first of all sorry for my english, I'm Italian. I just finished restoring my s2 but I have a problem. if I stay at fixed rpm, the engine makes holes, is not regular. to a idle and full load is fine. I changed dizzy, sparks, metering unit, fuel injectors, fuel pump, coil. the engine is standard: normal pressure turbo, 12deg timing, idle CO at 1.5%.
I can not find the problem, I'm going crazy

 

nothing?

 

1st post makes no sense.

 

holes???

 

exactly the title makes no sense either, What is actually empty? Fuel, oil, water?

Why dont you type in Italian and use a translator to convert it to English?

 

Think he means when holding a constant rev, the engine jumps ,i would advise the car having a proper set up

 

exactly Twins , what can I do to fix this?

PS: sorry, it is very difficult to translate technical words

 

that would be worse tbh. Translators suck

 

Maybe you should look for a boost or vacuum leak.

 

i checked the vacuum leak, but nothing. at idle and full load is fine.
i also tried to change the temperature coolant sensor and the thermo-switch. the problem goes away if retard a lot the ignition timing.
this information can help?

 

Yes it does. Get it set up.

 

i set up the ignition timing and the fuel mixture with the haynes manual

 

Just get it set up, it'll sort the problem out and the tuner will find anything wrong with the engine and fix it.

Don't mess around with the fueling yourself if you don't understand the Bosch unit.

 

is your pontiometre the sensor on the flap where you give throttle gaz there are 3 postion idle load full load

 

I think we're talking flat spots here fellas

 

Fuel pressure regulator