Thema 16vTurbo Engine Management- help!

[Leon Fletcher]

Hi all,

I have a UK Series 3 (K plate - 1993) Lancia Thema 16v Turbo LS. The "fuel injector" light stays on when the engine is started for some seconds (is this normal?), but then after a bit of driving, comes on. This seems to limit the car to "no-turbo" and about 100mph. The only way to make the light go out (and turning off the engine and restarting won't do it) is to drive (NOT rev) the car for a few seconds at about 5,500 rpm. When the revs drop when I change up, the light goes off.

Could there be a throttle position/rpm sensor malfunctioning? I have (of course!!) checked all electrical connections I can find, and that green vacuum pipe that goes to the EMS.

Very recently, on full throttle with the turbo ON (and only then) the car misfires and stutters a bit. It's a sensation like it's missing on one of the cylinders, or someone's switching the turbo on and off quicky. I can't hear if it's dumping or not because at that rpm things are too noisy.
Again, new plugs and HT leads fitted, and connections checked, but no joy. The car runs OK-ish if you don't floor it.

Any help very very much appreciated (or its to the Alfa dealer for a big bill)...

[Alex]

Try to check the lambda-sensor, it did solve the same problem on my dedra integrale.
Its a thin cable with a yellow connector in the area of the right head-lamp. it is protected by a rubber coating.
I hope that i works on your car, good luck!

[Eric]

Hi,

Your recent problem with the misfires sounds just like the problem I have with my Delta HF Turbo 16V (1994). At the garage they have been checking nearly everything that can be checked, including the lambda sensor, spark plug leads, map-sensor, TDC-sensor, computer, etc. etc.. Finally they concluded the injectors are not functioning properly at full fuel pressure.

Next thursday they will get them out and clean them. I hope this will solve my problem, I will let you know!
By the way, in my car the "fuel injector light" on the dash does not give any alarm.

Greetings and good luck,
Eric

[Eric]

Unfortunately, the problem with my car was not caused by bad injectors (we found out after having them cleaned).
I will let you know if I know the real cause!

[Leon Fletcher]

Hi all,

I solved the problem with the engine management - took the car in to the Alfa dealers in Carlisle (expensive, but...). They found one of the sensors faulty (knock?) round the back of the engine. The engine management light doesn't come on any more.

As for the misfiring, they have fitted a new fuel filter (last changed - NEVER!) and I've got new (original equipment) HT's and everything's peachy.

Thanks for your help,


Leon

[Miguel Monteiro]

I've a series 3 Lancia Thema turbo 16 v lx, with full poltrona frau interior. I love the car and won't change it for anything.
A year ago the injectors light, on the dashboard, went on at about 5000 rpm, by then the car only reached 200 kph at full throttle.
It took a year to almost solve the problem. I spent a lot of money, I did change everything in that engine, all of the sensors ( not the knock sensor), water pump, thermostat, etc... No results.

Till one day, I incidentally open the fuel cap while the engine was still running and it immediately began to work as it was on 3 cylinders.
I noticed that it pushed lots of air inside, as if I drink water from a plastic bottle, and let no air come inside. I hope you got the picture.

Next day I found three valves near the filling cap, which I replaced. Bingo!!
I had engine again. Now i could reach 220kph with engine working properly, but... The light comes on again by
The time I reach that speed.
My local dealer made a diagnosis connection and a message appeared, over boost problems!!
I changed the pierburg overboost valve, nothing happened Then a new turbo was fitted, nothing again. Fuel pressure valve... again the same result!!!
What can it be? The knock sensor?
Can any one help?

Hope to hear from you soon.

Miguel Monteiro

P.S. the spark plugs are changed every 15.000 kms. as well as the fuel filter.