no codes displayed car will not start

[mr rugby]

Hi gang,
vag-com free version with 3rd party lead.
mk4 polo 1.4 auto 8v auto 1999.
intermittant problem
engine turns but will not start.
next day engine fires ok and runs fine, if I then switch off it may not start again or it may.
engine turns over but does not fire.
I have a spark at the leads.
vag-com shows no faults
any ideas
cheers
mr rugby

[kenney]

Hi The symptoms are typical of a faulty current supply relay

[steve555]

Hi The symptoms are typical of a faulty current supply relay


hello I have an audi a4 1995 with a simliar fault at the moment

The car turns over but will now not fire up

Prevoiusly car was turning over and then fireing up/ starting for 2 seconds and then cutting out. So I thought it may be a key / immobiliser fault

Vagcom Locksmith engineer has checked keys and the reader coils and they are both fine- the car recoginses the keys as correct- but car will still not start after turning over ( execept for one or two exceptions when it will start/ fire up and then cuts out after two seconds)

There is an audible alarm in the engine compartment- one long whining noise coming from one of the metal casings housing electiics in the engine compartmanet ( ( directly opposite the passenger side light ))-

Im wondering whether this has anything to do with the same starting fault -?? as I bever heard the alram before in over 10 years of owning the car. Is this something to do with the Current SUPPLY Relay circuit?? - is this a big job to sort out-

Really desperate to find out the fault so any help appreciated

thanks
Steve

[steve555]

Hi forgot to add that the car has had an A4 new reader coil fitted 3 years ago - so audi advised its very rare for reader couils to go twice

[kenney]

Hi Steve Normally when there is an issue with the immobilizer the engine will start and then stop again after 3-4secs.An aftermarket fitted alarm can cause various faults among other things start problems,depending what it is wired up to.Regarding the current supply relay ,without having to measure the wiring etc etc just replace the relay its not an expensive part.Have you had a fault code read?but there again an intermittent fault with the relay will no show up on a diagnose.

[steve555]

Hi Steve Normally when there is an issue with the immobilizer the engine will start and then stop again after 3-4secs.An aftermarket fitted alarm can cause various faults among other things start problems,depending what it is wired up to.Regarding the current supply relay ,without having to measure the wiring etc etc just replace the relay its not an expensive part.Have you had a fault code read?but there again an intermittent fault with the relay will no show up on a diagnose.

thanks kenny

The VAGCOM engineer did not pick up any fault codes - when he checked the car out

Also no after market alram fitted. From what you say if it is the imobbilser then that sounds very expensive - thecar can only be woth 500 pounds ( when working ) so its not looking at all good. really worrying now

any suggestions as to what else I can do ?????

thnaks

steve

[kenney]

Hi (The car turns over but will now not fire up) THIS IS NOT THE SYMPTOMS OF THE IMMO (Prevoiusly car was turning over and then fireing up/ starting for 2 seconds and then cutting out. So I thought it may be a key / immobiliser fault.)BUT THIS IS. Lets start with the basics,can you hear the fuel pump start and stop each time you turn the ignition on and off?Have you checked if you have a spark at the plugs

[steve555]

Hi (The car turns over but will now not fire up) THIS IS NOT THE SYMPTOMS OF THE IMMO (Prevoiusly car was turning over and then fireing up/ starting for 2 seconds and then cutting out. So I thought it may be a key / immobiliser fault.)BUT THIS IS. Lets start with the basics,can you hear the fuel pump start and stop each time you turn the ignition on and off?Have you checked if you have a spark at the plugs

thanks kenney
The spark plugs were checked by the aa man - he said they were fine - the aa man took over an hour cehcking them and the other basics before giving up

I think the fuel pump does switch on as can hear a swith in the engine compartments clicking when i turn the key

waht is reaklly frusrtaing is that yesterday charged the battery, tried the key and the engine started and remained on !! I thought it may be the spare key but when In turned the engine off an tried with the same key the car refused to fire up . the vagcom man then turned up and no more succecssful starts

now the car wont even fire up for two seconds it just turns over ( last time it fired was once this mornng)

[kenney]

What is your engine code?

[steve555]

What is your engine code?


the vagcom man said it was 0687- thats the pin code

is this what you mean its an audi a4 1.6 litre engine?

[kenney]

Hi You have an ADP engine 1.6 Bosch Motronic.The fault could be a number of things and I cant advise you other than,get someone who knows what they are doing to check it.But as i said in the first post there is a possibility it is the current relay thats playing up.

[Crasher]

Assuming the Polo at the beginning has an AEX engine and a CMJ box and is a 6N1 Polo, then that does not have an ECU relay.

The ADP engine doesn’t have the classic ECU relay either, it has a combined ECU and fuel pump relay with 208 printed on top which is now replaced by relay 372 and is VAG part number 4D0 951 253 costing £20.95 from Audi.

