So my 99 roadking EFI threw an engine light, The engine is running eratic, it will run rich then lean then rich then lean....It pulled up three codes when I scanned it. Crank position sensor, Throttle Position sensor, and Barometric pressure sensor??? Any Ideas

Also The oil for some reason has the worst smell to it you could imagine, almost like something died inside of the lower end....I gave a sample to the Amsoil guy at my buddies shop to have it anylized.

Any input on what these things could be let me know!!

PS: I just bought the bike

 

It sounds like the fuel system dumped a bunch of raw fuel and washed the cylinders, did you have a rough time starting the engine lately?
As for the 3 codes??
Drain and replace the oil, clear the codes, spray some fogging oil in the cylinders, replace the plugs and see what happens.....

 

Do you know if you have an MM or Delphi EFI system? The main differance between the two is MM is an alpha-n and Delphi is a speed-density EFI system. An alpha-n system uses throttle position and rpm for fueling while speed-density uses map pressure and rpm. A barometric pressure sensor implies a alpha-n system. A air pressure sensor on a speed-density system is called a MAP sensor. A MAP sensor is measuring the pressure in the intake while a barometric sensor is measuring the ambient air pressure.

So if you have an MM EFI system problems with your TPS sensor could cause you big problems with your fueling. With the Delphi EFI system it's just used to detect rapid throttle movements for accel enrichment and deccel enleanment. With the MM system the pressure sensor is just used to, basically, detect changes in elevation prior to startup. At high elevations you can be getting 20% less air at a given throttle position so you need 20% less fuel. With the Delphi system though that's how it tells how much air you're getting all the time.

So those two sensors play drastically differant roles depending upon the system you have. The CKP plays the same role in both, that's how the ecm knows when to fire the spark. Generally that's failing to detect the missing teeth that tells it where tdc is. That can range from a severe problem with your timing to a problem only the ecm can detect.

One possibility is that all the sensors are fine and the problem is with wiring or the ecm. The check engine light only lights while a fault is present. During power up it will come on while the self-diagnostics run, go out and come back on for a short while to tell you there's a stored dtc code. I believe it also flashes the blinkers to get your attention. So it seems unlikely you woud miss that you already had two codes stored from intermittant problems. Three sensors failing at once is highly unlikely though.

I would clear the codes and see which come back. If all three come back I would check the wiring. If only one came back then I would replace that sensor first and see if that resolves the problem you're noticing. If it does then I would replace the other two as well. I would assume the codes are legitimate indications of problems with the other two sensors and eventually they will get bad enough to cause a noticable problem.

 

ok, I cleared the codes, started it back up ran for 15-20 seconds and the light came back on. I havent ran the scanner since. Can this indicate anything??

 

Something might be pulling down the 5 volt feed to those sensors?

 

Any idea on how much it would cost to switch over to the Delphi??? I dont think I have heard one good things about the MM fuel injection

 

So I think I figured it out! I pulled a computer from another bike to see if it may be a bad computer. Still run like **** ( runs very very lean, and almost sputters like the timing is off) So next I started following all my wires, Turns out the wire going into the inspection cover was melted, and the cam sensor inside the inspection cover was extremely melted, to the point were all the melted plastic collected in the bottom of the inspection, I pulled the sensor and im going to run to the Stealership today to pik up a new one....51.00$ I think this is going to be my problem. What i think happend is the sensor went, causeing the bike to run wicked lean, causing highheat, melting that sensor...hopefully this is it!

 

Swaped the sensor.....Bike Runs MINT.....nice and smooth minimum vibrations...idles great. almost on the road. couple more little trinkets and ill be good to go

 

Melted wires to sensor shorted out 5 volt power feed to sensors, that is why multiple sensor failure codes were present.