CEL pattern...

[Speedmaster]

My first time checking this on this car and I am getting a distinct 3 1 2 pattern. I jumped the blue connector in the photo. I thought all error codes were two-digit codes.

I videoed it in case anyone would like to see it. The TCS light is the one I measured. The engine light blinked fast and I could not discern a pattern.

 

[ftuhy]

Year car?
Were you getting MIL or TCS lights, or are you doing this out of curiosity?

I'm not near my manual at the moment, but a common code you'll get from the TCS (without the TCS normally on) is one for having the hand brake on when moving. Typically that happens when you don't fully release the hand brake lever and notice it a few seconds after the car starts moving

 

[Speedmaster]

ftuhy -

I should say that my ABS light stays on (pump is bad) and the engine light comes on after ten minutes or so of driving. Aside from that, zip. (My TCS light did come on when my VSS was bad. But, I replaced that.)

Car is an NA1/1991.

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<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf" flashvars="file=http%3A%2F%2Fvidmg.photobucket.com%2Falbums%2Fv370%2FMGB-IV%2FMobile%2520Uploads%2F1421534912_zps79900686.mp4&title=">

Here is the test...

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http://vidmg.photobucket.com/albums/v370/MGB-IV/Mobile%20Uploads/1421534912_zps79900686.mp4

Here is the test...

 

[ftuhy]

I'm working off my '96 paper manual and looking at the downloaded '91 - 96 manual, which is available for download somewhere on Prime (Wiki section?). Up front I'll warn that I have NOT dug through the charts to the diagnostic pages for a '91.

It appears you are getting a single "1" code from the CEL light. That is an O2 sensor code. I didn't check the charts for a '91, but for a '96, that would be a low output voltage on the front primary sensor. That possibly applies for a '91. (Manual section 11)

For the TCS you are getting a "3-1" and a "2". The 2 might be easy to clear - that's a 'driving with the handbrake on' code. Remove the CLOCK fuse (7.5A) for at least 3 seconds to clear it. Then, make sure the handbrake is fully pushed down before driving and it should not come back. Even one or 2 clicks up will cause this code.

The "3-1" code is a defective ECM or TCS module, or associated wiring harnesses. (Section 19 in the manual)

Check to see if this comes back after you do the reset via the CLOCK fuse. If so, I'd first try removing and re-inserting the connectors in the ECM and TCS. That can clear off small amounts of oxidation on the connector pins.

I hope this helps.

 

[Speedmaster]

I'm working off my '96 paper manual and looking at the downloaded '91 - 96 manual, which is available for download somewhere on Prime (Wiki section?). Up front I'll warn that I have NOT dug through the charts to the diagnostic pages for a '91.

It appears you are getting a single "1" code from the CEL light. That is an O2 sensor code. I didn't check the charts for a '91, but for a '96, that would be a low output voltage on the front primary sensor. That possibly applies for a '91. (Manual section 11)

For the TCS you are getting a "3-1" and a "2". The 2 might be easy to clear - that's a 'driving with the handbrake on' code. Remove the CLOCK fuse (7.5A) for at least 3 seconds to clear it. Then, make sure the handbrake is fully pushed down before driving and it should not come back. Even one or 2 clicks up will cause this code.

The "3-1" code is a defective ECM or TCS module, or associated wiring harnesses. (Section 19 in the manual)

Check to see if this comes back after you do the reset via the CLOCK fuse. If so, I'd first try removing and re-inserting the connectors in the ECM and TCS. That can clear off small amounts of oxidation on the connector pins.

I hope this helps.

Thanks Frank. I appreciate the feedback. I have my manuals and will double check. Either way, I have a couple of O2 sensors coming from Costa in Greece (used). If the code is correct, I will make the change.

As to the TCS, that could be the actual TCS. I am pretty diligent about putting the handbrake down. Still, I will check and report out.

Thanks again. Am still learning how to embed videos here. It sure helps when you are looking for advice/help.

 

[ftuhy]

On the handbrake, all you need to do is bump it for a few seconds. The code gets stored and you never know it happened unless you happen to pull the codes. I've had that happen a few times.

 

[Speedmaster]

Taking the car to the guru next week. Will let you know what was found.

 

[Jinks]

Have you had headers installed recently? The O2 sensors always fail after they get caked in wd40.

 

[Speedmaster]

Have you had headers installed recently? The O2 sensors always fail after they get caked in wd40.

No, bone stock. Just high miles (335K on the clock). I bought a set of used (what was I thinking?) O2 sensors from a Primer. I will throw those on and see if I still get the error code and the associated engine vibration.

 

[Jinks]

For what's it's worth, I had acura install my dc sports headers and they damaged two of my 02 sensors. I refused they replace them with Oem 300 dollar replacements. I think I bought the replacements from some online parts producer. Since then I have had zero issues. Plus they were only 40$ each with OEM connectors and mounting tabs. My car was also recently on a dyna pack at driving ambition with zero air fuel ratio issues two years later. If you need, I can research my email where I purchased. Just let me know. I am a Oem quality guy myself too. But these are only sensors and zero modifications are needed.

