Originally Posted by
costina
Have you tried trimming the co pot on the ecu if L6 or L8? Imo you should be looking at around 11.2 on boost to be safe. Decrease the boost to gain that figure. Also check your fuel pressure and regulator are working correctly. Also as with any cosworth the fuel pump wiring can be a issue not giving enough voltage hence running lean.
Ecu is L8, I didn't tried the co pot. I will leave this for the end as the car was supposed to run well before the rebuild, at least old spars were very black (but it has been off the road for 8 months).
I've checked fuel pump voltage and is not very good. It had 11.5v when running engine battery showed around 13,1v. I will redo the wiring with new fuse and relay.
I will try to install a fuel pressure gauge to check all is correct, is common for those to fail?