1995 Mercury 200hp EFI intermittent issue

[johnhammersmith]

Motor has always had a small delay when you smash the gas to get on plane but this weekend a few times when I smash the gas it idles up and plows but won't open up and get on plane. It has new plugs and fuel filter. Checked behind prop for,possible line or string bound up behind. Checked lower unit grease and no water and is full. Checked bushing in prop and it is good. Motor will rev up perfect in neutral. Any help would be greatly appreciated.

 

[Faztbullet]

Need to check spark on cylinders and TPS readings

 

[johnhammersmith]

Thanks will check those tomorrow.

 

[johnhammersmith]

Spark is good on all cylinders. Checked TPS and its showing 4.24V at idle and goes to 0.16V at full throttle. Seems that is backwards from what I have been reading.

 

[johnhammersmith]

Unplugged TPS and tested ohms and it is working correctly. Ran the boat for 10 minutes at almost full throttle. Floated for 15 mins and ran it again and is working flawlessly. Have I mentioned how much i hate intermittent problems.