Hi there --

The engine -- a Euro M110.984 -- has just had a rebuilt head.

It's got a rebuilt fuel pressure regulator, fuel distributor and warm up regulator.

The timing is correct. Fuel pump seems okay. There's a new cold start valve and the auxiliary air valve seems okay, too.

It's a 78 so no oxygen sensor.

Regardless of how the CO mixture is adjusted -- toward rich or lean + I wish I hadnt touched it -- Im getting these issues:

Starts well cold.

Some backfires when the engine is revved.

Begins to die when warm

Then hard to restart.

Does anyone have any advice? Or maybe know of anyone who can do a metering/ fuel pressure diagnosis in the Brooklyn area?