Fails to start first time

[philboo]

Hi

I hope someone can give some advice. My NSX hasnÂ’t been used much for a couple or years due to personal circumstances. IÂ’d noticed that it was failing to start first time at least two years ago but thought itÂ’s just the battery getting knackered and lack of use. Over the last couple of weeks IÂ’ve actually manage to go out for few runs and have found I still have the issue either cold or hot.

I run the car on shell v power so donÂ’t think itÂ’s the fuel.

It had new plugs about 3 years ago and has hardly been used since.

IÂ’ve videoed it starting up from cold (several days since starting) which you can see here. https://www.dropbox.com/s/d377n05dgo7m925/Video%2002-07-2020%2C%2019%2026%2029.mov?dl=0

It has been serviced by Ben at vtec direct for several years with no issues.

IÂ’d read comments about the master relay but didnÂ’t think this sounded the same. Even so IÂ’ve had that out and re-flowed all the solder joints to be sure. This made no difference.

Can anyone suggest further things I need to check.

Thanks

Phil

[Silver Surfer]

It looks like the fuel is not getting through once the car starts with the starter motor.... Try another master relay.

SS

[NSXGB]

How old is the fuel in the tank?
Have you tried to download any fault codes.
Something odd seems to happen with the ECL when you first try to crank the car - briefly goes out when fuel pump primes, then comes back on, you then crank unsuccessfully. The light stays out like normal the second time when car starts successfully.
I'd guess fuel related.

[philboo]

I’ve ordered one with an ETA of a couple of months. Hopefully that’s all it is then.

Thanks

Phil




It looks like the fuel is not getting through once the car starts with the starter motor.... Try another master relay.

SS

[philboo]

It had fresh V power in April or May but it’s been like this for a while but due to lack of time hadn’t really looked into it. I thought fuel too but wasn’t convinced it was the relay as it’s o predictable to start without issue the 2nd time.

Also, if I switch on the ignition so it primes a few times and then try to start it is happy. I’ve not looked into any diagnostics yet, thought I’d seek advice first.

cheers.

[goldnsx]

Fuel delivery.
Not sure by your description if you tried the following: turn the key several times to IGN and at the 5th time to start. Does it start then? By doing so you build up pressure in the fuel system. If it starts and keeps running you have a fuel restriction: fuel filter or fuel pump or its resistor. The 1st one is easier to replace.
I'm pretty sure it's related not to any electronic problem. If so I'd start with the ignition switch behind the knee bolster. The main relay (or fuel pump relay) shows its weekness while trying to start a hot engine but you've already mentioned that you've resoldered it. But the relay itself could be the problem, so it's not a bad idea to have ordered a second one.
To watch the fuel pressure you could mount a gauge.

[Kaz-kzukNA1]

What is the spec of your NSX?
From the gauge design, looked to be DBW so must be 95+ MT.

Year model, country spec, any modifications, aftermarket security devices, etc?
Anything done around the ECU connectors, behind the seat, ICE devices, etc?
Anything done inside the Eng bay when this started happening? For example, DBW motor connector, sensor connectors, etc?

Please read the error code first.
http://www.nsxcb.co.uk/showthread.php?9229-How-to-read-the-error-code
(http://www.nsxcb.co.uk/showthread.php?9229-How-to-read-the-error-code)
If you set the clock, does it keep the correct time?


In your video, after in P2 ON, the CEL stayed On for about 2sec for the bulb check mode (normal) but it immediately came back On again (00:05 - 00:06) and stayed On for at least another 2+sec (not normal).

Possibly triggered the CEL before starting the engine due to open/short circuit on sensor/device/etc or loss of Vcc or Vref.

It actually stayed On for about 3sec but then you cranked the engine so it could have stayed On forever (not normal).

The engine stalled fairly fast so not conclusive but your TCS light also stayed On after the engine started.
Normally, it will switch itself Off as soon as the engine starts.
However, because it stalled so fast that it may not be able to complete the cycle and could be nothing wrong and not related.


Just before the 2nd attempt when you turned the IGSW into P2 ON, the CEL DID switch itself Off after the 2sec bulb check mode and stayed Off (00:16 - 00:19, this is how it should be).
Then, the engine started successfully and the TCS light switched Off.


