Delorean driving to its first MOT after lean running / backfiring issue

This is a friends Delorean that I got ready for it’s mot so it can be UK registered.

Engine wouldn’t run, backfiring and running very lean - but if you pressed the airflow plate down it would run.

This turned out to be a kinked fuel return hose at the fuel pump, which caused the system pressure to be over 90 psi instead of around 70psi.

High system pressure makes the air plate harder to deflect, so less fuel and therefore very lean condition.

Other issues:
Cracked spark plugs - causing three cylinders not to fire (and therefore even more oxygen and fuel in the exhaust - throwing the gas analyser out

Lambda control relay incorrect - changeover instead of dual output relay caused the frequency valve to not be powered when the lamda ecu was powered (and vice versa)

Throttle quadrant sticky and loose mechanism causing revs to hang up

Vacuum pipe into manifold not sealing (pipe of pain) - used green locktight to seal it in

Front nearside indicator not working - this was the bulkhead connector under the windscreen washer bottle having a loose pin (and a mouse nest and chewed wires for extra bonus points)

New (1 year old) fuel pipes and filter inside tank had deteriorated and split

Видео Delorean driving to its first MOT after lean running / backfiring issue канала Eliot Mansfield