 

[Speedmaster]

For what's it's worth, I had acura install my dc sports headers and they damaged two of my 02 sensors. I refused they replace them with Oem 300 dollar replacements. I think I bought the replacements from some online parts producer. Since then I have had zero issues. Plus they were only 40$ each with OEM connectors and mounting tabs. My car was also recently on a dyna pack at driving ambition with zero air fuel ratio issues two years later. If you need, I can research my email where I purchased. Just let me know. I am a Oem quality guy myself too. But these are only sensors and zero modifications are needed.

Thanks, good info.

BTW, my low rpm vibration is coming on both in-gear under acceleration and at still (i.e. no clutch engagement). I also note that my CEL comes on after 15-20" of driving. So, combined with the error codes thrown by OBDI, I hope it is only an O2 issue. Otherwise, the engine has plenty of horsepower.

 

[Jinks]

That almost sounds like a misfire or a coil pack issue. Never heard of those symptoms.

 

[Speedmaster]

That almost sounds like a misfire or a coil pack issue. Never heard of those symptoms.

Actually,that is what the NSX guru thought as well. He gets the car next week and will throw n the coil packs.

 

[Jinks]

I had chased dragons in my 91 for engine response issues. What a pain in the ass that was. I had zero cel codes to go off of too. Coil packs checked out via an ohm meter. Unfortunately that is the primary side only. You cannot test the secondary side to my knowledge. Low and behold, I changed all three rear bank coil packs since they had slight residue and presto. No problems since. Also found the coil pack gasket missing, Doh! Now, I even cover the rear bank with a bag when washing. Even with the gasket, water always finds its way up in there. Good luck with your findings.

 

[Speedmaster]

I had chased dragons in my 91 for engine response issues. What a pain in the ass that was. I had zero cel codes to go off of too. Coil packs checked out via an ohm meter. Unfortunately that is the primary side only. You cannot test the secondary side to my knowledge. Low and behold, I changed all three rear bank coil packs since they had slight residue and presto. No problems since. Also found the coil pack gasket missing, Doh! Now, I even cover the rear bank with a bag when washing. Even with the gasket, water always finds its way up in there. Good luck with your findings.

Interesting, Jinks. Am curious if this issue goes away with later models. Aren't the coil packs different n say a 1994?

 

[Jinks]

I think the 91-94 years have different front and rears while later models use all 6 of the same. Always best to just order them off year of car.

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Do you have a 94? Lucky you. Shad over at Driving Ambition was telling me of all the nsx' he's worked on over the years, the
94 model always pull the hardest and dyno with the most output. Which I thought was strange. Maybe a really good mechanic built the motors in 94. My car goes in on Saturday for ctsc install. Can't wait!!!!!

 

[Speedmaster]

I think the 91-94 years have different front and rears while later models use all 6 of the same. Always best to just order them off year of car.

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Do you have a 94? Lucky you. Shad over at Driving Ambition was telling me of all the nsx' he's worked on over the years, the
94 model always pull the hardest and dyno with the most output. Which I thought was strange. Maybe a really good mechanic built the motors in 94. My car goes in on Saturday for ctsc install. Can't wait!!!!!

No, mine is a 1991.

Good luck with the CTSC. Report out to us all about the performance gains, drive-ability.

 

[Jinks]

The car dyno'd at 251 peak hp with k&n intake, taitec jgtc exhaust, and dc sport headers. I have recently gone Oem intake with Df snorkel. I noticed to "me" a significant decrease in low end throttle response. Therefore, I think I am going to have Shad dyno the ctsc with Oem intake vs k&n intake just to see as seen in my na performance thread.
Thanks.

 

[Larry Bastanza]

The issue with the coil paks is really not electrical. You can test them all day per the manual and they will be fine. The issue is the fitment as they go over the spark plug, it must seal tightly. If you take the coil pak out, then insert the spark plug into it, it should be tight. This will seal the plug into the coil pak. As they age the rubber gets loose and this will case arcing inside the head bore and you will get a miss. Additionally as mentioned if you get water/moisture down in there it will also cause a misfire. So check them for tightness when you insert the spark plug.

Yes the 1991-94 are different since these years do not have the misfire detection system. The coil pak went from a two pin connector to a three pin connector in 1995 for the misfire detection system. So the early cars cannot tell you that you are misfiring with a code.

HTH,
LarryB

 

[Speedmaster]

Guru could not find a miss. I thought it was a miss, he said it was a slight, very slight vibration at best. I should not be so touchy.

Coil packs came out okay.

Compression came out stellar (all above or well-above 200psi). Leakdown uniform but for one cylinder. May have some carbon/sticky valve.

Replaced injectors with RC Engineering cleaned ones.

O2 Sensor swap was a bust because the one I bought had mashed threads (wish I had looked at the darn thing before relying on it.) Have to postpone that.

Car runs like a top with the injectors.