Car idles perfectly at 900rpm.
Can maintain 40mph with just the odd hesitation.
Can occasionally do a flat out run in 2nd gear with a couple of stutters.

But in the main it's undriveable - stutters and hesitates badly, as in tear engine mounts out bad.

Changed HT leads no difference.
Bypassed Fuel Filter no difference.

Current suspect is dirt in the fuel line. We let the fuel tank run a bit low (I put 60l in it!?) and I put a bottle of STP fuel cleaner in too. 50 miles later symptoms started.

Does this ring any bells?

cheers for reading.
doddy

 

unplug your narrow range tps and go for a drive to at least eliminate that culprit, but it really does sound like there's a fairly serious blockage / problem with the fuel line / injectors.

 

sounds like mine, for me it was the tps

 

so you reckon a faulty TPS momentarily signals that the throttle is closed and ECU fuels accordingly i.e. just enough for idle?

 

a faulty tps typically tells the ecu the throttle has been shut, the ecu recognises that the revs are above idle, and totally shuts off the injectors, causing massive stutters.

 

cheers cobber - this all sounds right, because I don't think dirt in the fuel line could stop the whole motor - maybe just one or two injectors seperately but not the whole thing.

So an intermittent fault with one of the TPSs is a good guess - will the motor run with both disconnected, with either disconnected or just with Narrow disconnected?

cheers,
dod

 

You guys talk about a narow angle TPS. Are there 2 TPS on a TII? I'm having very similar problems...replaced the only TPS I knew of, didn't fix it. Can you tell me where the 2nd should be located if there is supposed to be one?

 

S5 models have 2 TPS's

 

doddy: I've unplugged the narrow range on my s4 and the car drives nicer. Others have been heard say that some cars don't run like this, but you can only try and find out Am fairly sure the s5 would also run 'fine' without them plugged in, but it's not a good idea to do for very long as the ecu is just guessing how much oil to inject, and not doing it accurately. Should be ok for testing purposes though.

 

First off, sorry for the delay in my reply - dad sent the car to RoTechniks in the end and meanwhile I've had enough bother with my Charade Turbo rebuild!

So Blowtus you were spot on - dodgy TPS (I pretty sure only one). Replacing that and installing a set of Magnecor leads did the job nicely.