Missing when cold

[PJMS_Polo_GTi]

I am not sure if the problem I had with my 2015 Polo GTi is the same as yours. About a year after my Polo GTi was delivered, I had a cold start problem. When I initially drove up the road and gave it a slight squeeze on the throttle, I would get a huge hesitation. I took it to my dealer who found nothing wrong. I asked them to keep the car overnight and try it again. I went back the next day and again they told me they found no problem. I took the car home. Next day I started the car and drove off. It seemed to have been cured. The only thing the dealer told me was as part of the service they tightened all the pipes around the turbo. I wasn't sure whether to believe that was the cure - however, it may be worth a check. The problem did come back, but not as severe, but I decided to drive the car much more gently and wait at least a hundred meters before trying to accelerate much (still only a slight squeeze on the throttle - I live in a 40 kph area!). I have not experienced anymore problems since adopting this regime of cold start driving.

[h100vw]

Did I not send you the vcds lite Dunc?

[sambb]

Mate I'd send you a clean flowed set of stock injectors to try out (to see if yours are fouled) but someone took them and ran!!

[PoloGIT]

Did I not send you the vcds lite Dunc?

Hey Gav, I do have, just haven't checked those blocks yet, tried to just now but laptop went flat, so will do so tomorrow hopefully.

[PoloGIT]

Mate I'd send you a clean flowed set of stock injectors to try out (to see if yours are fouled) but someone took them and ran!!

Bastards. Some people, honestly.

Gave the throttle body a clean out, as best I could without taking it off at least, but no dice.

Been a bit distracted today installing those B12s... In between buying Datsun parts and pretending to be a good father

[PoloGIT]

I am not sure if the problem I had with my 2015 Polo GTi is the same as yours. About a year after my Polo GTi was delivered, I had a cold start problem. When I initially drove up the road and gave it a slight squeeze on the throttle, I would get a huge hesitation. I took it to my dealer who found nothing wrong. I asked them to keep the car overnight and try it again. I went back the next day and again they told me they found no problem. I took the car home. Next day I started the car and drove off. It seemed to have been cured. The only thing the dealer told me was as part of the service they tightened all the pipes around the turbo. I wasn't sure whether to believe that was the cure - however, it may be worth a check. The problem did come back, but not as severe, but I decided to drive the car much more gently and wait at least a hundred meters before trying to accelerate much (still only a slight squeeze on the throttle - I live in a 40 kph area!). I have not experienced anymore problems since adopting this regime of cold start driving.

Thanks, that's certainly something to consider.

[PoloGIT]

If you can go to engine/measuring blocks/look at block 031 and 032. There will be a field called STFT/short term fuel trim/or additive STFT. It varies in different versions what its actually called. When the car us well up to temp and has been running around for a while, idle it, look at that block and the % should be less than +-3%. Much more than that and you have a vacuum leak.
If you delete the SAI you'll have to plug off the airbox hole. Follow the vacuum pipe from the combi diaphragm which will lead to the SAI solenoid. You can turf the SAI vacuum pipes and the bigger pipes but you'll need to either leave the solenoid plugged in or resister out that part of the loom. Despite the SAI being ticked off in the tune, that just means the second cat sensor isn't looking for a lean condition. However at the solenoid, the ECU still needs to see a complete circuit there. If not, for some reason your closed loop fuel trim adaptations wont work. It'll never go into closed loop. So easiest is in the meantime to leave the sai solenoid plugged in while you rationalise all its pipework, and then attack it with a resister later.

Pretty sure VCDS Lite only gives us the first 20 or 25 measuring blocks, doesn't it?

I used to have a hacked full version with the last Polo but not sure that still works, or the cable died or something. Guess i better stop being so tight and fork out for it.

[PoloGIT]

Hey guys, so finally got around to checking 31 and 32 measuring blocks...they say "Lambda xxx" with figures at 0.something. Have I got the right ones here?

It's still often running like balls when cold, and sometimes bad when not entirely cold too. For what it's worth, I've got a bottle of injector cleaner in the tank ATM...probably about 2 thirds through that tank now and not seen any improvement thus far.

[sambb]

first things first, is the air filter clean? I'm not being a **** in saying that. Mine was cold starting horribly recently. I've recently moved my pod to draw directly off the cold air feed that takes air from over the radiator. Because its right at the front of the car the filter gets really dirty really quickly. I hadn't anticipated that the intervals would change that much. I'd swapped in another set of coils, looked at mixtures, checked the o2 sensor bung was tight and looked for air leaks etc . Found that the filter was filthy, blew it out and problem never came back!

[PoloGIT]

first things first, is the air filter clean? I'm not being a **** in saying that. Mine was cold starting horribly recently. I've recently moved my pod to draw directly off the cold air feed that takes air from over the radiator. Because its right at the front of the car the filter gets really dirty really quickly. I hadn't anticipated that the intervals would change that much. I'd swapped in another set of coils, looked at mixtures, checked the o2 sensor bung was tight and looked for air leaks etc . Found that the filter was filthy, blew it out and problem never came back!

Interesting... Yes, I'll check that out. I guess it's about a year/10k+ ago that I swapped in a new filter, and also installed the PD160 and de-flapped the intake, so you might well be into something Will report back, cheers.