My car has Gremlins and its frustrating! Almost had enough!!

To answer a few of the questions:

I bought the AEM FPR from Science of Speed. There was no option of changing the orifice out....not even sure what that is. There is a screw on the side to change the fuel pressure. I'm fairly confident that this is not the issue.

The TCS was disconnected when I was having the problem, so I'm pretty sure that you can eliminate the TCS in the troubleshooting. I forgot what the clicking was coming from, but it's right there next to the TCS I think. It's been a long time since I had this problem.

And like Jetpilot says, this isn't something that you can just "replicate", which is what makes it doubly frustrating. It just happens when it wants to.....the only constant for me was that when it decided to happen, it was a little over 3000 RPM. For me, it would go for a week without happening, and then all of a sudden it would happen several times in one day. As a matter of fact, it went for a LONG time without happening, because I thought that I had fixed the problem when I swapped out the ignition relay.
 
Viper Driver said:
To answer a few of the questions:

I bought the AEM FPR from Science of Speed. There was no option of changing the orifice out....not even sure what that is. There is a screw on the side to change the fuel pressure. I'm fairly confident that this is not the issue.

.
Click to expand...

May I ask a little history question:)?? Did this start after the Walbro was installed? Why did you change the fuel pump, did the original fail? How many miles on the car?

Regards,
LarryB
 
First make ablution and pray for the car its possesed by Jinn(devil):biggrin: .

Second push the passenger seat forward, open the plastic facia covering the DMU and check to see if its loose. I have had my share of electric problems on German cars so speaking from experience.... I have heared of some cars computer being loosing causing electric problems. Is the main engine ground and other grounds fastened throughout, I am asking because you did a face list etc. You may start unplugging wires to see if you can isolate the problem such as door lock motors, windows etc..

Larry is the man follow his command.

Good luck
 
Larry Bastanza said:
May I ask a little history question:)?? Did this start after the Walbro was installed? Why did you change the fuel pump, did the original fail? How many miles on the car?

Regards,
LarryB
Click to expand...

Yes, the problems happened to start after the pump was installed, but it was a while afterwards. I did a lot to the car in the years and months before the problems started, including the SOS Stage I stuff (ECU, big-bore throttle body) and a myriad of other stuff, too.

I changed the fuel pump after some tests indicated that the current pump was about to fail (wasn't holding pressure). Since I had planned on going with some type of power-adder one day (CTSC) I wanted to make sure that the fuel system was going to be able to handle the increased demand for gas. I never got to put a CTSC in, but the car was running great with all of the new stuff. I didn't just do all of this on a whim....I was talking a lot with Chris @ SOS during all of this, and I went with his recommendations.

The car had about 63K on the odometer when I handed the keys over last summer...I'm sure it can't have too much more than that now!
 
Larry B,

There are 66,000 miles on the car and Chuck can answer you on the history of the Fuel Pump.

Others - The TCS is connected at present and the issue happens so we've deduced that this happens with or without the TCS connected. Just to make sure I'll disconnect the TCS completely this evening as its pointless anyway (many recommendations from Primers to disconnect it).
 
Viper Driver said:
To answer a few of the questions:

I bought the AEM FPR from Science of Speed. There was no option of changing the orifice out....not even sure what that is. There is a screw on the side to change the fuel pressure. I'm fairly confident that this is not the issue.
Click to expand...

You're fuel pump/connections could be bad.
The orifice on the AEM FPR is the part where the fuel return line attaches to. If you go for a 255lph fuel pump you have to change to a bigger orifice (supplied with the AEM FPR) as more fuel has to be returned to the tank. With the small orifice the engine gets too much fuel and pressure. That's purely theoretical (ok, by AEM recommendation), so someone could explain some evidence on the NSX.

BUT:
I don't think this to be the problem to look at first and I don't want to send you a wrong route but to keep in mind. I still think it's electrical. Starting with deactivating TCS is one way to go. In the meanwhile you could clean the battery connections and all grounding cables and check other things mentinoed above.
 
goldNSX said:
I still think it's electrical. Starting with deactivating TCS is one way to go. In the meanwhile you could clean the battery connections and all grounding cables and check other things mentinoed above.
Click to expand...


