3.5 flapper lumpy when cold

As thread title.

When I first start the 3.5 efi in a morning it runs really lumpy until warm.

If I switch over to LPG it runs a lot smoother.

Coolant tempreture sensor maybe??

Kieran

I had that problem on my 3.5 RR turned out to be the engine ECU it's a known fault.
Re the coolent sensor the default setting is cold so if you had a similar problem when the engine is hot then yes the sensor is faulty.

No, once warm all is good on both Petrol and LPG.

Any other suggestions??

Two things to try as u never know.
Unplug the cold start injector, it never works in the uk as it never gets cold enough.
Unplug the coolent temp sensor and start the engine from cold, u will need plug it back in as the engine warms up.

Other things to look at are the thermotime switch and the extra air valve.

Is the cold start injector the one attached to the plenum??

If so, mine has the plug disconnected.

Whats the thermotime switch and the extra air valve??

Kieranzxt said:

Is the cold start injector the one attached to the plenum??

If so, mine has the plug disconnected.

Whats the thermotime switch and the extra air valve??

Click to expand...

Thats the one on the side of the plenum.
Thermotime switch is located in front of the coolent temp sensor it looks similar.
Extra air valve is fitted to the o/s of the inlet manifold just above the temp gauge sensor, it has a round-ish front with a hose at the front and one at the rear.

Both items depend on the version of your engine.