Strong hesitation when cold
- Thread starter CL65 Captain
- Start date
Still outstanding.
Just replaced this on another make car with the same symptoms - crankshaft position sensor?
The mystery for me, is why this only happens for the first 2-3 minutes and then it runs like a champ. Idles fine when cold, seems to drive fine when cold but then it hesitates like the cats are clogged or it's pulling timing. You start driving steady state 2-3k rpm and all of sudden rpms start dropping and no power like it's bogging down and then a second later back to normal. After a few minutes the car drives completely normal. And when I say "cold" it doesn't matter if OAT is 30F or 80F, it's when the car has been sitting for more than 30 min. Even when I get in after an hour and temp gauge/water temp is warm but the engine isn't necessarily (cools faster than the water) it will hesitate for the first couple of minutes when driving.
Is there a way to test the crankshaft position sensor or is it another one of those parts I just have to throw money at and see if it fixes it (I have now replaced fuel pump resistor, fuel pump, 6 coils, ignitor, valve adj, 2x 02 sensors, WT sensor, battery and ground wire all of which did nothing)?
I drove it 180 miles each way to Putnam Park last weekend, and drove all weekend on the track with not a hiccup but had to let it idle and warm up first. Ran like a champ unlike this Z06...
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I feel your pain. I replaced the coolant temp sensors like redbird posted (excellent article BTW), then the TPS, and then the CPS. This was on a Jeep.
Look at page 11-46 of the Service Manual for the CPS troubleshooting. Do the basic ohmeter test before the engine is started and the sensor warms up, and then make sure all the connections are good if it passes when putting back together.
Good luck.
Look at page 11-46 of the Service Manual for the CPS troubleshooting. Do the basic ohmeter test before the engine is started and the sensor warms up, and then make sure all the connections are good if it passes when putting back together.
Good luck.
Cl captin, PM , I want to send you a known good MAP sensor to try, also want to discuss egr possibilty
Ben
Ben
I have been working with Ben from Daisy Auto over the phone and disconnected the EGR, made sure the vacuum line was clean and also removed the MAT sensor and cleaned it. There was some crud on it but it was in good shape. Sprayed contact cleaner on the connection clip for the MAT and the clip for the EGR and reconnected everything. Took it for a spin and so far no hesitation. It's hard really to tell as I only have 2-3 minutes of driving before the temp starts to come up and then you have to let it sit for 1-2 hrs before trying again. But so far, so good - no hesitation. Will get to test it further when I get back in town next week.
I want to say thanks to Ben @ Daisy Auto, and if anyone is in the Mid Atlantic area I wouldn't hesitate for a minute to take your NSX to Ben. He has been very patient and very gracious with all his help.
Jim
Dirty MAT sensor.
I want to say thanks to Ben @ Daisy Auto, and if anyone is in the Mid Atlantic area I wouldn't hesitate for a minute to take your NSX to Ben. He has been very patient and very gracious with all his help.
Jim
Dirty MAT sensor.
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A vacationing penguin is driving his through Arizona when he notices that the oil pressure light is on. He gets out to look and sees oil dripping out of the motor. He drives to the nearest town and stops at the first gas station.
After dropping the car off, the penguin goes for a walk around town. He sees an ice-cream shop and, being a penguin in Arizona, decides that something cold would really hit the spot. He gets a big dish of ice cream and sits down to eat. Having no hands he makes a real mess trying to eat with his flippers. After finishing his ice cream, he goes back to the gas station and asks the mechanic if he’s found the problem. The mechanic looks up and says “It looks like you blew a seal.”
“No no,” the penguin replies, “it’s just ice cream.”
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I have been working with Ben from Daisy Auto over the phone and disconnected the EGR, made sure the vacuum line was clean and also removed the MAT sensor and cleaned it. There was some crud on it but it was in good shape. Sprayed contact cleaner on the connection clip for the MAT and the clip for the EGR and reconnected everything. Took it for a spin and so far no hesitation. It's hard really to tell as I only have 2-3 minutes of driving before the temp starts to come up and then you have to let it sit for 1-2 hrs before trying again. But so far, so good - no hesitation. Will get to test it further when I get back in town next week.
I want to say thanks to Ben @ Daisy Auto, and if anyone is in the Mid Atlantic area I wouldn't hesitate for a minute to take your NSX to Ben. He has been very patient and very gracious with all his help.
Jim
Dirty MAT sensor.
Is this called a MAP or MAT sensor and what does it do and where is it located???
MAT. Manifold Air Temperature. It is on the top front of the intake. Remove the front fuel rail cover and it's sitting right there. The MAP is in the control box on the rear drivers side near the shock top area.
But it didn't solve my problem. Neither did unplugging the EGR valve. Back to square one.
But it didn't solve my problem. Neither did unplugging the EGR valve. Back to square one.
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So it looks like this only occurs during open loop and not during closed loop operation. During open loop most sensors will not be used and it is running from a predetermined map. If you haven't done so already, might be worth pulling the clock fuse to wipe the memory and go through the idle calibration procedure. I think it can take up to 200 miles afterwards to remap.
Having said that, the CPS is used during open loop. Might be worth checking that as well as anything else that is used during open loop.
Having said that, the CPS is used during open loop. Might be worth checking that as well as anything else that is used during open loop.
http://itisfresh.com/how-to-reset-ecu-acura-nsx.html
Hello Captain, check out this link to reset the ECU, I hope you find the gremlins that prevents you from sleeping well :frown:, I wish you luck and good courage for the future :smile: ... KILLING the GREMLINS
Hello Captain, check out this link to reset the ECU, I hope you find the gremlins that prevents you from sleeping well :frown:, I wish you luck and good courage for the future :smile: ... KILLING the GREMLINS
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Ecu has been reset many times, this problem has been ongoing for months and many miles.
Sent from my PC36100 using Tapatalk 2
Sent from my PC36100 using Tapatalk 2
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Problem fixed yet?
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