International Lancia Forums

Following a cambelt snap and a replacement of the cylinder head complete with inlet manifold and injectors, I have started to experience some minor, but spoiling faults on my 1991 16v i.e (non Turbo).

The engine starts immediately when started from absolute cold (e.g first thing in the morning) and is an immediate starter when hot (e.g. 5-10 minutes after switching off).
BUT
When starting the engine from warm, or even 8 hours after switching off, it will require several turns before firing.

ALSO
when driving in traffic with the throttle closed and the engine cruising the car will start jerking as the revs pass through 1500 rpm. Application of slight throttle prevents the jerkiness, but slow traffic cruising in gear at low speeds requires constant use of the clutch to avoid progressing in bunny hop jumps.

It feels like a fuel supply problem. I have also noticed a much sharper on/off throttle response since changing the cylinder head and inlet manifold/injectors

I have swapped the following items and nothing has changed in the starting characteristics or jerky cruising at 1500rpm.
- Fuel pressure regulator
- Air bypass valve
- ECU
- HT leads
- Temperature Sensor
- Throttle switch
- Fuel Filter

Any ideas?

Hello Mike,
Could be a sticky injector - changing the injector assembly ain't much fun though. Plugs would be easy to change or check the gap widths and the colour of the plugs would give an idea of weak mixture in one or more cylinders.
What about the air mass sensor is it the original? Perhaps it is not closing fully when throttle is closed.
When warm starting does it help if the throttle is held open when cranking?

Leo

if you think it's a fuel problem, check the fuel lines in your tank. Sooner or later they need replacement. Usually you notice it during higher fueldemand, eg during high acceleration, but if you're desperate it wouldn't hurt to check.

good luck.

ps, i used to have the same problem, but somehow it just went away...