[mr rugby]

Hi The symptoms are typical of a faulty current supply relay

Hi kenney,
current supply relay ??
where
what
how.

Cheers

mr rugby

[Crasher]

Ahh Mr Rugby, can we have some more details of your car. PM me the reg or chassis number if possible.

[mr rugby]

Assuming the Polo at the beginning has an AEX engine and a CMJ box and is a 6N1 Polo, then that does not have an ECU relay.

The ADP engine doesn’t have the classic ECU relay either, it has a combined ECU and fuel pump relay with 208 printed on top which is now replaced by relay 372 and is VAG part number 4D0 951 253 costing £20.95 from Audi.

Thanks for your reply,
How do I go about identifying the engine type etc quoted above.
Are they stamped on the engine or on id plates, also where is the fuel pump relay is it in, fuse box,engine bay !!!!

Thanks for your help

mr rugby

[steve555]

Assuming the Polo at the beginning has an AEX engine and a CMJ box and is a 6N1 Polo, then that does not have an ECU relay.

The ADP engine doesn’t have the classic ECU relay either, it has a combined ECU and fuel pump relay with 208 printed on top which is now replaced by relay 372 and is VAG part number 4D0 951 253 costing £20.95 from Audi.


thanks would this explain the whining alarm noise from the engine bay that reamins on for about a minute when I try and start the engine

I assume that the alarm means something elcetrical is not quite right

thanks steve

[mr rugby]

Ahh Mr Rugby, can we have some more details of your car. PM me the reg or chassis number if possible.

crasher,
I have sent you a pm

thanks

mr rugby

[steve555]

Hi You have an ADP engine 1.6 Bosch Motronic.The fault could be a number of things and I cant advise you other than,get someone who knows what they are doing to check it.But as i said in the first post there is a possibility it is the current relay thats playing up.


hi kenny just been told by the driver that when the RAC/AA man came to look at the car he did check that there was fuel going intio nthe engine and confirmed that this was the case- abd so I can confirm that bthe fuel is going into the engine


really is a mystrey this one- many thanks for you ongoing advice on this its really appreciated

any other thoughts?

steve

steve

[Crasher]

Mr Ruby, your car has an APQ engine and a CMJ box and is a Polo 6N10F3. It has no ECU relay and is powered from fuse 2 with a permanent supply and an ignition live command feed from the ignition switch that isn’t fused.

[kenney]

[quote=mr rugby;147034]Hi kenney,
current supply relay ??
where
what
how.

Hi Very very sorry about that Mr Rugby i made a mistake as Crasher says there is no relay on this engine.(Just making sure Crasher was on the ball)Ha Ha

[mr rugby]

Mr Ruby, your car has an APQ engine and a CMJ box and is a Polo 6N10F3. It has no ECU relay and is powered from fuse 2 with a permanent supply and an ignition live command feed from the ignition switch that isn’t fused.

Thanks crasher,
Now that I am armed with that info, could you throw any light on why my car will start normally one minute, then if I turn off the engine and restart, say, five minutes later all it does is turn over.
How can immobilisers be checked ?

Thankyou matey,

mr rugby

[Crasher]

I would suspect the distributor hall sender, especially if it is a Marelli unit. The best solution is to replace the complete distributor with part number 030 905 237 CX which costs £84.60 inc. VAT from VW for a genuine exchange unit. You could replace the hall sender IF the distributor is a Bosch unit but they are £59.14 inc. VAT alone. You may pick up a non genuine distributor cheaper elsewhere but they will not have a two year warranty. A new distributor has to be set using diagnostic equipment to put the ECU into Basic Adjustment mode.

[steve555]

I would suspect the distributor hall sender, especially if it is a Marelli unit. The best solution is to replace the complete distributor with part number 030 905 237 CX which costs £84.60 inc. VAT from VW for a genuine exchange unit. You could replace the hall sender IF the distributor is a Bosch unit but they are £59.14 inc. VAT alone. You may pick up a non genuine distributor cheaper elsewhere but they will not have a two year warranty. A new distributor has to be set using diagnostic equipment to put the ECU into Basic Adjustment mode.

hello crasher

can you tell me where in the car i would find the ecu on a 1995 Audi A4 as i have a simialr problem.

the auto ecelctrician needs to know if i have a bosch or hitachi unit
and i need to find the part number.

ps( the audible alarm is no longer going off now from the engine bay so havent managed to precisely locate it)

one further thought is that the car has had a damp footwell on the drivers side for a number of years- not excesive just damp

thnaks for your help

[Crasher]

In the black casing under the windscreen, it will be Bosch as far as I know on an ADP engine.

