Rb25det - Possible Cas Problem?

[gotRICE?]

Hey Guys, (2nd time i had to write this >: ( dam Vista.. )

Hoping someone can lend me their experience with a problem im having with my Skyline. Sorry for the essay, but i figure the more info, whether relevant or irrelevant makes diagnostics easier!

1998 R33 GTS25t

Stock Turbo

Stock ECU - SAFC2 with mild road tune

3" Turbo Back - decat

FMIC

Apexi Intake

The issue im having, i 1st thought was coilpack related. So i have just siliconed up the coilpacks, replaced spark plugs, put a new coilpack loom in that i had lying around, and cleaned the AFM with CRC AFM cleaner. Then reading i randomly came across a post with similar symptoms suggesting CAS.

What happens, is the car momentarily completely dies. I get no dash lights or anything, i just loose all power. I dont get any pops or spits or farts as if a coilpack had failed or was missfiring, it just wont accelerate.

At lower speeds, like accelerating from 0, with light throttle it FEELS like it misses, but misses on all 6? You seriously feel it and the car decelerates. Almost like if you try to crash start a car and forget to actually switch the ignition on haha. But only for a split second or so, and it does it randomly.

The other thing that happened yesterday was cruising at 100km/h in 5th, id did the same thing, but would not come back to life. Throttle did nothing. Changed to 4th, throttle, notihng. 3rd (getting ready to hit the shoulder now and stop) throttle and nothing. Then as randomly as it stopped, the exhaust gave a loud pop and away it went again. No popping or stuttering again until it came back to life. No dash lights.

All the issues have occurred with light throttle 0-25% possibly a tad more. Boost or no boost.

Today, a cold start. Car was idling away and it suddenly stalled. Started straight away again, idled for a few more seconds and it stalled again.

The rest of the day it ran more or less fine, with the odd hiccup as described above. But nothing major.

Drove into a Nissan wrecker specialist and asked about pricing etc for a new/used CAS. The guy asked to have a listen to it. So popped the bonnet, and immediately he asked me why i had an R34 CAS on my R33? Mentioned the part numbers being different etc and the casing? Had a quick listen with a screwdriver a few revs. Sounded ok..

Can anyone confirm if late R33's share a few common parts with early 98 R34's?

The last thing worth suggesting is that late December i changed the cambelt/waterpump/idler/tensioner etc etc, and obviously had the CAS off.

it was a little difficult to put back in as i'd never done it, so didnt want to force it and possible damage it. Asked the mechanic watching over me to do it. No issues.

Havnt had a single problem up until 2 weeks ago when it would do it maybe once out of every 5-6 times i drove the car. So i would assume i hadnt damaged anything?

Again sorry for the Essay, and hopefully i have provided enough, or too much info for a little diagnostics.

The wrecker even suggested trying going to a local Nissan dealer and get an ECU diagnostic done to see if there were any faults recorded.

Thanks in advance! Fingers crossed.

[GTScotT]

bang things, thats how i found my problem.

was all very similar, then i realised slamming the door set it off, would stall. i kept banging things till i found it to be the ecu. one tap on it would make the car cut out momentarily, just like yours. in my excitement that i had found the problem i banged it a few times too many till it didnt want to come back on lol.

problems sorted now, so i suggest you bang your ecu with your hand and see what happens lol. minor bumps in the road could be setting it off just like mine.

[paulr33]

1998 ECR33 is meant to have ER34 CAS, this is correct

id sounds pretty fundamental your issue

i suspect the main ECU loom is coming loose

unplug the main ecu and re-plug it back in

ensure it clips in evenly and firmly

for every light to go out and die its fundamental

failing that, remove every fuse and reseat them 1 by 1

[paulr33]

if the CAS is f**ked the car would drive like ass and be sluggish

i wouldnt expect every light to go out etc

i cant think of any common issue that would make every light go out and die, other than main ecu loom being loose

[nikki]

I dn't know much about cars at all so what i say may be completely wrong and irrelevant. but i had a car that did the exact same thing. i would be driving normally and then all of a sudden nothing, no power or anything and same thing thru the gears. it happened a few times but then got so bad i couldnt go more then a few meters without it stopping.

Took it to the mechanic and it was the ignition modular... got no idea if the 25's have the same ignition system but yeah... thats wat mine was...

i think i made a dick of myself but if it helps then thats cool.. haha

[nikki]

I dn't know much about cars at all so what i say may be completely wrong and irrelevant. but i had a car that did the exact same thing. i would be driving normally and then all of a sudden nothing, no power or anything and same thing thru the gears. it happened a few times but then got so bad i couldnt go more then a few meters without it stopping.

Took it to the mechanic and it was the ignition modular... got no idea if the 25's have the same ignition system but yeah... thats wat mine was...

i think i made a dick of myself but if it helps then thats cool.. haha

[T04GTR]

not crank angle sensor. for the dash to die it something to do with your battery/alt circuit. i would be checking all the main fuses for corosion.

