Really stumped .Cam angle sensor replaced but car still stalls

[samuri]

My professional  mechanic who is very enthusiastic about my 1996  RB 25 skyline ER 33 2500cc naturally aspirated engine

The car has done 280000 km.

The motor stops randomly  at times and infrequently. Maybe once a week,once every 3 weeks of short city driving ,

after 100 km of continuous driving or after just  10 km driving!!!

 

My mechanic cant determine the problem  He seems very knowledgable about this vehicle and has one of his own.

He  is a manager at an auto shop.

No rhyme, reason or pattern  why  this problem will occur .

Although the stalling never  happens when the engine is cold

 

The stalling tends to happen more often at the traffic lights when having braked but

it can happen on the highway.The car will not start immediately but if you wait a minute or so,

it will start.

All electrical power is present.

 

The mechanic gave the skyline  a bit of a tune  and adjusted the idle.

It had  a standard 100k service with platinum plugs about 40,000 km ago .

It has had an oil change and filter 1000km ago.

 

The symptoms seemed to mimic a Cam angle sensor problem although there was no back firing .

That was all he could think of .

So  I decided to have the sensor replaced (brand new ) even though he didn't  or push the idea.

That was an Expensive exercise ! $550 for the part

Recently I noticed black exhaust but the can angle  sensor replacement seems

to have made that problem disappear?

why would the black smoke disappear?

 

Anyway, how can I narrow down the problem to determine

the car stalling on the highway and at the lights?

 

All suggestions welcome.

Thanks in advance.

Edited May 3, 2021 by samuri

[robbo_rb180]

Have you checked ecu fault codes? 

Could be iginotor getting hot, fuel pump failing. 

Go through proper diagnosis before throwing parts at it. 

 

 

[samuri]

1 hour ago, robbo_rb180 said:

Have you checked ecu fault codes? 

Could be iginotor getting hot, fuel pump failing. 

Go through proper diagnosis before throwing parts at it. 

 

 

 Thanks robbo,

Yes ECU checked but The age of the car means the ECU doesn't

provide a comprehensive a examination .Fuel pump replaced 5 years ago, however the problem is intermittent.

Wouldn't a fuel pump tend to be more regular with problems .

I thought may have had a fuel problem as well ,so have been using  Fuel doctor.

Ignition coils  replaced with spitfires about 40k ago 

 

No doubt these are legitimate areas to focus on.

Other comments welcome

thanks

[GTSBoy]

56 minutes ago, samuri said:

but The age of the car means the ECU doesn't

provide a comprehensive a examination

Not true. Good diagnostics available out of any Consult ECU. Tell me you got the "no fault" code.

56 minutes ago, samuri said:

Wouldn't a fuel pump tend to be more regular with problems

No. Could be juuuuuuust enough to keep you going and then suck just a little bit too much every now and then.

Hook up a fuel pressure gauge to see what it's doing at low and high loads.

Look for bad wiring connections EVERYWHERE. At the ECU loom plug, at the ECU relays, at the field devices (CAS, AFM, etc etc), at the fuel pump, at the ignition barrel, at the fuse boxes, on the back of the alternator....everywhere. Write a list as you go. Be thorough.

[SteveL]

1 hour ago, samuri said:

Yes ECU checked but The age of the car means the ECU doesn't

provide a comprehensive a examination .

All R32/R33/R34 models have a comprehensive fault code mapping system, which is actually simple to check - do a search.    Fault code check is always the first thing to do.   If the original CAS had been faulty it would likely have tripped error code 11 (universal for all R32/R33/R34 models, I believe).      Replacing the CAS didn't fix the problem suggests there was no error code (CAS OK) and makes me wonder whether they've been checked properly.

Edited May 3, 2021 by SteveL

[robbo_rb180]

if you can get a thermal camera and check the fuse and relays, very handy for diagnosing faulty relays or high resistance issues.
Guessing heat issue in an electrical component.........

