now , checked every part of fuel system electronics there is and everything seems fine! Why the hell am i reading correct voltage at the pump socket but it still wont work is anoying the sh!t out off me... How is this possible??? I am starting to think that when the pump is conected and load comes on something fails in that wireing and not inough curent runs through to run the pump .... I dont know anymore....
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: dixie180 on 11 February 2013, 20:01
If the Crank Sensor is f**ked your fuel pump won't get the signal from the ECU.Did you run the VAGCOM on the engine and if so what fault codes did you get up,if any.


Rob
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 11 February 2013, 20:06
Ok that gives me a bit of hope , tommorow frend is bringin the fault reader and we are going to hook it up... Btw when i connect multimetar to two far outer pins of the crank sensor its reading mega ohms , i dont think thats right but i dont know for shure which pins i should test...
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 11 February 2013, 20:11
BTW guys sorry for misspelling here and there i am originally from Croatia!
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: dixie180 on 11 February 2013, 20:12
Only 2 pins will give you a reading and it should be in the range of 500 to 700 ohms. :grin: no worries bud don't like seeing folk suffering with Mk3 golf rage :laugh:Pins 1 and 3 voltage 9-14.5v.
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 11 February 2013, 20:39
Just tested it and its reading 7.00 mega ohms ... f**ked??
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: dixie180 on 11 February 2013, 20:42
Yep absolutely  :sad:.Probably best to run the diagnostics aswell but new Crank Sensor on the shopping list i think.
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 11 February 2013, 20:44
Ok thanks dixie 180! Hope is back  :smiley:
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: dixie180 on 11 February 2013, 20:46
Hey bud,been in that position myself and does your effing head in.Let me know how it goes.


Rob
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 11 February 2013, 21:19
Ah man i am going nuts, rage stage was already gone depression started kicking in   :grin: :grin: once again thanks .. Will post tomorrow when i get it hooked up...
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: dixie180 on 11 February 2013, 21:24
 :grin: :grin: :grin: :grin: :grin: :grin: :grin:


Rob
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 13 February 2013, 22:14
Still didn't get a chance to hook it up to diag. Been busy at work,finishing late every evening didnt have time to do anithyng and that f**kin rain just keeps on falling  :angry: I was thinking could it be immobiliser cutting fuel off and not the crank sensor??? Because as soon as it has fuel engine starts no prob and the rev counter works normal and i know rev counter picks it up from crank sensor(i confirmed that by plugin it out).could it be immobiliser???
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Simeon on 14 February 2013, 13:49
Has it got or had in the past an aftermarket alarm/immobilisor? These are usually spliced into the fuel pump wiring and if it's been badly removed in the past it could be causing a problem.
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 14 February 2013, 14:48
Yes it does actualy but it seems to be deactivated
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Simeon on 14 February 2013, 15:31
Worth tracing the wiring then.
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 14 February 2013, 19:45
Guys today i hooked it up to a code  reader and there was no faults at all, so i thought thats f**kin weird ....said maybe the battery was disconected so i might crank the engine again and something will come up! Cranked the engine and boom it started straight away no problems!!!  :shocked: went for a drive warmed it up and thore the asshole out off it all good!!! As much as i am happy now i am also pissed off because i dont know the bottom of it... I think i will remove all the wiring from that stupid aftermarket alarm because now i honestly have doubts that something is wrong with that!  Guys thanks for all the help and i will post some pics so you know it was worth fighting for  :smiley: :smiley: once again thanks!
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: dixie180 on 14 February 2013, 20:22
Hope the problems fixed m8.One word of caution tho,a faulty Crank Sensor will not always show up on VAGCOM.
 
Good Luck  :wink:
Rob
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 14 February 2013, 20:57
Thanks mate  i will get a new sensor just in case :wink:

Chris
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 21 February 2013, 19:48
And i am back  :laugh: Car pissed me of again!! Today it starts and cuts off after 2-3 seconds even if i give it throttle ?? What now ? Immobiliser?? Or something else ?
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Gavv8 on 21 February 2013, 19:49
Got petrol?. :laugh:
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 21 February 2013, 19:51
Haha i do ,filled up half tank yesterday.....
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: dixie180 on 21 February 2013, 20:01
I take it you fitted new crank sensor ???
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 21 February 2013, 20:05
No  :embarrassed:  but it was driving for 10 days now with no problems???
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: dixie180 on 21 February 2013, 20:11
Ok.I could be barking up the wrong tree but i would definitely get it changed mate.Like i said a VAGCOM may not always throw up a fault with the crank sensor.
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 21 February 2013, 20:15
I know embarrassed  now will change it asap .... Its confusing me because it was driving for days now with no problems and never cut out while driving.
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: dixie180 on 21 February 2013, 20:18
Just PM'd you bud. :wink:
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 02 March 2013, 19:11
Hahaha finaly i got it it was dodgy fuel pump relays !!! f**kin 3 of them ,i should play the lotto with the luck i have.... I started notecing that when they heat up and i turn the car off it wont start again so i started swapping them every time it happened and car started straight away with the cold relay.... It took me long time to figure it out because i was doing only short runs to work and back so it never heated properly...strange thing is that the relay was clicking and the voltage at the pump socket was correct but every time the relay was electricaly loaded with pump drowing  current from it it would fail  :laugh: :evil: Guys thanks for all the help specially Dixie hopefully it stays going  :wink:
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: dixie180 on 02 March 2013, 20:23
Nice one Kmad.Unfortunately my issue is back. :cry: :cry:
Title: Re: Mk3 gti 8v HELP PLEASE wont start something weird is going on
Post by: Kmad on 03 March 2013, 00:19
Whats up with yours?