Jordan Tadelman

Car has been running flawlessly for the past 4 months since I bought it. A few weeks ago I installed a 3.7 SHAWD intake, 70mm skunk2 pro series throttle body, and AEM CAI, car was running perfectly for those 3 weeks. Last night I did a WOT pull in second gear and let out of the gas and felt the engine jerk. I gave it some gas and it was fine, then let out again and it jerked some more. I put the clutch in and the car instantly stalled. I pulled over and tried to start it back up, cranks, but wouldn't start. I went back this morning and managed to get the car to start, but would instantly die. I gave it some gas when I tried to start it and the car would run, but I had to stay on the gas pedal and hold 2000rpm. I eventually got it to "idle" at around 450-500rpm but would stall if given gas. I started to diagnose the issue, no check engine light, no stored codes, no pending codes, full drive cycle was ran. Checked the IACV by pinching the the hose when I got the car to stay running, instantly shut off. TPS sensor is reading 0.48v closed and 4.59v fully open. MAP sensor is a brand new genuine Denso part from Acura. I took all of the timing covers off and timing is correct. Compression is at 140 + or - 5psi on each cylinder. Car is using an unusually high amount of fuel, had it running for about 15 minutes at 500~rpm and went through what seemed like a quarter tank. I replaced the fuel pressure regulator, no difference. Tomorrow I plan to check fuel pressure, check the EGR valve, and install the original throttle body. If anyone has any direction they can offer, it would be greatly appreciated. I have a lot of diagnostic experience but lack the specialty scan tools to get any live data or module testing on this car. Seriously stumped on this one.

Jordan Tadelman

Did some more diagnostic work, turned out to be a failed MAP sensor, reading 0.9v at idle, 1.1v at WOT, and 2.95v at atmospheric pressure, that caused the spark plugs to foul out. New MAP sensor and plugs fixed the problem. My take away from this, if your car suddenly starts stalling and jerking and won't stay running, smells super rich, no CEL, no pending codes, try unplugging the MAP sensor and see if it idles correctly, this will cause the ECU to default to a set A/F ratio at idle instead of interpreting data from the MAP sensor.

zeta

iTrader: (1)

^
Good to hear that you fixed the problem. With that said, I wish I had a tenth of your electrical diagnosis ability, which I suck at. Mechanically, I feel pretty good; however, electrically

In addition, be careful with your WOT pulls in second with the CL-S6. Back in the day there was a tensioner recall for leaking tensioners that caused possible 'valve float' if one got to feisty in the high revs. Third gear is the best gear for 'pulls'; however, you gotta make it from second safely.

relaxed83

The new coil fixed the misfiring. I am still having issues with low rpm. It idles at 750 I think my original 1250 was way off. Sometimes it goes to 500 and I feel like my car shutters a bit. Perhaps it is the O2 sensors or something? I ordered a new MAP sensor for like 15 bucks. I am going to replace all my coils they are already ordered, Denso brand. I returned the Bosch O2 sensors, when I have cash I'll buy the Denso ones. Maybe it's another coil going bad.