94 3.0 Mercruiser back fires out of carb

[marinemike43]

Here is what I did...
Installed new fuel pump and rebuilt the carb (Mercruiser carb)
Had to reinstall the distributor to set timing back up.
IT will start and run fine but idles way high.
Also when I gas it real fast it will backfire out the carb then idle low,then when I gun it again it will backfire out of carb then idle high again.

could this be in timing ,carb or both,never had these issues before.

Thanks Mike

 

[marinemike43]

Re: 94 3.0 Mercruiser back fires out of carb

Also, when I throttle forward the accelerator shoots fuel in as throttle plates open,and when backing off throttle it also shoots gas in the carb,is this normal???

Thanks Mike

 

[Fireman431]

Re: 94 3.0 Mercruiser back fires out of carb

Since you also removedand reinstalled the distributor, your timing could be off. That will also cause a higher idle as well as backfiring. Put the engine on TDC of th #1 cylinder and make sure everything is lined up properly. Also, set the timing with a light.