Hi All,

I was hoping someone may be able to assist me.

My Dad has a T reg 1.3 multipoint Felicia. Today its starting to cut out on him. He has Skodas all the way from the S100 back in the 70's and loves them. He has no problems at all with this one from new, until now.

Seems to be when warm. either in traffic or whilst stopping at lights etc. The revs drop to approx 500rpm and then it cuts out. No other running issues at all. Engine temp is fine etc. Is there anything i can tak a look at and poss sort out for him? I am a Tech but have not any diagnostic equipment to hand.

Someone has mentioned (not on here) dirt build up in the throttle body or poss a crank position sensor.

If someone has come accross this before i would be most grateful for any assistance.

Cheers,

Clive.

Warm or hot?

If warm, check there's a little free play in the cable.

If hot, it's possible it could be the engine temp sensor, which has 2 outputs, one for the guage, and another for the EMS.

Yep I would go with dirt build up on throttle body. It's relatively easy to clean. While you're looking in there you can check the throttle cable operation as per above. I doubt it's the crank sensor as I think it would just cut out rather than have the revs drop.

Edited 28 January, 201115 yr by anewman

I had the exact same problem last year. Can induce a few changes of underwear!

It is definitely the throttle body, apparently the MPI changed to a common part with the Polo and this is the weak link.

I changed the plugs, the lamda sensor and anything else affordable with no joy, took it to a garage and he identified the problem on the diagnostics and cleaned it up.

Mine was quite far gone and is believed to be at least part of the cause of mine refusing to restart properly when warm. That and the valve clearances and the temp sensor!

However to fix this problem while it's actually running, clearing up the throttle body is the cheapest fix.

Yep I would go with dirt build up on throttle body. It's relatively easy to clean. While you're looking in there you can check the throttle cable operation as per above. I doubt it's the crank sensor as I think it would just cut out rather than have the revs drop.

Cheers for the replies, and my appolagies for not getting back sooner. Some how im not getting reply flags in my emails.

Right, i have taken off the throttle body and cleaned it out. It was fairly coked up. Now its sparkling like new. Allback together and its no longer cutting out and the rev's are not dropping either. Unfortunatley its quite the opposite. It seems to stick at around 2000 rpm. If you blip the pedal it will fall to idle at approx 850 rpm. There are no issues with air leaks etc as its all been re-sealed around the base. The throttle cable has a nice amount of free play. It was doing it originally from hot and cold.

I have also cleaned the air sensor in the inlet manifold as that was pretty clogged up. After the work was complete i disconnected the battery for a while hoping to reset everything, but alas this is now not the case.

Does anyone know if the throttle position needs reseting via the diagnostic equipment? or may it be possible that there may be some crud stuck on the spindle somewhere?

Cheers again people,

Clive.

Yes, it's most likely you need to reset the throttle body. If you can, try leaving the battery disconnected for ~24 hours - that worked for me - or else it should be very quick and simple to do with VCDS (see if there's someone on the forum VCDS users list near you). The other main reason for the revs 'sticking' like that on the way down is a leak in the exhaust manifold/downpipe (before the lambda sensor) that confuses the ECU into overfuelling, but the fact it's happened after cleaning the throttle body suggests it's a simple realignment needed.

Yes, it's most likely you need to reset the throttle body. If you can, try leaving the battery disconnected for ~24 hours - that worked for me - or else it should be very quick and simple to do with VCDS (see if there's someone on the forum VCDS users list near you). The other main reason for the revs 'sticking' like that on the way down is a leak in the exhaust manifold/downpipe (before the lambda sensor) that confuses the ECU into overfuelling, but the fact it's happened after cleaning the throttle body suggests it's a simple realignment needed.

Superb !! Cheers mate.

mmmm It sometimes can be a little slow to start when hot, i did suspect overfueling at one point. I will have a look around the downpipe area.

You mentioned VCDS users, is there a section on here where they are listed? We do have a skoda Specialist nearby, but i dont really want my Dad going there as the work that was done last time was shoddy. I had to rectify it twice.

Thanks mate, much appreciated.

There's a sticky thread in the Diagnostics & VCDS forum here. Failing that, any garage with VW-compatible diagnostic equipment should be able to do it in only a couple of minutes. I'm not sure of the exact sequence for the 1.3 but it's generally a pretty standard procedure (I may be able to find out but it means a lot of translating from Czech ). If it helps, it seems the same Simos 2P ECU was used in 1.0 Lupos with the AHT engine - since I imagine most garages will be more familiar with VWs than old Skodas, although I'd imagine the later Simos unit in the 1.4 Fabia is the same as well.

edit: it seems you might also be able to force adaptation by switching the ignition on and leaving it for ~30 seconds. Worth a try anyway, since it's free!

Edited 29 January, 201115 yr by RobinSLXi

There's a sticky thread in the Diagnostics & VCDS forum here. Failing that, any garage with VW-compatible diagnostic equipment should be able to do it in only a couple of minutes. I'm not sure of the exact sequence for the 1.3 but it's generally a pretty standard procedure (I may be able to find out but it means a lot of translating from Czech ). If it helps, it seems the same Simos 2P ECU was used in 1.0 Lupos with the AHT engine - since I imagine most garages will be more familiar with VWs than old Skodas, although I'd imagine the later Simos unit in the 1.4 Fabia is the same as well.

edit: it seems you might also be able to force adaptation by switching the ignition on and leaving it for ~30 seconds. Worth a try anyway, since it's free!

NIce one mate, thanks very much for the info. I will try the ignition thing tomorrow and go from there. We have found somewhere nearby that could do it if not successful.

All i have is a code reader, and thats not going to do it i dont think.

Cheers again mate, very much appreciated.