Extremely lean idle, stumbling, and hesitation problem
11-07-10, 03:23 PM
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Extremely lean idle, stumbling, and hesitation problem
Recently my FD decided to start acting up on me. It's street ported with a gt35r using the PFC.
It happened for the 1st time about 4 months ago. I drove it completely across town running great and then it fell on it's face. It leaned out really bad, felt like a tractor, had no power, and hesitated to raise RPMs. This happened after the engine bay had been power washed so I figured that maybe water had possibly gotten into a connector or something of that sort. The car sat for 2 days and when I started it 2 days later it ran just fine all the way across town back home.
Second time it happened, about 2 weeks after the first incident , it did the same thing. Ran perfectly fine all the way across town then fell on it's face
Now it acts this way as soon as it is warmed up. It runs smooth and with a decent AFR while warming up. It has somewhat of a high idle but nothing crazy, about 1400-1600 RPM. Once it warms up the idle drops to ~900 RPM where it should be however the AFR drops to about 17 to 18!!! The map sensor is fine and the fuel pressure is at about 38psi at idle. It was tuned at 40psi so I'll be getting it back up to that however it doesn't seem to be a large enough drop in fuel pressure to cause these issues at idle.
I can only think that it's some kind of sensor issue however it's nothing obvious on the PFC, or something strange with my external fuel pump wiring. I have my in tank pump feeding a surge tank and then my external fuel pump (a1000). It's never given me problems before however I had a weak battery the first two times this happened and when it would happen it would kill my battery so it almost seems as though the fuel pump isn't getting enough power (volts, amps, whichever it is... I'm not one for electrical matters).
Here is a short clip of how its acting (sorry for the buzzing at the beginning it's my phone vibrating). I also attached a log from the pfc. I could only attach a 100KB .txt file so I just included a few seconds of the log which correspond to the video clip (when I turn the car off that's the end of the log).
http://www.youtube.com/watch?v=Tq1K7grJuiw
Thanks Everyone
-Candice
It happened for the 1st time about 4 months ago. I drove it completely across town running great and then it fell on it's face. It leaned out really bad, felt like a tractor, had no power, and hesitated to raise RPMs. This happened after the engine bay had been power washed so I figured that maybe water had possibly gotten into a connector or something of that sort. The car sat for 2 days and when I started it 2 days later it ran just fine all the way across town back home.
Second time it happened, about 2 weeks after the first incident , it did the same thing. Ran perfectly fine all the way across town then fell on it's face
Now it acts this way as soon as it is warmed up. It runs smooth and with a decent AFR while warming up. It has somewhat of a high idle but nothing crazy, about 1400-1600 RPM. Once it warms up the idle drops to ~900 RPM where it should be however the AFR drops to about 17 to 18!!! The map sensor is fine and the fuel pressure is at about 38psi at idle. It was tuned at 40psi so I'll be getting it back up to that however it doesn't seem to be a large enough drop in fuel pressure to cause these issues at idle.
I can only think that it's some kind of sensor issue however it's nothing obvious on the PFC, or something strange with my external fuel pump wiring. I have my in tank pump feeding a surge tank and then my external fuel pump (a1000). It's never given me problems before however I had a weak battery the first two times this happened and when it would happen it would kill my battery so it almost seems as though the fuel pump isn't getting enough power (volts, amps, whichever it is... I'm not one for electrical matters).
Here is a short clip of how its acting (sorry for the buzzing at the beginning it's my phone vibrating). I also attached a log from the pfc. I could only attach a 100KB .txt file so I just included a few seconds of the log which correspond to the video clip (when I turn the car off that's the end of the log).
http://www.youtube.com/watch?v=Tq1K7grJuiw
Thanks Everyone
-Candice
11-13-10, 01:17 PM
#3
Funny, mine is doing the same. Runs fine when cold. As soon as it starts to warm up it goes SUPER lean & will barely stay running.
Seems like a sensor issue with open & closed loop.
My car is not tuned yet. But the base map should not act like this.
Seems like a sensor issue with open & closed loop.
My car is not tuned yet. But the base map should not act like this.
11-13-10, 05:03 PM
#4
take a look at your O2 sensor. Sounded like once vehicle into close-loop warmed up, the PFC takes over and controls the AFR and resulting this issue. What happen if you richen the A/F mixture by injecting some butane through the intake?? Can you monitor O2 reading to see if it switches with the butane injected.
-AzEKnightz
-AzEKnightz
11-14-10, 06:06 PM
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Pulled my spark plugs. They were all filthy. The front leading plug was cracked and the front trailing plug had unburnt fuel on it. I'm not sure if this the cause of the problem, or caused by another problem.
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11-15-10, 09:23 PM
#8
Candice, this happened on my blue Turbo II not long before i grenaded the first motor. I would check O2 sensor, knock sensor (if you are using one) and the crank angle sensor. My car had both a failed CAS and a failed O2 sensor. The CAS is very sensitive to temperature. Are you using the stock NGK plugs or the racing NGK's? Also, when is the last time you checked/replaced the plug wires? I have a factory FSM, as well as a PFC manual if you need either one of them. Hope you get it figured out soon! If you need any help with it call me at work at Pj's Triumph Ducati at 323-6700
-Sean
-Sean
11-16-10, 12:09 AM
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Candice, this happened on my blue Turbo II not long before i grenaded the first motor. I would check O2 sensor, knock sensor (if you are using one) and the crank angle sensor. My car had both a failed CAS and a failed O2 sensor. The CAS is very sensitive to temperature. Are you using the stock NGK plugs or the racing NGK's? Also, when is the last time you checked/replaced the plug wires? I have a factory FSM, as well as a PFC manual if you need either one of them. Hope you get it figured out soon! If you need any help with it call me at work at Pj's Triumph Ducati at 323-6700
-Sean
-Sean
Thanks for the advice. I had the heat range 11 Greddy (NGK, same plug) plugs in there and they were very dirty, one plug had a small crack in it. I ordered new plugs however I am not nearly patient enough to wait for them in the mail so I put some NGK 9's in there and drove her around. The problem seems to be solved so far
11-16-10, 12:41 PM
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As soon as I started watching the video I immediately thought "ignition problem". That's the sound of the car running on one rotor basically. Every now and again you hear a few pops of the other rotor trying to fire.
Bad/fouled plugs will do this all day long.
Don't mess with anything else until you get the new plugs in.
Dale
Bad/fouled plugs will do this all day long.
Don't mess with anything else until you get the new plugs in.
Dale
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