MY throttle body is on the way out. Any suggestions for repairs replacement for 1999 Aus compliant 3.0l automatic?
Source for Throttle body
- Thread starter FrogNBoggle
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- throttle body
I've never seen a NSX TB going bad, What's the issue you're having?
We have replacement TPS sensors, might even have a DBW Throttle body laying around but I'd need to search in the warehouse.
We have replacement TPS sensors, might even have a DBW Throttle body laying around but I'd need to search in the warehouse.
Many thanks for your reply; On start-up, the engine revs up and down a few times, from 500~1500rpm, then the Orange TCS and Engine lights come on. Sometimes when driving (with those lights still on), the engine seems to run rough. If I stop the car, turn off ignition, then re-start, the lights stay off and everything seems to run ok. Any suggestions? Thanks and best regards, Paul
Have you checked for any fault codes? would be surprised if its the TB.
The fault is a bit intermittent at the moment, but when it happens, I'll try to get to my mechanic so he can re-check the fault code.
Might be worth doing the inlet cleaning procedure. Larry B has a good one somewhere here on Prime, I have a hard copy if you need it.
I use Subaru cleaner, small can and works well. Worth a shot if it hasnt been done for a while.
Cheers Scott
I use Subaru cleaner, small can and works well. Worth a shot if it hasnt been done for a while.
Cheers Scott
My car is doing something similar, any chance of receiving an electronic copy of the article?
What i would test,
- Pull radio fuse in front left fuse-box
- Test drive the car until the symptom pops up.
- Pull the codes (procedure listed in DIY section) (I recall Australian delivered cars have UK spec wiring with JDM style ECU and OBD-II)
- Post up the codes here, this will let us know what the ECU is thinking.
Anyway then you can use carburetor cleaner to clean out the intake, check the PCV attachment too.
What you describe sounds in a 90-94 car as a IACV and Thermo valve issue (air in coolant related)
The DBW system does away with the large part of vacuum/thermal side of idle regulation.
I would check if the DBW is seeing it's TPS sensor, and that the intake manifold sensors are connected and work properly (IAT, MAP)
Also check if all vacuum, and pcv lines are connected properly.
Recap after cleaning the throttle body,
- PCV
- Vacuüm connections
- check if the map sensor (if in doubt of reading) check the fitting and socket
Also take a look at the top of you throttle body (near the - negative jump terminal) check if there is marking line on the idle screw (pointing to the cabin), does it look normal?
- Pull radio fuse in front left fuse-box
- Test drive the car until the symptom pops up.
- Pull the codes (procedure listed in DIY section) (I recall Australian delivered cars have UK spec wiring with JDM style ECU and OBD-II)
- Post up the codes here, this will let us know what the ECU is thinking.
Anyway then you can use carburetor cleaner to clean out the intake, check the PCV attachment too.
What you describe sounds in a 90-94 car as a IACV and Thermo valve issue (air in coolant related)
The DBW system does away with the large part of vacuum/thermal side of idle regulation.
I would check if the DBW is seeing it's TPS sensor, and that the intake manifold sensors are connected and work properly (IAT, MAP)
Also check if all vacuum, and pcv lines are connected properly.
Recap after cleaning the throttle body,
- PCV
- Vacuüm connections
- check if the map sensor (if in doubt of reading) check the fitting and socket
Also take a look at the top of you throttle body (near the - negative jump terminal) check if there is marking line on the idle screw (pointing to the cabin), does it look normal?
http://www.nsxcb.co.uk/showthread.php?6286-NSX-Health-Check-Service/page10&p=63322#post63322
Good article from Kaz here, I will find the hard copy of Larry B and send to anyone interested via PM
Good article from Kaz here, I will find the hard copy of Larry B and send to anyone interested via PM
PM sent
Ok, the throttle body has been cleaned
(Before & after photos)The D.T.C. message; 40-03 Devated TH Position is displayed
Hello Adnan; Is this enough information? The condition has worsened. The Orange TCS and Engine lights come on at every cold start. After running for 1-2 minutes; switch off, then on; the lights go out. Sometimes the on/off process doesn't clear the condition.
Last edited:
OK,
What i would do,
Disconnect the TCS computer, (behind pass seat in a RHD)
Check if the issue returns with full TCS bypass (so no computer no communication)
if it does,
Check in the OBD-II for TPS out put voltage, 0.5 idle and 5v WOT, you can also manual read that on the middle terminal of the 3p connector (splicing required & multi-meter)
Whilst in graph mode of the OBD Reader check if the voltage graph smoothly goes van 0.5 to 5v if you depress the accelerator pedal from 0 to 100%.
If there are dead/flat spots in the graph this indicates a issue with the TPS sensor or if the voltages are to low, to high or not 0.5v idle.
You'd need to remove the tps, replace it check the internal rotor on the throttle shaft and manual calibrate the throttle body (tricky on DBW)
There is a procedure i use for mechanical throttle bodies but that wouldn't apply to a DBW car.
- - - Updated - - -
BTW, also check and clean the throttle body ground cable on the cabin side of the assembly, (i recall the 6mm bolt above the tps, and the 6mm bolt underneath the pvc hose fitting of the manifold)
What i would do,
Disconnect the TCS computer, (behind pass seat in a RHD)
Check if the issue returns with full TCS bypass (so no computer no communication)
if it does,
Check in the OBD-II for TPS out put voltage, 0.5 idle and 5v WOT, you can also manual read that on the middle terminal of the 3p connector (splicing required & multi-meter)
Whilst in graph mode of the OBD Reader check if the voltage graph smoothly goes van 0.5 to 5v if you depress the accelerator pedal from 0 to 100%.
If there are dead/flat spots in the graph this indicates a issue with the TPS sensor or if the voltages are to low, to high or not 0.5v idle.
You'd need to remove the tps, replace it check the internal rotor on the throttle shaft and manual calibrate the throttle body (tricky on DBW)
There is a procedure i use for mechanical throttle bodies but that wouldn't apply to a DBW car.
- - - Updated - - -
BTW, also check and clean the throttle body ground cable on the cabin side of the assembly, (i recall the 6mm bolt above the tps, and the 6mm bolt underneath the pvc hose fitting of the manifold)
