Major Persistant Issue On R33

[mikeyR33-T]

Hi guys,

since we last spoke about the car, I ended up opting for a rebuild.

Got 'ruby' to do a full rebuild; rings, pistons,conrod bearings, and a few others bits. car has been run in done over 1200kms in her.

But still have a few persistant issues, I would LOVE some honest advice, if anyone has experienced this before?

first of all, on first start in the morning, I will kick the car over, it will idle quite low roughly 500rpm for 5secs and then DIE, unless I give it a touch of throttle, it happens every time I start it for the day - could be cold start. or timing??

Secondly - I am running an r32 actuator on constant 10Psi; I am being told it could be a R&R issue, the situation is at times when cruising or accelerating the rpm will flow upwards while I am accelerating, BUT at times it will feel like the rpm is backing off, or the throttle is backing off when my foot is on the pedal, I am trying to increase throttle but it will back off for a second; this can be on a normal throttle or even on big throttle increase.... and lately the car has been making a HUGE induction sound, like a turbo BUT much louder can be heard from inside the cabin (like a whistle or woooosh)

THE CAR is 1993 R33 S1 - stock turbo, engine, ecu, only mods are FMIC, 3inch turbo bk exhaust & cat, and that R32 actuator...... I have been told a few different answers; it may be running R&R (but why?) it could be the AFM? or TPS (timing)

I have booked in for a DYNO run and for the guy to check AFR levels and see what comp says...... It seems like a never ending issue, and I have no idea where to begin....

AS said everything is basically STOCK - it boosts good around 3-4k not sure exactly, but gets to one point at the top of the RPM and spools up, boosts but then kinda sounds like a backfire, as there is NO BOV! it sounds different??

ANY ASSISTANCE APPRECIATED - AM HOPING THIS NEW GUY WILL FIND THE ISSUE AT THE DYNO!

cheers guys, this is my first import and it means alot to me, just abit frustrating lately

[The Mafia]

Get a new AFM

[mikeyR33-T]

Get a new AFM

Noted but can you explain in detail why? cheers and should it be standard AFM or Z32 (*i plan on going nistune + Z32 ecu in the next few months)

[defari]

z32 afm

r32 ecu you will lose VCT so def go the z32 ecu

Edited February 3, 2012 by defari

[DVS JEZ]

or a rb20 ecu with an eboost to control the vtc switcing points, or ofcourse a rpm window switch.

let us know how it goes on the dyno

[The Dan]

U should wait until the guy with the dyno has looked at it before you go out and start throwing parts at it.

Don't listen to nonsense about R+R, it's the inexperienced mans way of diagnosing every miss fire or hesitation. Your problem sounds like its timing related due to the description you gave about the induction sound etc so AFM would be the most likely starting point but it all depends on how good your description is. Quite possibly a fuel pump also

[Rolls]

What rpm does this all happen at, is it everywhere? Or is it at the typical peak torque point on full throttle of 4500-5500 or is it both.

If it is just the peak torque point then yeah, Id say R&R due to plugs, coils, too rich etc. But if it is happening elsewhere then I believe you have other issues.

[mikeyR33-T]

What rpm does this all happen at, is it everywhere? Or is it at the typical peak torque point on full throttle of 4500-5500 or is it both.

If it is just the peak torque point then yeah, Id say R&R due to plugs, coils, too rich etc. But if it is happening elsewhere then I believe you have other issues.

the rpm/throttle backing off - well its hard to explain, as I said i would be accelerating as normal to drive or overtake and at certain point usually over or around 4k give or take. and then it would feel like the car is literally backing off accel on its own for a second..till i press throttle a lil, almost like a flat spot or a miss (im a total newbie with skylines )

plugs were just checked and gapped by a good friend. and yes I will wait for DYNO, but I like to know others personal experiences (just hope the guy knows his stuff, because previous shop didnt assist or I didnt explain it right?)

Its all a learning curve guys, so bare with me here

[mikeyR33-T]

z32 afm

r32 ecu you will lose VCT so def go the z32 ecu

Oh, also my car is AUTO - been reading something about autos not working with Z32 ecu? or was it R32

[SargeRX8]

My car fails to start first time, most of the time when cold. Read about it skyline starting then stalling on first start, its very very common yet there is no uniform fix. Some say water temp sensor, some say cas, some say tune, some say leaky injectors. I honestly have no idea but I don't care anymore, i'm used to it. I've also got an r33, when you do your reading you will see its mostly r33's that do it.