[speed1e]

hello all just registered today

if you have a spark and you know fuel is getting there i would check the inhibitor switch (not sure of spelling but the switch on your auto gearbox that stops car from starting when in gear) try by passing it by turning you key on and put a feed from battery positive direct to solenoid on the starter via a length of spare cable if starts look for any adjustment on the inhibitor switch.

only hold feed on a short while though dont bolt it on!! and watch for the pullies etc

i had a similar problem on my sharan and new switch fitted and adjusted easy fix even for me

hope this helps wont cost you anything to try it no parts needed

cheers speed1e ;)

[steve555]

hello all just registered today

if you have a spark and you know fuel is getting there i would check the inhibitor switch (not sure of spelling but the switch on your auto gearbox that stops car from starting when in gear) try by passing it by turning you key on and put a feed from battery positive direct to solenoid on the starter via a length of spare cable if starts look for any adjustment on the inhibitor switch.

only hold feed on a short while though dont bolt it on!! and watch for the pullies etc

i had a similar problem on my sharan and new switch fitted and adjusted easy fix even for me

hope this helps wont cost you anything to try it no parts needed

cheers speed1e ;)

THNAKS speedie

by auto gearbox do you mean automatic as the audi is a manual gerabox - or is it just called autogearbox

thnaks
steve

[speed1e]

sorry mate i thought i had read that it was an automatic my mistake

speed1e :confused:

[labarnes]

Hi all

Is there any way to link threads? This thread is almost identical to the issues I'm having on my 1995 Audi A4 1.8. I even get the same alarm/buzzing noise that lasts for about 2 mins after connecting the battery...

My thread is: http://www.vwaudiforum.co.uk/forum/showthread.php?t=30729

Can someone tell me where the inhibitor switch is, if an A4 (manual gearbox) has one...?

I was trying to find a way to bypass the immoboliser. At least so that I can drive it to the Audi dealer. I'm worried that if resetting/recoding doesn't work, I'll have to pay lots more, as I won't be able to drive it home. Audi will probably try to charge me storage costs as well...

[Crasher]

The buzzing is the throttle body and they do this with the ignition on.

Manuals do not have a starter inhibitor switch.

[mr rugby]

Mr Ruby, your car has an APQ engine and a CMJ box and is a Polo 6N10F3. It has no ECU relay and is powered from fuse 2 with a permanent supply and an ignition live command feed from the ignition switch that isn’t fused.

UPDATE
Took car to a vw specialist, checked spark.fuel and compression which were ok.
He then carried out a full "basic settings" reset with vag-com and now is all well again.
It turned out to be a throttle issue that required a full reset.

Thanks to all that advised.

mr rugby

[vr6280]

COILPACK???

I had this on 2 golf's in the past. Usually about £50-60 from GSF

Aparently a very common VAG fault. take 5 mins to change on a Golf GTI so would image it wouldn't be too hard to do

[ali_b]

i had same problem! same symptons turning over ok but wouldnt allways start thought it was imobiliser.....
turned out to be the battery wasnt holding a good charge...after a long run would start ok for a few days then failed to start (but still enough power to spin engine for 7-8attempts).

worth a try most place's check em for free under heavy loads, cost me £45 for a new one and starts first time every time now!

[dub-a3]

Hi guys, i have a a3 1.8t on an r plate (AGU engine code)

My car has recentley had problems starting (only in the morning when its cold - soon as its been running for a bit its fine).

I have noticed that when i turn my ignition on before starting there is a strange buzzing coming from what seems to be my TB? - not too sure on exact position though as it was dark this morning when i checked.

This is usually what happens when i go to start her,

First attempt - usually just a click (no turn at all)

2nd attempt - maybe 1 or 2 turns

- this usually progresses until finally it starts after 5 or 6 attempts.

It also will only start once this electrical buzz has stopped.

Could this be a relay fault? would prob make sense to me if it was.

Any help would be much apriciated!!:biglaugh:

[highline les]

alright bud i had the same prob on my mk3 golf it turned out to be a relay

hope it helps

[Crasher]

Hi guys, i have a a3 1.8t on an r plate (AGU engine code)

My car has recentley had problems starting (only in the morning when its cold - soon as its been running for a bit its fine).

I have noticed that when i turn my ignition on before starting there is a strange buzzing coming from what seems to be my TB? - not too sure on exact position though as it was dark this morning when i checked.

This is usually what happens when i go to start her,

First attempt - usually just a click (no turn at all)

2nd attempt - maybe 1 or 2 turns

- this usually progresses until finally it starts after 5 or 6 attempts.

It also will only start once this electrical buzz has stopped.

Could this be a relay fault? would prob make sense to me if it was.

Any help would be much apriciated!!:biglaugh:

The throttle body should buzz but it may need removing, cleaning and readapting to the ECU. I think a fault code read and throttle body clean by a garage that knows how to do this will show what is causing the staring problem.