so i know its not the sensor i just replaced that so its brand new. While driving my car it started to lose power, buck, and backfire alittle till i shifted down then it went away. When i got home i got the code P0340. witch is the ECU lose the cam angle sensor signal. Any clues? maybe a broken wire that randomly comes lose? Any have a wring diagram of where the wires run in the car.

trace the wire from the sensor to the ecu. test voltages and continuity from it and the ECU. narrow down the break or knick in the line. repair.

well i norrowed it down to this. It only back fires and bucks in the lower rpms.

check the section of the harness that runs by the EGR pipe. It's known for melting wires and causing general havoc

no EGR took it out around a year ago. it seems to happen at the same time in the lower rpms. Its fine through first then i hit 2nd and give it gas and it shutters, bucks, and backfires. i leave off the gas and slowly get back on it and it goes fine, then i hit 3rd and the same thing. so i dont think its a random broken wire. Also have codes for evap and EGR but i have them both removed.

k so i got home today and regapped my plugs to 60 (the coil i have recommends 65). It seems to idle alot better, but its still doing it. Seemed to help the stuttering problem but it still happens. Im thinkin my plugs are shot. im gonna go get new ones tonight and see if that helps at all. Forgot to add after driving it this afternoon i pulled the codes again and the CAS code is gone. I also tring my hardest to "knock loose" that broken wire. Yea theres no bad wire.

i had the same problem i changed my iac and my tps and it went away........

chnaged my plugs and no change. Found out ti does it in all gears whenever i put the car under heavy load.

Have you checked your compression and fuel pressure?

no not yet. im gonna try switchin Coilpacks and wires. Would bad gas cause this? The cars been sitting for 5 months with an open fuel line. it kinda reminds me of when you suck up water in your intake.

Originally posted by rshissler
no not yet. im gonna try switchin Coilpacks and wires. Would bad gas cause this? The cars been sitting for 5 months with an open fuel line. it kinda reminds me of when you suck up water in your intake.

Fuel that's going bad can cause issues like this. I'd drain the tank, replace the fuel filter and run something through the system to degunk it. I've got a little coctail that I've used over the years with great results. The recipe is available in This thread

Originally posted by rshissler
no not yet. im gonna try switchin Coilpacks and wires. Would bad gas cause this? The cars been sitting for 5 months with an open fuel line. it kinda reminds me of when you suck up water in your intake.

My buddys MR2 did this because of bad ground wires. Maybe try to add a new ground wire off the battery to the body. Just throwing it out there.

Originally posted by rshissler
no not yet. im gonna try switchin Coilpacks and wires. Would bad gas cause this? The cars been sitting for 5 months with an open fuel line. it kinda reminds me of when you suck up water in your intake.

I ran gas almost a year old in my first build. Stupid I know, but it didn't do anything of this nature. Now I did have the same problem under heavy boost and I traced it back to the alternator.

Gas would not address a cam angle sensor cel.

Originally posted by rshissler
k so i got home today and regapped my plugs to 60 (the coil i have recommends 65). It seems to idle alot better, but its still doing it. Seemed to help the stuttering problem but it still happens. Im thinkin my plugs are shot. im gonna go get new ones tonight and see if that helps at all. Forgot to add after driving it this afternoon i pulled the codes again and the CAS code is gone. I also tring my hardest to "knock loose" that broken wire. Yea theres no bad wire.

Gap them to .050".

Yeah, i understand the Coil manufacturer tells you to gap them at .060 but i would never recommend that. Gap to .050 like posted above.

Next would be to check the Cam angle sensor plug. There have been issues under load where the harness flex causes weak spots in the wire to affect the signal transfer to the ECU.

spark plug wires. done.

well i took it out today again it only sputtered twice for me and not as bad. Tomorrow im gonna try driving the car to work and see how she does. might have been bad gas. Now i need to deal with the leaking oil and tranny fluid im having.