[Rolls]

the rpm/throttle backing off - well its hard to explain, as I said i would be accelerating as normal to drive or overtake and at certain point usually over or around 4k give or take. and then it would feel like the car is literally backing off accel on its own for a second..till i press throttle a lil, almost like a flat spot or a miss (im a total newbie with skylines )

plugs were just checked and gapped by a good friend. and yes I will wait for DYNO, but I like to know others personal experiences (just hope the guy knows his stuff, because previous shop didnt assist or I didnt explain it right?)

Its all a learning curve guys, so bare with me here

So you have described it is down on power at peak torque, does it misfire (a misfire sounds like a pop, pop, pop) or does it just splutter and feel like it has just stalled?

Does it ONLY happen at 4-5k or does it continue to happen from 4k to redline?

Does it also happen at idle/low revs/low load?

To answer your question of why do I say R&R or why fuel pump or even why cas/afm this is why:

If it happens from 4k to redline and is more of a splutter just no power I am going to say it is your fuel pump that is dying as a dying fuel pump generally provides fairly consistently not enough fuel at all times, this means when > x fuel is needed the car leans out and basically dies in the ass, eg > 4k rpm and it just doesn't have enough fuel to run. This generally won't be a pop, pop, pop but just the car feeling like it is dying and you've taken your foot off the accelerator.

If it ONLY splutters at 4-5k (peak torque) this is when the maximum fuel and air is in the cylinder, this is when the mixture is the hardest to ignite and also the point the ECU makes the fuel as rich as possible. Hence bad plugs/coils (weak spark) and lots of fuel (needs strong spark to ignite) means if the car is going to misfire due to a spark failing to ignite the mixture, it will do so here. Hence why people often find the car misfires (loud pop, pop, pop) at 4-5k but then find the car revs out cleanly to 7.5k. This is usually caused by a combination of bad spark (cracked/cooked coilpacks or old sparkplugs) and overly rich fuel mixture eg 10:1 AFR due to the ECU going to the rich and retarded quadrant of the load map, lowering the boost to stock or retuning this part of the map will fix this issue.

If it seems to happen randomly everywhere and is just generally shit it may be something like a failing sensor eg AFM or CAS as these are usually intermittant and don't get worse dependant on load, they just randomly shit themselves for no reason. Hence stalling, missing at odd revs, down on power and generally all round shit performance. However fuel pumps can also fail intermittently and cause it to stall at idle, and cause the lean out situation randomly.

These are just all general diagnoses, it could be any all or none of the above, and they could all exhibit completely different effects, though generally they will do as I have described.

Note this is important, if it is the fuel pump leaning the car out causing it to die then this is a DANGEROUS situation as it can cause the engine to ping/detonate due to running lean, this will melt pistons and generally destroy your engine very fast so don't go driving it around trying to rev it out over and over again as you may do permanent damage to it.

Once on the dyno it will be very easy to see if it is failing fuel pump, get it there asap. Plugging a consult cable in will sometimes diagnose failing sensors, though unless they completely die the ECU is often unaware that they are giving inaccurate signals.

edit: I can't believe I actually bothered to type all that out, must be in a good mood.

Edited February 3, 2012 by Rolls

[mikeyR33-T]

THANKYOU - I will try to answer to my best ability, but remember my knowledge and mechanical vocabulary is limited

Okay - there is no pop that i can tell, if i take foot off accel it makes a gurgle kinda sound but even my SS did that... its not really a splutter or stall - think of this - accelerating from 0 and rpm going up to say 100km/hr or more... as you are climbing in rpm it will feel like it backs off for a second, not a fluid motion up the rpm, its only for say 1-2secs where it will back off slightly, could be described as a lil flat spot or blockage for a second, usually if i try to accelerate and it does it, I would take foot off and re-apply the throttle to make it move, this is mid cruise as i said generally around 3.5-4.5k rpm and its only for that instance not continual...( JUST like it wont go up the rpm kinda stuck for a second...?) - only remember it happening at the higher rpm range! (AS STATED - it doesnt die, just has a flat spot for a few secs when it should be climbing in RPM it stops for a second but no sound just the feel is wrong and the speedo & rpm gauge drops back a lil...?? if that makes sense!

