Mercury 150 EFI Problems
 

I have a 1996 mercury efi 150, a few months ago it started running bad so I replaced all the fuel filters and plugs. After that it ran fine on short trips, but the other day we took it out and ran from Ellenders to the pogie plants and it just died. I put it in nuetral and it starts right up, run a fews miles back in and it died again. Once it warms up good it dies but will start right back up and run sometimes a few miles or a couple 100 yards. Just wondering if anyone ever came across this. Thanks....

Are you running non ethanol fuel or always use an additive?

I have heard that a crack in the Stator will cause an engine to do what your engine is doing.

Best to just let a mechanic look at it instead of guessing. It can cost you more in the long run changing parts looking for a fix.

Running non ethanol in it.

Stator can cause these issues also.

Stator coils. Magnetic pick ups can be bad. Is it throwing an alarm? There should be a ground pad where the efi is grounded as well as Cdi make sure the grounds aren't loose and have good metal with no corrosion. U said it WAS running bad. Bad how? The fuel pick up hose may not be holding together causing air causing efi to miss and **** off. Checked fuel pump? Find it open end pick up make sure ur getting gas to it then plug it back up then open end sending side and make sure ur getting good fuel out of it. May take 2ppl one to crank it one to check it. Pm me I've went thru so much issues with big motors I am almost a pro... Lol. That ground pAd was my issue. It will send CPU false signals like "efi not enough fuel pressure" shut down. Also when you turn key on not start see if your alarm light flashes. Does it have a throttle pos. sensor? Or fuel pressure sensor on or around efi?