1g CAS in a 2g Talon - Random Misfire

[flashburn02]

Okay, this is unexplainable:
I did the 1g cas conversion to my 2g motor. I ran the car over 500 miles with not a single problem. Just when I think I'm ok, I plug in the logger to check everything out. About 10 seconds after the logger is run I get a CEL. Wouldn't you know it, random misfire. So I did some more research on the forums and found that if you disconnect the TPS it stops the misfire process. However, now I have a CEL always on because I have my TPS disconnected, not to mention on deceleration the injectors stay on because my TPS isn't telling the computer to turn them off. So now I have a CEL, crappy gas mileage, and my car sounds like a SRT4 when I let off the gas. It does still run great though.

I have read over so many threads trying to find a solution. I have been thinking of getting the blacktop CAS, I have the green one. However, I can't find a thread of anyone who actually did the blacktop CAS and it successfully cleared their CEL and misfire problems.

The mileage thing doesn't bother me, nor does the deceleration noise. But if anyone knows how I can make the TPS error light go off, I'd be happier.

Thanks Everyone,
Chris A.

 

[Nicks2319]

Plug back in your TPS, its there for a reason.

And to clarify, why are you running a 1g CAS? Did you 6bolt swap the car? Is the misfire code showing up with no actual signs of misfire? Aka, do you actually feel that there is a problem, or no? Because if the code is coming on, but the car is not sounding like a WRX, then I would just put up with it for now.

I am running a blacktop CAS on mine, and it still gets misfire when cruising above 50. Your options are..

Clear the code every time you start the car.
DSMlink
EPROM chip

Try the blacktop CAS for kicks, it may solve the problem, but it didnt for me.

 

[flashburn02]

Thanks for the reply.

I swapped the CAS because my 2g Crank Position Sensor went bad over winter. The only way to get rid of the misfire is to disconnect the TPS. Since the car has a MAF, the TPS is overkill, except to signal WOT on autos and deceleration on all cars. The MAF controls the fuel delivery while the TPS controls the auxiliary controls I listed allready.

Yeah, you can absolutely feel the misfire, it goes away with the TPS disconnected. Its good to know I should not bother with the blacktop. The question remains though, why would my logger start triggering random misfires? I ran the car hard, very hard for 500 miles with no problems.

PS: Were you at the auto show last night in solon?

 

[Nicks2319]

So why didn't you just buy a new CPS? That would eliminate every single problem...

If you are hellbent on keeping the 1g CAS for whatever reason, then I would say try the blacktop anyway, since many people have had success with it.

And nope, wasn't at the show. Was it a big event?

 

[flashburn02]

I needed to move out of my apartment so I had to swap the 1g cas in for that reason. I didn't have a garage to get to the CPS at the time. I was unable to get the timing cover off and it was about 34 degrees when all this was going on. I'd love to go back to the way its suppose to be, however, my problem now is that I spliced up my wires and lost of the seals to the original plugs for my CPS.

I don't really want to buy a blacktop if it isn't gonna fix everything either. Ugh, the CEL ticks me off too.

And yeah the show was huge, mostly old cars and the imports in the back. The DSM guys stayed late. There was a kid there with a very similar body kit to yours, same color and lambo doors. Under the hood was all stock tho and made me sad

 

[Burnett03]

I dont get random misfire codes and i have a blacktop cas with a 6bolt in my 2g

 

[Dragon TalonTsi]

Yeah, some people get the Misfire codes, some don't. I have link, so I can disable the DTC's, but email me for the write ups and tips on how to keep it from coming back. I have about 6 different tips on it. But I can't post it all here. I am doing my 6 bolt conversion, and that is one of the topics that came up.

 

[flashburn02]

Yeah, some people get the Misfire codes, some don't. I have link, so I can disable the DTC's, but email me for the write ups and tips on how to keep it from coming back. I have about 6 different tips on it. But I can't post it all here. I am doing my 6 bolt conversion, and that is one of the topics that came up.

Thanks for the reply here. I don't know why I didn't think of it myself. I got a different logger, connected it and cleared the code. I put a good 100 miles on it now without it coming back. I really really think the logger I was using generated the problem.

Thanks for the feedback everyone, I hope this thread can help someone solve their random misfire problem. If you have the problem, try clearing the code with the logger, it worked for me.

 

[Bluebyu96Tsi]

This is coming from the magnus website. It helped me fix the misfire code until I got Dsmlink and inverted the signal coming from CAS. Hope this helps you.

IF CHECK ENGINE LIGHTS OCCUR! TRY THIS:
Many people using the 1G CAS on a 2G head have been running into problems with misfire engine codes while at cruise. Many different things have been blamed for this and many different fixes have been attempted.This fix will keep the ECU from looking for misfires at all. This is the criterion that must be met before the
ECU will start to look for misfires:
· 300+ seconds of steady state RPM less than 80% throttle position
· Engine coolant temperature -10C or higher
· Intake air temperature -10C or higher
· Barometric pressure greater than 76 kPa
Now if we can get one of these values outside of the criteria the ECU won’t check for misfires. The value thatwould be the easiest to change would be the barometric pressure sensor. We’re going to add resistance tothis value so that the ECU will see less barometric pressure than what there really is. This will also lean the car out so you should see a performance increase as well. Depending on the car and altitude you might need
to add more fuel with an AFC.