2002 4.3 mpi hard starting

[rickm]

I have a 2002 with twin 4.3 mpi engines and 1 engine is hard to start cranks and cranks and then maybe it's start. I turn the key on I hear the fuel pump
and wait about 5 -6 seconds and try. Sometimes it start right away this engine only has about 10hrs. on it. When running I think it's running to lean I can smell it. Any thoughts ???

[mmwjr]

Welcome aboard

New engine should be covered by installers warranty. Being MPI the ECM can be read for fault codes.

Is it a completly new engine and all systems or a new/rebuilt long block?

[Phillbo]

Like Mike said, have the codes scanned. Also have the IAC checked out.

[rickm]

I did the install and it's was a long block

[rickm]

Replaced the IAC on both engines

[mmwjr]

Originally Posted by rickm

I did the install and it's was a long block

Ok so it has the original fuel system. The cool fuel pumps are know to have blockages in the lines from being internally painted. You may want to swap them between engines to see if it makes a difference. Also try measuring the fuel pressure at the rail to ensure it's in spec.\

Have you verified spark when it's not starting?

[rickm]

yes, it has spark because that was the first thing I checked from coil to dist. and fuel pressure. Thinking back when I installed the new engine and fired it up first time. It took
a long time to fired it up when new. So I'm thinking maybe ECM or Knock sensor but before I throw parts at it I'm going to have a guy check it with a code reader.

[mmwjr]

Verify base ignition timing is correctly set.