stcctln

Hello.i have a big problem with mi dohc sierra.it is underfueling as hell.at idle is a bit rich but as soon as hit the throttle is underfueling to the point of misfire.
So far changed :temp sensor,air intake sensor,map,tps,fuel pump,filter and reg,air filter,and injectors and ecu.
With all of this changed there was absoluty no change.
I've raised the fuel pressure to 3.5 bar.it's a little better but it is even richer at idlle and smells realy like unburned fuel.
As another fix I have mounted a potentiometer inline with the temp sensor and fouled the ecu that the engine is colder.it works but idle is 1200rpm and it realy smells of unburned fuel.

Have you heard of this problem before?
sorry about my english

stcctln

Another question.
checked the air intake sensor today.with the engine at idle and up to temperature
Outside temp 10to 12°C(50°F) sensor reads 2volts.this means 40°C(104°F). And only moves a litle bit when driving.in the morning I will take the reading again when cold.

Is this normal or i have 2 bad sensors(the old one and the new one)?

Gavinbat

Hi,
Is it a Cosworth engine or the DOHC with the black plastic cam cover?
Cheers,
Gavin

stcctln

DOHC N9A non cat.