From what you wrote, there are several question marks on the IGSW and you could have multiple issues resulting in just one phenomenon so another question mark (but lower priority than the IGSW) on the Fuel Pump Relay, Fuel pump, fuel pump resistor but I'll wait for your answer to the spec of your NSX and the report on the error code first.


Kaz

[philboo]

Thank you Kaz. I’ll look into answering all of these when I get chance.

The quick ones.

it’s a UK 3.0 96 NSX T so I assume DBW.

No electrical changes or work apart from you repairing my climate control a few years ago.

It’s all standard. It had an original alarm which I don’t use but also doesn’t seem to cause issues.

Just standard services, nothing electrical related.

Thanks for taking the trouble to reply.

Phil





What is the spec of your NSX?
From the gauge design, looked to be DBW so must be 95+ MT.

Year model, country spec, any modifications, aftermarket security devices, etc?
Anything done around the ECU connectors, behind the seat, ICE devices, etc?
Anything done inside the Eng bay when this started happening? For example, DBW motor connector, sensor connectors, etc?

Please read the error code first.
http://www.nsxcb.co.uk/showthread.php?9229-How-to-read-the-error-code
(http://www.nsxcb.co.uk/showthread.php?9229-How-to-read-the-error-code)
If you set the clock, does it keep the correct time?


In your video, after in P2 ON, the CEL stayed On for about 2sec for the bulb check mode (normal) but it immediately came back On again (00:05 - 00:06) and stayed On for at least another 2+sec (not normal).

Possibly triggered the CEL before starting the engine due to open/short circuit on sensor/device/etc or loss of Vcc or Vref.

It actually stayed On for about 3sec but then you cranked the engine so it could have stayed On forever (not normal).

The engine stalled fairly fast so not conclusive but your TCS light also stayed On after the engine started.
Normally, it will switch itself Off as soon as the engine starts.
However, because it stalled so fast that it may not be able to complete the cycle and could be nothing wrong and not related.


Just before the 2nd attempt when you turned the IGSW into P2 ON, the CEL DID switch itself Off after the 2sec bulb check mode and stayed Off (00:16 - 00:19, this is how it should be).
Then, the engine started successfully and the TCS light switched Off.


From what you wrote, there are several question marks on the IGSW and you could have multiple issues resulting in just one phenomenon so another question mark (but lower priority than the IGSW) on the Fuel Pump Relay, Fuel pump, fuel pump resistor but I'll wait for your answer to the spec of your NSX and the report on the error code first.


Kaz

[philboo]

Hi

i assume this is the correct information for engine diagnostics http://www.nsxcb.co.uk/showthread.php?9229-How-to-read-the-error-code



Thank you Kaz. I’ll look into answering all of these when I get chance.

The quick ones.

it’s a UK 3.0 96 NSX T so I assume DBW.

No electrical changes or work apart from you repairing my climate control a few years ago.

It’s all standard. It had an original alarm which I don’t use but also doesn’t seem to cause issues.

Just standard services, nothing electrical related.

Thanks for taking the trouble to reply.

Phil

[Kaz-kzukNA1]

Yes.
Can be used for both OBD1 and OBD2 spec.
Yours is OBD1 and DBW spec.
If not sure about the actual code, please take a video from IGSW in P0 Off position and try to include all readings including the volt gauge.

Even without triggering the warning light, it's worth reading the error code at least once a year.

Some of the error codes require two consecutive drive cycles or two detection within the same drive cycle before triggering the warning light.
Therefore, even without any warning lights, still, you may have error code stored on certain controllers.


Kaz

[philboo]

Hi Kaz

I've done the following today.

Inserted diagnostic loop


Car still in my garage, not been started since I previously since put away. See video here: https://www.dropbox.com/s/ii1gm0f6hxes9yv/Video%2005-07-2020%2C%2015%2011%2012.mov?dl=0

Next I removed diagnostic loop and started car (without the issue as if had the ignition on and off a few times for the diagnostic video), drove it for 30 mins


Stopped. Inserted loop and did this video: https://www.dropbox.com/s/zchwvyk0exzj1hm/Video%2005-07-2020%2C%2016%2010%2003.mov?dl=0


Then I removed the diagnostic loop


Tried to start car (from warm having been stopped about 5 mins), it failed with same issue. See video here: https://www.dropbox.com/s/ar93k7gw4pcqwvd/Video%2005-07-2020%2C%2016%2013%2048.mov?dl=0


Inserted the diagnostics loop. See final video here: https://www.dropbox.com/s/68viuzeyqwhsris/Video%2005-07-2020%2C%2016%2015%2034.mov?dl=0

Looking at the diagnostic pdf I think this is showing just the one error code of 4, is that correct ?