** CAR HAS ONLY DONE 1200KM SINCE REBUILD, REPLACED ALL RINGS,PISTONS AND CONRODS ***

ALSO - lately I have been getting that super loud induction/suction sound that is very loud like a screamer but It doesnt have one nor BOV....

idle is fine - except the cold start (and yes I have read numerous forums on SAU and it is common)

DYNO - Booked in for MONDAY ) hopefully good news if they pinpoint the issue, but also bad news because more $$$$

thanks again for the advice!!

So you have described it is down on power at peak torque, does it misfire (a misfire sounds like a pop, pop, pop) or does it just splutter and feel like it has just stalled?

Does it ONLY happen at 4-5k or does it continue to happen from 4k to redline?

Does it also happen at idle/low revs/low load?

To answer your question of why do I say R&R or why fuel pump or even why cas/afm this is why:

If it happens from 4k to redline and is more of a splutter just no power I am going to say it is your fuel pump that is dying as a dying fuel pump generally provides fairly consistently not enough fuel at all times, this means when > x fuel is needed the car leans out and basically dies in the ass, eg > 4k rpm and it just doesn't have enough fuel to run. This generally won't be a pop, pop, pop but just the car feeling like it is dying and you've taken your foot off the accelerator.

If it ONLY splutters at 4-5k (peak torque) this is when the maximum fuel and air is in the cylinder, this is when the mixture is the hardest to ignite and also the point the ECU makes the fuel as rich as possible. Hence bad plugs/coils (weak spark) and lots of fuel (needs strong spark to ignite) means if the car is going to misfire due to a spark failing to ignite the mixture, it will do so here. Hence why people often find the car misfires (loud pop, pop, pop) at 4-5k but then find the car revs out cleanly to 7.5k. This is usually caused by a combination of bad spark (cracked/cooked coilpacks or old sparkplugs) and overly rich fuel mixture eg 10:1 AFR due to the ECU going to the rich and retarded quadrant of the load map, lowering the boost to stock or retuning this part of the map will fix this issue.

If it seems to happen randomly everywhere and is just generally shit it may be something like a failing sensor eg AFM or CAS as these are usually intermittant and don't get worse dependant on load, they just randomly shit themselves for no reason. Hence stalling, missing at odd revs, down on power and generally all round shit performance. However fuel pumps can also fail intermittently and cause it to stall at idle, and cause the lean out situation randomly.

These are just all general diagnoses, it could be any all or none of the above, and they could all exhibit completely different effects, though generally they will do as I have described.

Note this is important, if it is the fuel pump leaning the car out causing it to die then this is a DANGEROUS situation as it can cause the engine to ping/detonate due to running lean, this will melt pistons and generally destroy your engine very fast so don't go driving it around trying to rev it out over and over again as you may do permanent damage to it.

Once on the dyno it will be very easy to see if it is failing fuel pump, get it there asap. Plugging a consult cable in will sometimes diagnose failing sensors, though unless they completely die the ECU is often unaware that they are giving inaccurate signals.

edit: I can't believe I actually bothered to type all that out, must be in a good mood.

Edited February 3, 2012 by mikeyR33-T

[SargeRX8]

If your fuel pump is failing, you will get pops, like the car is shitting out self, believe me I know. You can very easily tell the difference between a failing fuel pump and lean pop. If you are losing power without any change from the exhaust sound, ie it still sounds like the engine running smooth, the problem is somewhere else and I would doubt the afm. A failing afm should cause shit idle too.

The woosh sound you hear is interesting too, it could be the cause of all your problems. Have you properly checked and made 1100% sure that you don't have a loose or slipped pipe in your intercooler line anywhere, or anywhere in your intake side? I popped off a cooler pipe, instant slug, loss of power etc but some how managed to idle okish.

try to fix it first without spending money. Start easy, do the stuff you can do and you should be able to fix or pin point the problem to have it fixed. You pay someone to find your problem, you pay big..

You might have an exhaust leak, either head > manifold, manifold > turbo, turbo > dump...

Edited February 3, 2012 by SargeRX8

[mikeyR33-T]

If your fuel pump is failing, you will get pops, like the car is shitting out self, believe me I know. You can very easily tell the difference between a failing fuel pump and lean pop. If you are losing power without any change from the exhaust sound, ie it still sounds like the engine running smooth, the problem is somewhere else and I would doubt the afm. A failing afm should cause shit idle too.

