Mercury OptiMax

I have a 2000 OptiMax 150. Firtst start of the day fires up great, after a few moments of idle in neutral will generally die. Attempts to start immediately after will not start short blast of start & then dies. Must let sit a few minuets then start after turning key on & pumping 3 times. After start must quickly shift into gear to keep running. Both in neutral or in gear as long as it is above idle the engine runs perfectly. Previously the engine would occasionally miss & hesitate, i changed injectors(tech said the resistance readings were to low) changed plugs(platnium),plug wires, wire harness, new batteries,heat sensor. Engine runs great above idle. Problem will not idle & hard starting. Prior to all this it ran great & reliable, everything started after alternator mounts wore out and alternator started vibrating. REbuilt alternator. No codes on computer per tech w/DDT. No codes for faulty computer but that's all we can think of to do. No way to test computer or put on someone else's motor to check. Can anyone give me some insight on a new direction short of buying a new computer & having the same problem. Any help will be appreciated
aloha

earl

Re: Mercury OptiMax

The first thing with Opits is check air & fuel pressures.
air-80 pis
fuel- 90 psi
And make sure you get a gauge with a dump valve,so you can check for fuel in the air side.if you find fuel in the air side most likely you have failed fuel or tracker valve. But just this last summer at work, I had a failed ECM that was dumping fuel into the air side. this was on a 135 Opti. I was was lucky that day, the dealer rep stopped by, and reloaded a ECM for me, that was after I went out to 225 Opti in the yard and swaped out the ECM, sure it ran rough, but it did verifi the ECM was at fault.

Re: Mercury OptiMax

thanks, will get my tech to try & report back to you