[samuri]

I have a thermal  camera. 

How do I know a fault from normal operation ?

Thanks

[samuri]

1 hour ago, SteveL said:

All R32/R33/R34 models have a comprehensive fault code mapping system, which is actually simple to check - do a search.    Fault code check is always the first thing to do.   If the original CAS had been faulty it would likely have tripped error code 11 (universal for all R32/R33/R34 models, I believe).      Replacing the CAS didn't fix the problem suggests there was no error code (CAS OK) and makes me wonder whether they've been checked properly.

I will go back and verify with mechanic  about error codes

[GTSBoy]

1 hour ago, samuri said:

How do I know a fault from normal operation ?

Hotter than looks reasonable. A degree of mechanical/electronic knack is required.

[ossy]

My NA R33 used to have most of the same issues you listed and was waaay slower than it should be but I had a couple of faults all together causing this. Weirdly it didnt show an engine management light or any codes though. Possibly some things for you to look at...

 

First of all I did a compression test for the peace of mind and so I'm not wasting money, which was all good.

The AFM was faulty (wires were corroded) so replaced with another one and fuel pump was also buggered, which was leaking inside the tank so I upgraded to a 255 walbro. 

The TPS and IACV needed cleaning and adjusting.

Also the timing was out (originally thought it was the CAS also) and was all over the place when plugged in... The timing belt itself and tensioners were in a bad state so had a timing belt kit done. Runs spot on now, no problems at all and has all the lost power back.

Edited May 3, 2021 by ossy

[samuri]

18 minutes ago, ossy said:

My NA R33 used to have most of the same issues you listed and was waaay slower than it should be but I had a couple of faults all together causing this. Weirdly it didnt show an engine management light or any codes though. Possibly some things for you to look at...

 

First of all I did a compression test for the peace of mind and so I'm not wasting money, which was all good.

The AFM was faulty (wires were corroded) so replaced with another one and fuel pump was also buggered, which was leaking inside the tank so I upgraded to a 255 walbro. 

The TPS and IACV needed cleaning and adjusting.

Also the timing was out (originally thought it was the CAS also) and was all over the place when plugged in... The timing belt itself and tensioners were in a bad state so had a timing belt kit done. Runs spot on now, no problems at all and has all the lost power back.

Thanks for the info

[niZmO_Man]

I was going to suggest AFM, as that's what I experienced on my car when it got hot (driving in traffic). I have 2!

Search for "AFM solder fix" on here.

[Dose Pipe Sutututu]

On 15/09/2021 at 2:19 PM, Car Accessories said:

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Price on R33 bullbar and van racking please

[PLYNX]

On 15/09/2021 at 2:19 PM, Car Accessories said:

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And a R33 tow bar that has the facilities for a bike rack as well for me please

[GTSBoy]

Is this what you're looking for?

[Dose Pipe Sutututu]

On 15/09/2021 at 3:31 PM, GTSBoy said:

Is this what you're looking for?

This

[PLYNX]

On 9/15/2021 at 3:31 PM, GTSBoy said:

Is this what you're looking for?

Now that's just ridiculous . . . .

 

 

 

I was looking for a bigger boat !

[PLYNX]

On 15/09/2021 at 2:19 PM, Car Accessories said:

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Also a luggage boot rack for a R33 Series 1 please.

The one that will fit over the rear spoiler because I don't want to change the aerodynamic down force by removing it.

[Duncan]

On 15/09/2021 at 3:07 PM, Dose Pipe Sutututu said:

Price on R33 bullbar and van racking please

I hope they have something, I've only seen bullbar kits for 34s in the past. 

[PLYNX]

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We were just getting warmed up !

And I really like that aero package on that 34.

Looks like the aerodynamics of a . . . . . . Lambo . . no no Ferrari  . . .wait wait  . .  Maclaren  . . no no that's not it . . . . ah got it  -  parachute