My AHU no start

[ludowrx974]

hello !! my car no want start. The engine only start whit cleaner, if i turn off it's impossible start. I have already check:


- vagcom no code

- relay 109 it's ok

- Pump selenoid it's ok 12v on

- I tested a new pump (engine always no start)


- I tested all injector (engine always no start)


Sorry for my english !

 

[Mozambiquer]

Have you checked timing? How about compression? Both of those could cause issues.

Sent from my S60 using Tapatalk

 

[ludowrx974]

Have you checked timing? How about compression? Both of those could cause issues.

i ckecked the timing but i did not ajust the timing with VCDS but I don't think it prevents her from starting.

I not have tool for compression.

 

[ludowrx974]

i checked CKS sensor it's about 1.2k ohm

 

[Mongler98]

We mean physically checking timing marks. Not what's in vcds. Also there is no timing adjustment in vcds. Its manual.

There is a good thread here on no start.

You should not have a pump. Ahu only has IP. No in tank pump. So your getting fuel at each injector ?
Sounds like your wire harness is suspect. Check ALL of the wires in the cord to the ip. White wire especially. Typical for them to brake.

 

[ludowrx974]

We mean physically checking timing marks.

yes i used timing marks and use tool specific engine.


yes there are not pump in tank. and i have good fuel at each injector when the engine start.

when the egine start with cleaner i eliminate:


-The immoblizer
-ECU
-CKS sensor

 

[garciapiano]

A car that only starts with starter fluid would indicate an issue with fuel delivery. Crank no start condition usually indicates an issue with the shutoff solenoid and potentially the pump electric controls themselves.. In my car, crank no start was related to a bad ignition switch. I restored proper starting with bypassing the alarm module immobilizer, replacing the ignition switch and replacing relay 109.

Usually an issue with a connection to the shutoff solenoid will result in a code, so the fact that you are getting no codes leads me to think there is something else that is not triggering that solenoid to open.

 

[ludowrx974]

what do think the timing

 

[Mongler98]

You can have fuel delivery but not enough.
Check the wires on the harness. This is a growing issue now.

 

[ludowrx974]

i have already check on the harness just wire:


-shutoff selenoide. there are 12v and i even removed the piston small inside

-CKS sensor 1,2k ohm about

 

[Mongler98]

So it's a shot in the dark but check the connections at the 109 relay. I have a mk3 ahu like yours and I some times have to wiggle the 109 to start but once started it will run but needs to wiggle again to start. Not sure why but the relay is good but the connection at the block is worn out . Also had a very similar issue with the smaller ip harness wire connection. Pull it apart and make sure its clean.

 

[Steve Addy]

hello !! my car no want start. The engine only start whit cleaner, if i turn off it's impossible start. I have already check:


- vagcom no code

- relay 109 it's ok

- Pump selenoid it's ok 12v on

- I tested a new pump (engine always no start)


- I tested all injector (engine always no start)


Sorry for my english !

What happened before your engine quit running?

When was last time you replaced the fuel filter?

Is this 110 hp tdi?


Steve

 

[ludowrx974]

What happened before your engine quit running?


When was last time you replaced the fuel filter?


Is this 110 hp tdi?

Steve

Nothing, I am one morning I park afterwards to leave the engine don't want satart.


I finish change i replace by a new filter.



It's 90hp

 

[ludowrx974]

today i tested the pump in the tank. i used a pump to see if its sucked fuel well. I think this is good
what do you think !

 

[Steve Addy]

Ok, so you have a new fuel filter installed recently?

Does your car have the immobilizer? What year is your Cupra?

Steve

 

[ludowrx974]

Ok, so you have a new fuel filter installed recently?

Does your car have the immobilizer? What year is your Cupra?

Steve

Yes i replace the filter by a New. Its golf 3 ahu.
If its immobilizer you think its possible Shen same with a fluid start engine ?

 

[Mongler98]

You can jump the security immobilizer behind the dash driver side door dise vent.

 

[ludowrx974]

You can jump the security immobilizer behind the dash driver side door dise vent.

I don't have immobilizer at least I can't find it. may be the european car because not this type immobilizer.
on the other hand I more or less find the breakdown either it is ignition switch or connector.When i move the wire the engine start and sometines no start.
Somebody have a schematic ignition so that I can find the fault precisely.

 

[Mongler98]

All makes came with one. It's not under the steering colum. Lile I said. Pull off the side vent its behind that off to the side

 

[ludowrx974]

All makes came with one. It's not under the steering colum. Lile I said. Pull off the side vent its behind that off to the side

there is nothing

 

[Mongler98]

Sorry my bad. Behind the headlight switch.
See here
http://faculty.ccp.edu/faculty/dreed/Campingart/jettatech/alarmcentralhelp/alarmhelp2.htm

 

[ludowrx974]

Sorry but there is nothing behind headlight Switch

 

[Mongler98]

There has to be that harness and it will be either plugged into a bypass or just hanging there with the bypass already done.

 

[Steve Addy]

I don't have immobilizer at least I can't find it. may be the european car because not this type immobilizer.
on the other hand I more or less find the breakdown either it is ignition switch or connector.When i move the wire the engine start and sometines no start.
Somebody have a schematic ignition so that I can find the fault precisely.

Ok, are you talking about Leon or Ibiza? I have been assuming you have a Leon? Also what year is your car, it will help to know.

I am beginning to suspect that your ignition swith is bad, especially since you mentioned a wire that would cause it to start and then not to start.

When he says immobilizer he really means convenience module or alarm box. It controls keyless entry and sets off an horn if the car is broken into.

Steve