[gotRICE?]

The dash lights didnt go out when i was cruising, as my HICAS stayed on (light is always on havnt removed bulb since removed unit) and the RPM didnt go to zero. So it would be safe to assume that it still had power?

And when it stalled @ idle, all of the regular lights came up as if i had just switched to Ign. Oil, engine check, SRS etc...

But i will definitely give the ecu plug a play. Check and re-check all the SAFC wiring too.

Will check all the fuses for corrosion too.

Banging the ECU doesnt sound ideal. Might break something else!

Rugby 7's this weekend, so i will report back at some stage on Sunday evening with results or nill results.

[lachlanw]

check your battery terminals and earth strap

[ghostflameR33]

Hey mate i had the exact same issue as yourself last week same day i wwas meant to get a f**kin tune finally lol... changed my plugs and tested coil packs, and igniter. (this is on an rb26). my afm are in good condition. my car would cut out but not stall, have my foot flat on the floor nothing, revvs just die down, and severely misses.

What i found out: the CAS green wire was split and 1 wire out of the braid inside the green was only hanging off it. fixed that. Still had the same issue. I removed the CAS and cleaned it, and put it back on and that fixed the issue. Just check your CAS. I know everyone states it may not be the issue but everyone has different problems for different parts and its usually the most simplest solution to fix them.

[GTScotT]

Banging the ECU doesnt sound ideal. Might break something else!

just try it.... and check the harness as stated above. dont bang the thing like ur trying to break it, just give it a relevant shunt like a good bump on the road would. and try shaking the harness etc.

like paul said its something major, not an accessory based item

[gotRICE?]

Awesome guys thanks for all the suggestions!

AFM cleaner.. is this ok to clean the CAS? Or is it better to leave the inside alone?

[paulr33]

why are u bothering to clean the CAS? i dont see why ? to achieve what?

we all agree the CAS would not cause the issue you are seeing

[MBS206]

A dirty CAS won't cause that issue.

A dirty CAS won't give you any driving issues.

A dirty CAS is only a PITA when you're trying to put it back on.

A stuffed CAS usually has timing jumping, not completely dieing.

Sounds like a wiring loom coming loose.

[paulr33]

agree

whatever is wrong is fundamental and something really bad

ie loose wiring loom or major plugs loose etc

[gotRICE?]

Not sure why i asked about cleaning the CAS.. 7s weekend. Too much drink and no sleep.

Maybe i miss explained it when i said "no dash lights".

What i mean by that is, when you stall a car, you get dash lights. Like, engine check, SRS, HICAS, Oil etc etc.. Same as startup.

When mine was having the problem, i wasnt getting these lights. Thats what i meant. HICAS was still on as mentioned, and the RPM needle was still hovering at the RPM the engine was still turning at.

Went away for the night last night. A good hour or so drive, and a 30min steep windy hill with lots of boost, on off throttle etc. Then alot of cruising. I didnt get one hiccup this time there or back. And i havnt attempted anything new yet :s

I guess all i can do is see if it does it again at some stage and start playing around.

I gave the ECU a few bangs, and jiggle the loom, but nothing. Cars are odd at times.

The only variable has been the weather. When it has been doing it, it has been fairly hot outside. And today, it was alot cooler and didnt do it. *shrugs*

[Skylineboii]

Absolute blast from the past. I'm now having the exact same problem as mentioned in the post. Car will  turn off when driving, no missing or carrying on just turns off like a light switch. If you turn the key off and start it again the car will restart no worries at all. Did you ever find out what the problem was with your skyline?

[gotRICE?]

Seeing as I got the email, I thought I'd respond...

Honestly I don't even remember making this post. It was a decade ago. Lol.  But reading it through, I clearly had no clue what I was doing and was clutching at straws 🤣

 

Sorry I can't be more helpful. Start with the other members suggestions.  ECM loom, battery ground cable, chassis ground etc.  

[PLYNX]

8 hours ago, Skylineboii said:

Absolute blast from the past. I'm now having the exact same problem as mentioned in the post. Car will  turn off when driving, no missing or carrying on just turns off like a light switch. If you turn the key off and start it again the car will restart no worries at all. Did you ever find out what the problem was with your skyline?

What model is your car ? R32 R33 R34 series ?

Sounds like exactly happened to My R33 Series 1

Check the air flow meter and do a search here on re-soldering the connecting pins inside it. 

[Skylineboii]

R33 GTR series 3. Airflow meters seem fine, I've got an Apexi FC (unfortunately) and the hand controller still registers airflow while the car is switched off but decelerating (obviously when the motor stops spinning they read 0). I'm wondering if it could be a ignitor problem? So many possibilities, will have to have a weekend of investigation this holidays.