Lack of power, Engine Light on and cutting out Golf 1.8t

[Gabriel2202]

I have a bit of a weird one here that has me puzzled and I could really use a bit of help.

My Golf 1.8t (AUM) has recently starting cutting out and then won't start for a few minutes after - it will turn over but won't start and does this when both hot and cold. This has been happening for the last few days, even cutting out when doing a u-turn leaving me in the middle of the road! My missus also said that when she put her foot on the accelerator the other day the car actually slowed down? (no she didn't accidentally hit the brakes  )

The engine management light has come on, and I have scanned with vagcom which produces the following codes:

17939 - Camshshaft Timing Adjustment: Open Circuit
            P1531 - 35-10 - - - Intermittent
17840 - Secondary Air Injection Solenoid Valve (N112): Open Circuit
            P1432 - 35-10 - - - Intermittent
17695 - Boost Pressure Control Valve (N249): Open Circuit
            P1287 - 35-10 - - - Intermittent
17645 - Fuel Injector for Cylinder 1 (N30): Open Circuit
            P1237 - 35-10 - - - Intermittent
17647 - Fuel Injector for Cylinder 3 (N32): Open Circuit
            P1239 - 35-10 - - - Intermittent
17648 - Fuel Injector for Cylinder 4 (N33): Open Circuit
            P1240 - 35-10 - - - Intermittent
17646 - Fuel Injector for Cylinder 2 (N31): Open Circuit
            P1238 - 35-10 - - - Intermittent
17834 - EVAP Purge Valve (N80): Open Circuit
            P1426 - 35-10 - - - Intermittent
17956 - Boost Pressure Regulation Valve (N75): Open Circuit
            P1548 - 35-10 - - - Intermittent
17526 - Oxygen (Lambda) Sensor Heating: B1 S2: Open Circuit
            P1118 - 35-10 - - - Intermittent
17841 - Secondary Air Pump Relay (J299): Open Circuit
            P1433 - 35-10 - - - Intermittent
Readiness: 0010 1001


I had these codes before and fitting a new ignition switch cleared them but a few months later and they're back. The spark plugs, ignition switch, fuel relay and both lambda sensors have recently been changed. I thought it may be the crankshaft sensor after reading the thread a few posts down, but it happens when both hot and cold.

Anyone got any ideas of where to start? I really can't afford to throw too many parts at it, or pay a garage to look at it, so am at a loose end. Thanks

[james2]

God where do you start with that list, thank god i got a AGU  Sorry i can not help......

[Nino]

Sounds to me you have a harness issue here but, basically its saying that the connectors on the N75 valve, the connector thats connected to the cam shaft sensor located directly on the block (just under the where the AUM is stamped on the block) and the connectors on the fuel rail is not getting any power.

have your batt checked, make sure its pushing over 11.6 volts and that your alternator is also working as it should, It might also be a good idea to Ring VW and check if your car has been in since the AUM's had a recall for coil packs, if not get it in ASAP, they will replace the whole coil system free of charge.

Your problem defo seems power related to me, check relays, fuses, ensure your Injiction harness is not broken, or not plugged in tot he sensors correctly.

[Gabriel2202]

Sounds to me you have a harness issue here but, basically its saying that the connectors on the N75 valve, the connector thats connected to the cam shaft sensor located directly on the block (just under the where the AUM is stamped on the block) and the connectors on the fuel rail is not getting any power.

have your batt checked, make sure its pushing over 11.6 volts and that your alternator is also working as it should, It might also be a good idea to Ring VW and check if your car has been in since the AUM's had a recall for coil packs, if not get it in ASAP, they will replace the whole coil system free of charge.

Your problem defo seems power related to me, check relays, fuses, ensure your Injiction harness is not broken, or not plugged in tot he sensors correctly.

Thanks for your advice  , I have checked the battery and it's fine, I followed a guide on ukmkivs to check that and the alternator with a multi-meter and they were fine...

I'll have to go over my loom again and check for any splits or faults in the wiring. Are their any specific test I can do on the fuel injectors to check them? the N75 is only a few thousand miles old and the coil packs were checked by VW in August (they had all already been changed for aftermarket ones  )

[Nino]

Well its easy to check your harness is getting power, pope your multi meter on the pins, think its brown and white?

[Gabriel2202]

Well its easy to check your harness is getting power, pope your multi meter on the pins, think its brown and white?

Cheers, that's tomorrows task then, I'll let you know how I get on with it

[Gabriel2202]

So the loom is fine and getting power to everything it should be, but now my cars stuck in a car park! Seems to be worse when it's up to temp! At least when it's cold it will start after a few attempts....

I did notice a really high pitched noise coming from my throttle body, before I start to crank it and when the keys are in the ignition? It's an aum so has dbw. Any ideas anyone?

I'm going to put an LED in an injector connection to test the camshaft sensor as soon as I find them!

[Gabriel2202]

Went back to it this morning and it started first time cold? Gonna take a gamble at camshaft sensor

[Nino]

That high pitch sounds from the TB is it tryin to self allign itself, have you remived the TB for a clean recently? I only know this because i recently did a TB re-allignment using my vagcom.

I at this point to start looking at sensors, there will be one bolted into your inlet manifold just next to the TB, get it out and give it a good clean with some carb cleaner. Next I would replace your temp sensor its located on the right side of the block, i.e same side as the batt. It only cost around £8 to replace for a gen part, its worth replacing the C clip too only about 60p I cannot stress enough how important it is to only use gen parts on sensor do not buy cheap.

After that i would get your codes cleared and see how it goes, if the problem is still there the codes will cone back after about 5-6 drives.

Does your engine temp do strange things? I.e sit at 90 then go down to 70 when at lughts etc? If it does you will need to replace your therostat will cost about £30-40 for a gen part, again do not buy a cheap one get a gen.

All what i have said above will cause driving/starting issues mega cheap to fix and will make your mpg alot better too.

[Gabriel2202]

I figured it would be aligning itself, but when I do it on vagcom it's not as long as this. It's like 20 seconds everytime I move the ignition to the 'on' position. I changed my coolant temp sensor for an oem (febi) green one a few thousand miles ago, but have a spare so can try that. After work I'm going to clean the throttle body, and sensor with carb cleaner and realign with vagcom, see if that helps and if not then I have just had a camshaft sensor delivered from ECP so that's on standby but will fit it as a last resort as it cost me £70 (Bosch one) - still better than £120 from VW.

Will the sensor be alright to spray with carb cleaner? I heard the maf doesn't like it but is the TB sensor alright to clean?