Re: 1994 225hp backfiring
Sorry but this engine does not have gaskets ..it uses o-rings and can withstand a lot of overheats before failure.
Check the shift interrupter switch on the shift bracket as this kills cylinder 2.4.6 and will cause a miss and low power. Also recheck the heat sensor by disconnecting wires and retesting ,if it still sounds it possible the TPS has failed as manual states it sound horn 15 seconds after ECU detects failure in either sensor.
OK in an effort to find where the alarm was coming from I went through the following with ignition on and alarm activated:
1. Disconnected both leads from oil tank sensor. No change. Plug wires back in.
2. Disconnected all three leads on overheat sensor. No change. Plug wires back in.
3. Disconnected the connector on the TPI. Alarm silenced and then returned about 15 seconds later. I moved the throttle arm to cause movement in the sensor and the alarm silenced but returned after about 15 seconds and then moving the throttle arm had no effect after that.
If I turned off the key and turned it back on I can recreate this every time. Alarm activates disconnect TPI and alarm goes off and comes back on in 15 seconds. Move the throttle arm on the carbs and alarm silences but returns in 15 seconds and this only works once in the cycle.
So am I to assume that my TPI is bad? I want to be sure as this is an expensive part to throw at it without knowing. Also, can a bad TPI cause the miss firing that I am seeing?
Thanks for the help.