Thanks

Phil


Yes.
Can be used for both OBD1 and OBD2 spec.
Yours is OBD1 and DBW spec.
If not sure about the actual code, please take a video from IGSW in P0 Off position and try to include all readings including the volt gauge.

Even without triggering the warning light, it's worth reading the error code at least once a year.

Some of the error codes require two consecutive drive cycles or two detection within the same drive cycle before triggering the warning light.
Therefore, even without any warning lights, still, you may have error code stored on certain controllers.


Kaz

[Kaz-kzukNA1]

That's CEL #40, DBW motor circuit or TH butterfly target/actual positon deviation.
It's not conclusive whether this error was stored in the past or indeed happening at the moment.
If the latter case, very likely to be related to the cause of the engine stall.

Voltage reading seemed to be consistent even during cranking so at this stage, I'll leave power supply related cause out of the scope.


Still, from your latest video, whenever the CEL came back On after the light bulb check mode, the engine stalled so there must be a relationship.


Now that you read the code, the next step is to reset the ECU but please don't do it if you are close to the MOT (6 months extension only applies if renewal date before 01/Aug) or away from your home as there is a chance the ECU may not be able to re-learn all of the co-efficient figures if there is a problem (including loose connector, etc) with the DBW.


Please note that the followings are not the standard reset procedure and only applies to your specific situation.


1. In preparation for the reset process, locate the 7.5A CLOCK fuse inside the pentagonal/octagonal black box under the bonnet/hood.

2. Fully warm up the engine.
Just go out for a short driving or combine the process on your return from outing.

3. Before stopping the engine, switch off the A/C, audio head unit, head light, etc.
Basically, create no load condition in preparation for the next fireup.

4. Stop the engine.

5. Remove CLOCK fuse for 10sec and then place it back.
This will erase all of the error codes from any controllers on the car except for the latest one body ABS brain.

6. Turn IGSW into P2 ON and wait for at least 2sec while keeping eye on the CEL.
Do not start the engine and keep no load condition.
Do not touch the TH pedal.

7. If the CEL came back On after 2sec of light bulb check mode, put IGSW back into P0 Off and then back into P2 On. Otherwise, go to step #8.
Repeat this a few times if the CEL doesn't switch itself Off after every bulb check mode.
This is just to simulate some of your video as the engine always stalled if cranked with the CEL On but then if power cycled, the CEL switched itself Off after the bulb check mode and the following engine fireup was fine.

8. Now start the engine without touching the TH pedal and keep no load condition.
On first attempt, if the engine stalled like before because the CEL stayed On in step #7, go back to P0 and re-start the engine again.

9. Keep running the engine under no load condition and without touching the TH peal for 10 - 15min.
Don't worry about the electrical load increase because of the radiator fan.

10. Stop the engine, wait for a few sec, put IGSW into P2 On and wait for at least 2sec.

11. If CEL came back On after 2sec, repeat #7 and #8 but no need keep running the engine for 10 - 15min. Just short fireup like 10sec is enough.
If CEL stayed Off after 2sec, just start the engine for about 10sec.
Unlike in step #8, the engine rpm should drop to 800rpm almost immediately after the fireup.

12. Stop the engine.

13. Read error code.
If new code or CEL #40 stored, you will need further diagnosis but most likely, loose connector, etc.

14. If no code stored, go out for several outings and remember to read the error code at some point even if you didn't trigger the CEL.
From now on, try waiting for at least 2sec after every IGSW P2 and keep eye on CEL.
On first occurrence of CEL coming back On after 2sec, ideally, do not start the engine and read the error code immediately.


Kaz

[philboo]

Kaz, you're great. My MOT is booked for the 14th July so I'll pause this now until after that. I'll then do the process as you advise.

Many thanks.

