850 T5 won't idle or rev

**thunderace** · Sunday 20th July 2014, 10:38

Help please..

Brief description of events.

Driving to work, accelerate out of bend, muffled pop and engine dies.
Try to restart turns over ok but won't fire.
Immediate thoughts are fuel and boost pipe.
After putting fuel in car, it fires but won't idle without throttle
and won't rev above 3000.
Anyhow get car home, can't get it over 30mph.
Check hoses and find one from hard pipe over block to i/c is loose.
Reseat and tighten, check others and try to start car.
Won't idle, revs ok but very rough.

Has anyone any ideas as car is needed for work etc

Thanks guys.

**WOODY T5** · Sunday 20th July 2014, 10:41

Knock sensor maybe

**WOODY T5** · Sunday 20th July 2014, 10:42

Or throttle switch

**oblark** · Sunday 20th July 2014, 12:53

Air leak,

If it`s a small leak the engine will idle high or if a big leak it won`t start or if it does it will run rough.

**thunderace** · Tuesday 22nd July 2014, 13:10

Thanks for the replies, leaving the engine to idle lumpily on its own for a few minutes it settled down and it was possible to rev it, albeit running a little rough. Upon looking further I found bottom hose from the intercooler had also popped off.

Funny thing once this was reconnected the car would not run at all. Started and immediately dies. So I disconnected the top hose to the i/c and it started and idles steadily at normal 1000rpm. Reconnect the top hose and it died immediately. Now I am even more puzzled. It seems as if the i/c is blocked in some way.

Any ideas?

**MoleT-5R** · Tuesday 22nd July 2014, 13:25

Originally Posted by thunderace

Thanks for the replies, leaving the engine to idle lumpily on its own for a few minutes it settled down and it was possible to rev it, albeit running a little rough. Upon looking further I found bottom hose from the intercooler had also popped off.

Funny thing once this was reconnected the car would not run at all. Started and immediately dies. So I disconnected the top hose to the i/c and it started and idles steadily at normal 1000rpm. Reconnect the top hose and it died immediately. Now I am even more puzzled. It seems as if the i/c is blocked in some way.

Any ideas?

have you tried disconnecting the icv plug but with the pipes on ??

**thunderace** · Tuesday 22nd July 2014, 13:45

Originally Posted by MoleT-5R

have you tried disconnecting the icv plug but with the pipes on ??

no, what & where is it?

**thunderace** · Tuesday 5th August 2014, 09:52

Update.....Thanks for your input. Tried everything, even the RAC, who said it was probably a fuel sensor. That's
after plugging in their diagnostic equipment and telling me there was a problem with my electronic throttle! (It's an 850)

Long story short, eventually got relayed to Tim's and he sorted it with a replacement ECU. Simple.

**JamesT5** · Tuesday 5th August 2014, 10:33

Originally Posted by thunderace

Thanks for the replies, leaving the engine to idle lumpily on its own for a few minutes it settled down and it was possible to rev it, albeit running a little rough. Upon looking further I found bottom hose from the intercooler had also popped off.

Funny thing once this was reconnected the car would not run at all. Started and immediately dies. So I disconnected the top hose to the i/c and it started and idles steadily at normal 1000rpm. Reconnect the top hose and it died immediately. Now I am even more puzzled. It seems as if the i/c is blocked in some way.

Any ideas?

This sounds quite similar to my T5 rough idle issue, I'll be interested to see what you come up with. Mine splutters on start-up, a few revs and then it settles down.

**oblark** · Tuesday 5th August 2014, 11:58

Originally Posted by thunderace

Update.....Thanks for your input. Tried everything, even the RAC, who said it was probably a fuel sensor. That's
after plugging in their diagnostic equipment and telling me there was a problem with my electronic throttle! (It's an 850)

Long story short, eventually got relayed to Tim's and he sorted it with a replacement ECU. Simple.

The 850 has a throttle position switch which is what he is calling "electronic throttle"