Warm start issue on 1.6FSI(BAD).....literally....

mjdavie11

Member
Hi everyone, having a warm start issue on my A2, run a quick scan and found the attached. I am under the impression that I need to change the Camshaft Position sensor? If so, where does it live on the car?
1C29BCBA-D11F-42AF-9CB8-87B01DDEA8A4.jpeg


As ever, your thoughts greatly appreciated :)
 
Hi everyone, having a warm start issue on my A2, run a quick scan and found the attached. I am under the impression that I need to change the Camshaft Position sensor? If so, where does it live on the car?View attachment 46224

As ever, your thoughts greatly appreciated :)
I am confused, you say 'Camshaft Position Sensor' yet the VCDS screen refers to 'Manifold/Barometric Pressure Sensor'. If latter try item 30 in

https://audi.7zap.com/en/rdw/audi+a2/a2/2003-248/1/133-133005/#30

Andy
 
I am confused, you say 'Camshaft Position Sensor' yet the VCDS screen refers to 'Manifold/Barometric Pressure Sensor'. If latter try item 30 in

https://audi.7zap.com/en/rdw/audi+a2/a2/2003-248/1/133-133005/#30

Andy

I am referring to the two fault codes beneath. No idea if the other one maybe attributing to it but warm start issues found elsewhere tend to point toward CMP sensor. Incidentally, the manifold barometric pressure sensor g71 f96 seems to point to a suspect MAF unit


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Hi,

I see you have no further replies, I am not surprised after an exhaustive search on here and Google I can find very little and certainly nothing for the FSI BAD. Surprisingly the best I could find was for a 1.2TDI, if this is the same/vaguely the same/completely different for the BAD engine I have no idea but I would have thought in the same ball park.

https://www.a2oc.net/community/index.php?threads/1-2-tdi-camshaft-position-sensor-g40.32581/

Looks horrible access, good luck.

Andy
 
Thank you Andrew, I was really dreading this after not being able to find much myself. HOWEVER, after venturing outside and taking the lid of the mini-beast, it was staring me straight in the face! Amazing to think every time I was to clean out an air intake filter I have to take the bottom of the car off but this thing is right there (circled in red). Ordered one and hopefully this should go along way to curing those warm start issues.

70C5F633-6274-4B0A-BE05-2B6AC291A8CC.jpeg
 
Wow! My wife’s smart required the Engine to be dropped out of the car after removing most of the rear end to get to the MAF sensor - about 4.5hours of Labour, and £175 sensor to boot.


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Wow! My wife’s smart required the Engine to be dropped out of the car after removing most of the rear end to get to the MAF sensor - about 4.5hours of Labour, and £175 sensor to boot.


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Mercedes build again same as old A class
Lower engine to change starter???
 
Pretty much drop Engine to do anything. A turbo and an air con compressor system rammed into the engine bay along with the block and all ancillaries means there’s not much in the way of access with the engine in place. Basic service is just about okay, anything else is a dropped engine!

Luckily, I know a guy! Only Smart car indie in Scotland and is a legend. Sensor from OEM for £65 and did it in 3.5hours.


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6 months on I am still having this weird warm-start issue where it tries to start first time when warm but just doesn’t! Any ideas?
 
Did you change the Maf? It is connected to ignition parameters within the ecu and if putting out the wrong signal may cause a non start?
If you suspect Maf, you could try disconnecting the wiring plug and clean out the pins and retry, this does help as they can be corroded seen this before on other Audis, if you clean them at least it rules that out.

Looking at this from purely from a logical point, leaving out the different sensor names,i've not studied them as i haven't had the need yet, Love our FSI, but this points to some sort of Ignition or fuel fault. In a few of the cars i've owned over the years i've had this random hot start suddenly rear it's head but it quickly became inoperable which turned out to be a Hall sensor thats triggers of the rear of a cam on a Audi 2.6 V6 abc lump. I'd rule that out for now as yours is still starting.

Had this problem as well on an Audi - there must be an ignition amplifier output stage or similar that receives low output volts from the ecu in order to fire up the engine which converts to high output volts for each individual coil. The pcb tracks can distort and crack through heat soak causing erratic hot starting,If you follow my logic? If you can determine where that part is on the car that's where i would look, if only to eradicate that potential problem.Are your coils original, they could be breaking down now?

It could also be faulty wiring in the coil loom? Worth checking that out to ensure no breaks in the wiring and connectors are in good shape.Hth for now.
 
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MAF still the same unit, I tried just cleaning the contacts but didn’t think the plug needed disassembly. How easy is it to take the pins out the plug and inspect? Engine is lacking in uumph when running but idles smoothly with no misfiring so I have discounted coil/lead based issues. Reading up, there seems to be some consensus toward a temp sensor but that seems to be paired with starter motor not engaging (which does seem to be happening ok)
 
Warm start issues usually can be put down to 2 things........1, Fuel evaporation in the supply system causing vapour locks.......2, Bad electrical connection/Bad earth connection, which can give the ECU false information and result in incorrect timing/false MAF readings amongst other things.
I would suggest checking all the earth connections between the chassis and engine, as a first no cost operation make sure they are all clean don't just visually inspect them take them apart and clean all mating surfaces, then check/clean all the electrical connections in the engine bay, a high resistance in a connection can cause problems also.
Next clear the fault codes and drive the car rescan and see what shows up, if clear YIPEE,................... if not dig deeper into the codes shown.
The fuel system is a little more complex and unless your happy playing with a source of potential fire/burnt out car leave it to an expert........but if you're happy to test the system you can check pump supply and the high pressure supply as a first base.
One thing I will say is be methodical and don't change stuff without a good reason, you could put more faults in the system.
 
Ok, just replaced the MAF as indicated in a previous scan and checked the condition of the pins and cleaned just to make sure. Cleared codes, Started car and switched off again and the top issue still persists! I have a sneaking suspicion that it maybe something to do with vapour locks in fuel line (I attacked the front earthing point down by the headlight cluster and removed trim in driver side footwell and gave those two leads the same treatment but they looked like new!
 

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The earth cable from starter to chassis behind the headlight might look OK though mine effectively broke off where the crimp ends. The heat shrink was holding water assisting corrosion.
 
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