My Honda has a strange problem that is vexing my mechanic. While I am driving, the engine spits and sputters and sometimes dies. I try to restart and it starts right up but runs rough. Sometimes it takes a while to start back up. If I wait a few minutes, it will start again and drive fine for a while. Then it will do it again. After it is warm or when it is cold at the start, it won’t do it.
My mechanic cannot get it to do it long enough to diagnose. The computer is not throwing any codes.
I believe it is electrical because when it does this, the speedometer goes crazy bouncing up and down. Electical problem also may explain why the computer is not throwing any codes.
I need to narrow it down because my mechanic is reluctant to start trying things as I don’t have a lot of money to throw at this.
Any help would be greatly appreciated.
Thank you.
KDH
Are the battery cables clean and tight? Are all the grounds clean and tight?
On some engines – not sure if it applies to yours – the ECM uses the speedo information to set mixture parameters for the fuel injection. Since the speedo is going wacky, and presuming you’ve already made sure the battery and connections are ok, I suspect a faulty speed sensor is confusing the car’s computer. Usually the speedo sensor is a replaceable part which screws into the transmission and has an electrical connector on it .
There was a known issue on earlier Passports where the vehicle speed sensor driven gear would get chewed up and give faulty readings as George described above.
Have a mechanic pull the vehicle speed sensor and check the driven gear on the end of it.
I’m also curious about the age of the battery and battery cable condition. A poor connection combined with heat can affect voltage and electronics can get a bit stupid.