RX8Club.com - Hi, New to the forum, advice sought.

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Hi, New to the forum, advice sought.

Hi, all, great site, learned a lot of information whilst browsing. I have a 2009 (58 plate) RX8 192 which I bought as a non runner, had 58,000 miles and when I pulled the motor it had broken an apex seal on the rear rotor so the rear rotor, housing and irons were scrap.

I sourced a second hand engine with 47,000 miles on and fitted my ancillaries and put the engine in, after putting bit of ATF fluid in the spark plug holes and deflooding it fired up straight away, I got a P2109 DTC which meant the engine wouldn't rev with the throttle pedal and the revs eventually started pulsing between 1000 and 1750 RPM, I managed to clear the fault and drive the car and it revved fine so I left it idling and it had no DTC's and was idling fine.

It eventually stopped on its own and when I restart it the P2109 DTC is there again and now won't clear, it will rev slowly up to 3000RPM then if you don't press anything will hunt again between 1000 and 1750 RPM, I read the long thread about a guy with a similar code who replaced everything and it turned out to be the PCM, has anybody had this problem but with a simpler solution?

I've reset the PCM but it doesn't clear the DTC

Thanks

Quote:

DTC P2109
TP sensor minimum stop range/performance problem
DETECTION CONDITION
The PCM monitors the minimum TP when the closed TP learning is completed. If the TP is less than 11.5 % or more than 24.3 %, the PCM determines that there is a TP sensor minimum stop range/performance problem.
Diagnostic support note
This is a continuous monitor (CCM).
The MIL illuminates if the PCM detects the above malfunction condition in the first drive cycle.
FREEZE FRAME DATA is available.
The DTC is stored in the PCM memory.
POSSIBLE CAUSE
Drive-by-wire control system malfunction
Throttle actuator malfunction
Throttle valve malfunction
PCM malfunction

A busted apex deal on a 2009 is uncommon. I'm also unaware of any 'low power' 2009-2011 RX-8s, they should all be 6-port 'hi power'.

Are you sure you replaced it with a compatible engine?

Hi, thanks for the reply, mine isn't the last 2009-11 model, it's the last of the last series, I managed to clear the fault code and it worked great, took it for a drive and it only lasted a mile or so before it cut out and wouldn't restart, I checked compression but only using a standard piston checker and was getting consistent pulses on front and back rotors between 85 and 100 psi, searching online some say this is fine, some say bad, I realise it's not ideal using these testers but was after an indication.

I'm getting good spark from each plug and got it going again but it sounded like it had a misfire which it showed no sign of before, I'll work through the misfire thread and see what comes up.