High hydrocarbons

[lanciamatt]

I'm putting this out there. I've got a dedra turbo that has very high hydro carbons, CO is fine. Checked compressions they are OK, it runs fine. But it won't idle when cold. I've cleaned out idle control valve and swapped it to no avail. If ign on and you plug idle valve in it pulses but nothing happens when it's running, I'm thinking this could be something to do with it?

[sierraman]

I don’t know a great deal about lancias but does it use more oil than it should? I know they use a bit of oil but is it smoking or leaking it past the valve stems? The idle and the (presuming) test fail on excessive hydrocarbons might not be related.

[pilninggas]

Duff plugs and leads?

[lanciamatt]

All service parts changed, doesn't really use oil no smoke, boosts good

[M'coli]

Temperature sendor dodgy? It won't idle when cold, and over-reads when warm might be due to the ECU using a default value that pleases neither.

Can you find a way to spray petrol or suchlike into it on idle when cold, to mimic enrichment?

Other than that it could be shonky injector spray pattern.

[pilninggas]

All service parts changed, doesn't really use oil no smoke, boosts good

do the sparks look good?

[richardthestag]

when I had unexpectedly high hydrocarbons but everything else was ok it was down to a lean fuel mixture.

 

This was caused by a shit reproduction air filter that was so dense that air couldnt easily get through it.

 

took a while to id the root cause. 

[Squire_Dawson]

What is your driving style? Would an Italian tune-up work I wonder.

[M'coli]

Can we go back a bit, please? Let's establish what year the Dedra is, and what injection system it has.

1. What's the injection system?

2. What's the ignition system?

3. As in, who makes them both?

4. Does it have a lambda or cat?

5. What codes is it flashing up, if any?

 

I have a Haynes BOL on pre-OBD ECUs if it helps.

[lanciamatt]

It's multipoint made by webber and magneti marelli. It's pre cat no lambda and no managment light

[lanciamatt]

I think ive solved the idle issue when cold. When ign on engine off there is 12v to idle valve, when engine running it looses the 12v.i power probed the wire with 12v and hey presto it started working. I managed to get a wiring diagram and the fuel pump relay has a 2nd 87 pin, this is the output for the idle valve. I had a route round in garage and found a 5 pin relay, popped it in and now working. Will try it again in morning when cold. It looks like the system has a 12v constant feed and the ecu uses PWM signal on the earth side to control it

[tul66]

Well done! Not a fan of Dedras though.

[Uncle Jimmy]

The Fiat twin cam is a dirty bugger and likes a drop of oil, sounds like you're on the right track with pcp valve/over fueling.

[lanciamatt]

I know what you mean with dedras, it's not lancias finest hour. They are nice to drive, handle like go carts and its quick