I'm a long time member (all the way back to David's original BBS!) here and have learned so much from the board about niggling problems on the WONDERFUL car I've been the second owner of for 16 years. However, she's recently giving me a few problems with power delivery, a system the car has never had issues with.
Remember here, I've owned this car for over 15 years as a daily driver, with over 20k track miles, so you long-term owners will understand that I feel like I'm 'one' with this car in terms of feeling the most subtle change.
Here's the problmes I'm having, and what I think is the issue. I need your guys feedback:
1)bouncing speedometer - only happens once and a while (odd), but from what I've read here, I 'm going to replace the speed sensor. This started about 3 months ago.
2)rough idle - Revs kinda bounce high (2k) then low (800), but never stalls, however. I replaced the main relay last year when the engine cut out driving on the freeway (Scary here in OC) and wouldn't start. This idle problem became an issue after number 3 became all the time.
3)Very poor power delivery. Used to get similar symptoms when I used a car wash or after the rain, which people thought was due to the covers over the spark plugs being placed on upside down, but I and my mechanic have checked that is not the case. The after-car-wash issue goes away after the car is driven a while; this problem started occasionally, wasn't related to car washes or rain, and has been getting progressively worse. This problem started 6 months ago with just occasionally, when car was warmed up, but progressed to now all the time. Car feels like it is firing only 3 cylinders when I put it under load in HIGHER gears (esp 5th). Lately, I can't pull away from a stop even in 1st hear without the car subtly bucking and jerking like it does hit 6 cylinders then back to 4 then 6 etc. Now, when I apply power it doesn't feel like I get 6 cylinders of power at low revs EVER. If I drop the car to VTEC range revs > 5k I get full power, like she always gives. At low revs, when I give gas, power never dies to zero, but its more like hitting the rev limiter kind of feeling. Like the torque curve dips badly to some new lower plateau. I wonder if this could be the O2 sensor? Back in 97 I replaced one of the O2 sensors when I had an intermittent power delivery issue and it fixed it. What do you guys think?
4) Non-smooth power delivery. This feels like a transaxle issue. Almost like something between the engine and the rear wheels is loose. Feels a bit like the driveline lash we feel at low rev in too high a gear; like the engine is 'shifting' in its position?? My mechanic says replace all 3 engine mounts. Is this a common need in our cars after many miles and years?
Clutch has 125k miles on it (woohoo, beat my first one at 91k!) with NO slip and very little chatter, but I'm going to replace it when the motor drops to fix these isssues. Gonna add CompTech headers as well to the longtime RM Exhaust. Otherwise car is unmodified save CT sways.
Please O NSX gurus contribute you're 2 cents to this beauty's age marks (She's turned 20 years old this October!- production date 10/91).
Remember here, I've owned this car for over 15 years as a daily driver, with over 20k track miles, so you long-term owners will understand that I feel like I'm 'one' with this car in terms of feeling the most subtle change.
Here's the problmes I'm having, and what I think is the issue. I need your guys feedback:
1)bouncing speedometer - only happens once and a while (odd), but from what I've read here, I 'm going to replace the speed sensor. This started about 3 months ago.
2)rough idle - Revs kinda bounce high (2k) then low (800), but never stalls, however. I replaced the main relay last year when the engine cut out driving on the freeway (Scary here in OC) and wouldn't start. This idle problem became an issue after number 3 became all the time.
3)Very poor power delivery. Used to get similar symptoms when I used a car wash or after the rain, which people thought was due to the covers over the spark plugs being placed on upside down, but I and my mechanic have checked that is not the case. The after-car-wash issue goes away after the car is driven a while; this problem started occasionally, wasn't related to car washes or rain, and has been getting progressively worse. This problem started 6 months ago with just occasionally, when car was warmed up, but progressed to now all the time. Car feels like it is firing only 3 cylinders when I put it under load in HIGHER gears (esp 5th). Lately, I can't pull away from a stop even in 1st hear without the car subtly bucking and jerking like it does hit 6 cylinders then back to 4 then 6 etc. Now, when I apply power it doesn't feel like I get 6 cylinders of power at low revs EVER. If I drop the car to VTEC range revs > 5k I get full power, like she always gives. At low revs, when I give gas, power never dies to zero, but its more like hitting the rev limiter kind of feeling. Like the torque curve dips badly to some new lower plateau. I wonder if this could be the O2 sensor? Back in 97 I replaced one of the O2 sensors when I had an intermittent power delivery issue and it fixed it. What do you guys think?
4) Non-smooth power delivery. This feels like a transaxle issue. Almost like something between the engine and the rear wheels is loose. Feels a bit like the driveline lash we feel at low rev in too high a gear; like the engine is 'shifting' in its position?? My mechanic says replace all 3 engine mounts. Is this a common need in our cars after many miles and years?
Clutch has 125k miles on it (woohoo, beat my first one at 91k!) with NO slip and very little chatter, but I'm going to replace it when the motor drops to fix these isssues. Gonna add CompTech headers as well to the longtime RM Exhaust. Otherwise car is unmodified save CT sways.
Please O NSX gurus contribute you're 2 cents to this beauty's age marks (She's turned 20 years old this October!- production date 10/91).