I agree, any wires, plugs, aftermarket stuff reversed or hooked up backwards?
 
goldNSX said:
It's 4k rpm where the fuel pump relay gets active. For a test drive you can take off the panel directly under the glass to the engine. On the driver side the relay is screwed to the chassis, it's black about 2x1 inch. Take a passenger with you who locates the clicking (by touching or whatever). One question: When you hear the click of the relay, does it click 'wildly' or only one time. How does your car shake? Alternating revs? This would result in more than one click if the revs always pass 4k rpm. If you shortly loose voltage it will click more than one time too.

One question: Your car has the 255lph Walbro pump which delivers more fuel than necessary. Which orifice did you choose on the AEM regulator?
Click to expand...

Issue #1 is solved! Changed both fuses today and both A/C Condenser fans worked perfectly and the car stayed cool when idle.


Issue #2:

goldNSX,

This evening I went for a drive with my mother (yeah laugh now she's visiting me in Dubai and handy to use for diagnosis).

I removed all of the panels behind the seats and had my mom listen to the clicking noises happening. When I turn the ignition on there is a loud audible click (single click) coming from the Mitsuba Rectifier Controller (black box directly behind the drivers seat next to the TCM Module).

Now, when the main issue happens and the car is at 3,000 rpms in 2nd gear, the car shakes violently, CEL light comes on, intermittent power loss, this audible clicking noise happens once or twice.

Interestingly enough we went for a drive and in 1st gear revving the car from 3500 - 4500rpms with no audible clicking. Do this in 2nd gear and push the pedal hard and you hear one audible click at 4000rpms and another at what seems to be 4500rpms. Do this again with a gradual increase in revs and no audible clicking noise happens. If I try this in 3rd gear it doesn't happen either.

What does the Mitsuba Rectifier Controller do?

It strikes me as interesting that this audible clicking is happening when I turn on the ignition and when the car is in 2nd gear (exactly when the main issue happens and in no other gear).

Thanks for the help!

Jetpilot
 
I only here a clicking noise behind me while in 4th gear if I floor it no other gears that I am aware of. larry is right some kinda speed sensor. Usually clicking noises are related to relays.
 
Oh to add...

I completely disconnected the TCS as well and the drove fine and the audible clicking happened as described above.

Tomorrow I'l purchase a volt meter and test the TCFC as per the manual. Once that is tested we'll see what the results are. Next, I'll unplug the battery or pul the clock fuse to clear the error code and drive the car until the issue happens again with the CEL.
 
Could be a bad relay on its way out, start replacing these if they are not expensive until you can isolate it. Keep us posted this is good info.
 
Good to know that one problem went away.

@#1: Did you buy the multimeter already? As you've dismounted all the stuff behind the seats you can plug it to the fuel pump relay and read the voltage (NOT the current!) while the revs are between 3.5 and 4.5k. This should work even while your car is standing still with of without any gear. You should see a voltage change at 4k rpm. See SM page 11-101 for location.

But again I'm not sure if the multiple clicking of the fuel pump relay is the cause or the symptom. As you got error code CEL 36 I'd start with page 19-102 to 19-104. As the problem is intermittent please be patient with the results. Good luck!
 
Jetpilot3 said:
Oh to add...

I completely disconnected the TCS as well and the drove fine and the audible clicking happened as described above.

Tomorrow I'l purchase a volt meter and test the TCFC as per the manual. Once that is tested we'll see what the results are. Next, I'll unplug the battery or pul the clock fuse to clear the error code and drive the car until the issue happens again with the CEL.
Click to expand...

Too late for my post. :wink:

From your list above I'd do these test first, in this order:

So here's what we know:
4. Checked Battery Terminals this evening for connection tightness and if they are clean and a okay

-> CLEAN THEM REAL GOOD, ALSO check the grounding cables, take them off, watch out for corrosion, spray and clean them with electric cleaner, one in the engine bay to the front cylinder head and one in the front to the battery.

3. Error Code comes up with 36 (3 slow flashes, 6 quick flashes) and now I need to purchase a voltage regulator to test the connection or connectivity between the TCS Control Unit and the PGMFI ECU.

