A little story

[Immenson]

Hello everyone. I'm new to nsxprime but I've been lurking on here for years now. My dad actually got an NSX in 2005. Completely stripped and he rebuilt it to its original condition with the exception of downforce nsx-r hood and tail. The thing is he never drove it too much and he always let other people drive it. You can tell the car has taken a beating thanks to those people not caring about my dad's car. You know they've been smashing it every chance they got. Now that I'm 18 dad wants to give me the car but he wants to fix all the problems it's accumulated after years of abuse. Slowly I want to fix this car and bring it back to its prime. I love this car more than anything and I wouldn't trade it for a damn thing. Right now we're trying to get it to start because the transmission blew thanks to someone racing in it. We got the transmission rebuilt but now another problem came up. It started before just fine but now it won't hold idle and is throwing up 5 misfire codes and various knock sensor codes with the TCS light on. So we sent out the ECU after checking all the wires. I'm gonna start posting my progress here with pictures if anyone cares. If anyone can also help maybe with parts or information that would be great! Thanksgiving you!


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[Sportsmind4me]

Ahh, to be 18 again and receive a free NSX. You're living the dream! I for one would be interested to see pics and read about bringing the car back to life. Good luck!

 

[Larry Bastanza]

Make sure you check the ground wires on the engine.....

 

[Immenson]

Update: I checked all the ground wires and I had some O2 sensor codes so I checked all of those too. Maybe there's a pinched wire I didn't see. ECU came back. Apparently fluid leaked everywhere and they upgraded the capacitors. Still won't rev past 4000. Checked the O2 sensors. 1 of them seems to be faulty and will post when it comes in. Got some new rims because the ones on here are bent. So stoked for its completion.

 

[Immenson]

Its been a while since I've posted but since then I've sent back the ecu to get it fixed only to have it back and not fix the problem. I did a compression test and now it seems to be a timing problem so I'm going to change the timing belt. Most of the car is still in pieces and ive taken off everything that needs to be repainted. Also purchased 4 of the 02 stock wheels from nsxtar.

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[goldNSX]

If your story IS true: if that is the (barely recognizable) car in your post of October could you please also represent a list of people who were able to rape this car so bad and give each of them a really good beat-up until their face looks like (or worse) the car in the picture above?

If the compression test is so bad the TB must be far off and the engine is over the Jordan. If you check the timing first and find that it's ok you have a serious problem a TB won't fix.

 

[Jinks]

Zero compression? I hope you have a good job.

 

[Old Guy]

Its not clear to me what kind of belt related valve timing problem would give you 0psi, 0 psi and 175 psi on the same cylinder bank; but, check away! Getting the valve timing so out of whack that you have 0 psi would lead me to think that you would have a valve - piston interference problem and 0 psi on all the cylinders on that bank. I am more inclined to think damaged valves on the two bad cylinders - if the problem is related to the valve train. I would be inclined to avoid turning the engine over at this point because whether the problem is above or below the head level, further rotation may be making things worse.

Removing the valve covers might give you some idea as to what is going on. Head removal to facilitate further diagnosis is possible with the engine remaining in the car; however, once you get that far along its probably wise to make a decision as to whether you do a complete engine removal. Typically I would suggest a leak down test as a next step; but, 0 psi compression is a bit far gone for a formal leak down test with flow measurement. You could do a leak down test on the cheap by pressurizing the failed cylinders to 15 - 20 psi through the spark plug holes (restrain the crankshaft so it doesn't turn) and listen for where the air is exiting. If the test reveals air leaking back into the intake and / or out the exhaust, then the problem might be limited to the head (although bent valves usually mean dinged pistons). Air leaking into the crankcase suggests bad things below the cylinder head and you should plan for complete removal of the engine from the car.

As Jinks obliquely suggests, make sure your money printing machine is well oiled. Nothing on a C series engine comes cheap.

 

[Immenson]

Thanks for the suggestions. Will check everything as soon as I figure out how to get the alternator out. My dad was the one who told me the timing was off and the first thing was to check the belts etc. I have someone helping me now but pray to the nsx god that it isn't that far gone.

 

[Immenson]

Okay. I've had a long month and after changing belts, pulleys etc. The car still has the TCS and 4000 rpm. Is it possible it could be an ecu issue? Trying to figure out any solutions before I have to resolve to fixing the engine.


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[Immenson]

Actually the scanner won't even communicate with the ecu anymore which leads to speculation that it could be...


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[Old Guy]

So - you have resolved the 0 psi compression test problem on the two back cylinders and everything is now good compression wise?

What year is the car? You refer to using a scanner so I presume that it is at least OBDII and drive by wire? Is it a 3.2 l engine?

In post #4 you talked about the ECU being sent out for repair and that 'fluid leaked everywhere and they upgraded some capacitors'. Was the 'fluid' the electrolyte from the capacitors or was the ECU subjected to some other fluid such as being immersed in water? There are electrolytic capacitors in the NSX ECU; but, from what I remember not a lot. Primarily ceramic capacitors so I would be a bit surprised about electrolyte being 'everywhere'. However, if the capacitors did leak, the traces on the circuit board may have been damaged. If the traces were not repaired (which may be impossible if the ECU is a multi layered board) then capacitor replacement / upgrading will not address the problem. Only physical inspection of the ECU board will determine if the board has been damaged.

I seem to recall that the NSX has a complete failure mode option that puts the ECU in to a limp mode if the primary controller fails. In the service manual they have a brief description of the back-up mode; but, no details on the characteristics of that mode of operation. If error codes and communication are managed by the primary controller, then if it died that might kill communications on the OBDII port and leave you with a car that is only running in limp mode. However, I this is way beyond my detailed knowledge of the NSX ECU - you would need to talk to somebody who has actually experienced and diagnosed the limp mode of operation.

 

[Immenson]

Oh man. Quite the couple years it has been. I have a number of updates. I printed some money as a couple people suggested. Turns out transmission instead of getting a new ecu and srs ecu I got an aem infinity and did the wiring and what not. At this point in time I'd rather have a running car than a completely stock dead car. We had some issues getting it started and it would crank but never turn over. Took a couple of guys and a lot of time but we diagnosed it to a faulty ignition module. Didn't even know it had one. But car starts. Laying on fresh paint. Planning on finishing exteriir and going for a full interior rebuild by the end of the month before getting it tuned. Wish me luck.

 

[Immenson]

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[Old Guy]

Soooooo, begs the question. 0 psi, 0psi and 175 psi compression test on the rear cylinder bank - what was that about? Somebody forget to screw in the compression tester in the spark plug holes during the test on those cylinders or just kind of jumping over that problem for now?

 

[Immenson]

Yea I did the compression test a couple more times afterwards with a different kit and I never got 0 psi from either cylinders. Can only trust your own tools.


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[Lude_2_NSX]

Yea I did the compression test a couple more times afterwards with a different kit and I never got 0 psi from either cylinders. Can only trust your own tools.


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Glad to see you are moving forward in this project! There are quite a few NSX owners around the bay area to reach out to if you need any local support.

 

[JLCoolman]

Glad to see you're still at it.

Good luck!

 

[furinax]

You should start your own build thread!