Phil


That's CEL #40, DBW motor circuit or TH butterfly target/actual positon deviation.
It's not conclusive whether this error was stored in the past or indeed happening at the moment.
If the latter case, very likely to be related to the cause of the engine stall.

Voltage reading seemed to be consistent even during cranking so at this stage, I'll leave power supply related cause out of the scope.


Still, from your latest video, whenever the CEL came back On after the light bulb check mode, the engine stalled so there must be a relationship.


Now that you read the code, the next step is to reset the ECU but please don't do it if you are close to the MOT (6 months extension only applies if renewal date before 01/Aug) or away from your home as there is a chance the ECU may not be able to re-learn all of the co-efficient figures if there is a problem (including loose connector, etc) with the DBW.


Please note that the followings are not the standard reset procedure and only applies to your specific situation.


1. In preparation for the reset process, locate the 7.5A CLOCK fuse inside the pentagonal/octagonal black box under the bonnet/hood.

2. Fully warm up the engine.
Just go out for a short driving or combine the process on your return from outing.

3. Before stopping the engine, switch off the A/C, audio head unit, head light, etc.
Basically, create no load condition in preparation for the next fireup.

4. Stop the engine.

5. Remove CLOCK fuse for 10sec and then place it back.
This will erase all of the error codes from any controllers on the car except for the latest one body ABS brain.

6. Turn IGSW into P2 ON and wait for at least 2sec while keeping eye on the CEL.
Do not start the engine and keep no load condition.
Do not touch the TH pedal.

7. If the CEL came back On after 2sec of light bulb check mode, put IGSW back into P0 Off and then back into P2 On. Otherwise, go to step #8.
Repeat this a few times if the CEL doesn't switch itself Off after every bulb check mode.
This is just to simulate some of your video as the engine always stalled if cranked with the CEL On but then if power cycled, the CEL switched itself Off after the bulb check mode and the following engine fireup was fine.

8. Now start the engine without touching the TH pedal and keep no load condition.
On first attempt, if the engine stalled like before because the CEL stayed On in step #7, go back to P0 and re-start the engine again.

9. Keep running the engine under no load condition and without touching the TH peal for 10 - 15min.
Don't worry about the electrical load increase because of the radiator fan.

10. Stop the engine, wait for a few sec, put IGSW into P2 On and wait for at least 2sec.

11. If CEL came back On after 2sec, repeat #7 and #8 but no need keep running the engine for 10 - 15min. Just short fireup like 10sec is enough.
If CEL stayed Off after 2sec, just start the engine for about 10sec.
Unlike in step #8, the engine rpm should drop to 800rpm almost immediately after the fireup.

12. Stop the engine.

13. Read error code.
If new code or CEL #40 stored, you will need further diagnosis but most likely, loose connector, etc.

14. If no code stored, go out for several outings and remember to read the error code at some point even if you didn't trigger the CEL.
From now on, try waiting for at least 2sec after every IGSW P2 and keep eye on CEL.
On first occurrence of CEL coming back On after 2sec, ideally, do not start the engine and read the error code immediately.


Kaz

[Kaz-kzukNA1]

Nothing wrong taking the MOT now and as I don't know your circumstances that it may not apply to your case but you could be eligible for the automatic 6 months extension;

Coronavirus: MOTs due from 30 March 2020
Your car, van or motorcycle’s MOT expiry date will be extended by 6 months if it’s due between 30 March 2020 and 31 July 2020.

https://www.gov.uk/guidance/coronavirus-covid-19-mots-for-cars-vans-and-motorcycles-due-from-30-march-2020

Please note the latter part of the above link especially the following sections;

If you take your vehicle for its MOT and it fails;
and

If your vehicle tax and MOT run out in July



Kaz

[philboo]

Hi Kaz

Had the MOT today so then went though the procedure as you advised. I'm now wondering if this issue is just the engine immobiliser part of the original alarm. I never use the alarm but it does immobilise and I have to press a button after I've turned to P2 on the alarm fob which then de-activates the immobiliser. I'm still not 100% convinced this is the cause all the time as I'm sure on one of my P0-P2 cycles I had the immobiliser off and the CEL light came back on.

I've read the code and it was 40 again.

So, I'm still waiting for my master relay to arrive which I'll swap anyway.

I will see how it goes over a month. Thanks again for your help and advice.