-> I'd pull the fuse first and clear the memory, go for a drive and pull the code again, if it's still there and the car didn't shake code 36 doesn't have to make your car shake. If the car didn't shake and no error is recorded, go for a drive until it shakes and pull the code. If it's 36 again you have a very high correlation that this IS the cause. Of course you can do the check according to the manual first.

2. Main Relay - > check the connectors at the main relay

-> watch out if they're clean

...
Check out these things above first, then the following
...
4. Suggested by Drew - I can't remember, but doesn't the fuel pump switch voltage at 3K, that relay might be unhappy. You can jump the relay to have it at high voltage all the time to see if it changes the behavior. Interesting that two people have suggested the Voltage Regulator.
5. OneREDNSX suggests checking the connector for the Fuel Pump Resistor
6. Spark Plugs and or their gap is suggested to be checked

EDIT: Just read that you're going to buy a multimeter. Please take also an electric contact spray. :wink:
 
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This may be a long shot, but the two problems may be related. Fuses do not blow unless the current exceeds the fuse nominal value. (even for just a moment in time.)

If the car's nominal voltage is not constant, either is the current to loads. The Alternator generates AC and is converted to DC and regualated between 11 -14 volts. If you have issues with your alternator, then the entire electrical system can experience odd issues.
Tune your AM radio off station and listen if you receive engine noise. If you do purchase a voltmeter, see if you can find one that records peak highs and lows. connect it and monitor over a period of time. Measure the AC value at the battery. If you have diodes blown, AC will be getting to the battery and the rest of your electrical system. Unexpected results will be hard to determine why odd issues exist.
 
I don't have anything of value to add, but I will say I'm seriously impressed (again) by the knowledge and helpfulness of Primers. Good luck JetPilot.
 
Just crossed my mind. Does the car have any paint work. I had Bmw M3 that was painted near the engine ground and after many months of normal driving it just starting bogging out and eventually stop starting all together. Took it in for code check and dealer got DMU code. He hand sanded(duno with what:)) to clear the contact and clear the ground. I would never been able to guess this on my own. Start looking for paint near wires.
 
@warrenw: Good point but I recall of several other NSX's which had blown fan fuses and no other symptoms. These seem to be weak but of no relevance in this scenario IMO.

With the multimeter one can switch to AC and see it there is any AC voltage from the alternator. But I still believe that the problem is not an over-voltage one but more a LOSS of voltage during a small period of time.

@NSXFRIEND: Good point. These are the grounding cables to look out for. 1st pic: between battery and chassis 2nd pic: the cable is on the left between the chassis and the cylinderhead cover. I recall two of them, any other to look at? I'd take them off and clean them anyway, just to be sure.
 
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Liquid said:
I don't have anything of value to add, but I will say I'm seriously impressed (again) by the knowledge and helpfulness of Primers. Good luck JetPilot.
Click to expand...


Its frustrating to see a fellow primer not having his car running in top shape. These cars are pretty much vise free:biggrin: and should be, there is only a few possibilities of causation.

nsxgold thanks for the photos i will also take a closer look at my car.
 
Hi Everyone,

Not posting any results as I'm waiting until Saturday to work on her. I'll post what happens afterwards.

Cheers,
Jetpilot3
 
Okay haven't done anything yet but I have purchased a multi-meter. However, the car is back to my mates shop to have the rest of my Type R +02 conversion installed.

As I started up the car she idled at 500rpms then up to 1000rpms then back down to 500rpms, then back up to 1000 rpms, and did so for 2-3 minutes! Once I drove off there wasn't any issue all night long (to my mates shop).

Any ideas what would cause the revs to undulate like that?

Anyway once she's back from the shop next week I'll proceed to start working on this issue.

Cheers,
Jetpilot
 
Weird question: You're running non-stock wheels - what are the tire sizes?
are they correct for the ratio of front to back?

The issue COULD exist because you're causing the TCS to freak out when it notices weird "slippage" that isn't real.

Did the previous owner put those wheels and tires on the car?
Did the problems start shortly after?
 
Red,

Can't see it being the wheels as they run in the % tolerance compared to stock (I think). Regardless the issue happens even with the entire TCS disconnected...
 

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