The woosh sound you hear is interesting too, it could be the cause of all your problems. Have you properly checked and made 1100% sure that you don't have a loose or slipped pipe in your intercooler line anywhere, or anywhere in your intake side? I popped off a cooler pipe, instant slug, loss of power etc but some how managed to idle okish.

try to fix it first without spending money. Start easy, do the stuff you can do and you should be able to fix or pin point the problem to have it fixed. You pay someone to find your problem, you pay big..

You might have an exhaust leak, either head > manifold, manifold > turbo, turbo > dump...

thanks - but I dont know anyone with a dyno or computer program to test it, and I have no idea where to look for these parts in the engine, mechanical i have a mate but not computer related!!

[SargeRX8]

You don't need a dyno. To diagnose for exhaust leaks, look for black shit building up anywhere where there are joints in the exhaust system. Another way is a piece of hose in your ear and run it around different joints in the engine bay, if you find an exhaust leak it will sound like a hiss on idle, or louder if its a big leak. Testing the fuel pump; Is the car hard to start? Does it lean pop when on power? The car will kind of turn into a machine gun when you are on boost. If you hear this you either are misfiring or having a lean condition. Either coil packs or fuel pump. Testing for intake leaks can be done two ways, you actually test the intake by charging it with air and sealing it off, or the other way you look for leaks, holes, cracks or anything which looks out of place.

You don't need a dyno to find anything. I have found almost every single car issue I have ever had right in my back yard, and I am a computer science graduate. All the stuff Ive mention isn't skyline specific, its general mechanic stuff.

[mikeyR33-T]

You don't need a dyno. To diagnose for exhaust leaks, look for black shit building up anywhere where there are joints in the exhaust system. Another way is a piece of hose in your ear and run it around different joints in the engine bay, if you find an exhaust leak it will sound like a hiss on idle, or louder if its a big leak. Testing the fuel pump; Is the car hard to start? Does it lean pop when on power? The car will kind of turn into a machine gun when you are on boost. If you hear this you either are misfiring or having a lean condition. Either coil packs or fuel pump. Testing for intake leaks can be done two ways, you actually test the intake by charging it with air and sealing it off, or the other way you look for leaks, holes, cracks or anything which looks out of place.

You don't need a dyno to find anything. I have found almost every single car issue I have ever had right in my back yard, and I am a computer science graduate. All the stuff Ive mention isn't skyline specific, its general mechanic stuff.

I understand what you're saying, but my mechanical knowledge is limited at changing a tyre; checking oil, NO idea on the rest, So i have no choice but to get it dynoed which i wanted anyways

No hiss, no noise on idle itself..unless i de-cellerate then it kinda gurgles! cold start is bad in mornings first thing for the day to start it will idle very low maybe 300rpm for 5secs then die if I DONT give it a bit of throttle..

again no pop when boosting, except right at the end of the boost at high rpm like 6k when i back off after overtaking it will be at the end of the boost and kinda pop once unless thats the noise it makes with no BOV... but thats the only time!

I do recall NOW, that when car is turned on ANYONE can hear clicking noise coming from the dash area for a good 5secs when car is turned to power even before cranking??

I will get dyno for now! I dont trust myself to try to do anything, I have never serviced a car before!

[Rolls]

Sounds like you better take it to a performance shop as it doesn't sound like you can do any work yourself bar change a tyre... so if you can't do it yourself then they are going to have to do it anyway. Might as well get them to figure it out.

If your fuel pump is failing, you will get pops, like the car is shitting out self, believe me I know. You can very easily tell the difference between a failing fuel pump and lean pop. If you are losing power without any change from the exhaust sound, ie it still sounds like the engine running smooth, the problem is somewhere else and I would doubt the afm. A failing afm should cause shit idle too.

A failing fuel pump will cause a lean condition though???

[mikeyR33-T]

Sounds like you better take it to a performance shop as it doesn't sound like you can do any work yourself bar change a tyre... so if you can't do it yourself then they are going to have to do it anyway. Might as well get them to figure it out.

A failing fuel pump will cause a lean condition though??? (I have NO IDEA )

Rolls - I have it booked in mate, just wanted some advice if someone had a definitive answer, I have a good friend who could do mechanical side of things if some1 was to say YES it is AFM for sure.... otherwise a DYNO is the best idea at this point and hopefully it will show if its too lean or too rich or not enough air/fuel.

HOPE they know what they're doing, some places are slack

[Rolls]

Yeah stuff like this is almost impossible to be 100%, even with the car in front of you you can end up swapping a few things before you figure it out. Welcome to the joys of cars, I hope you have lots of money.

[mikeyR33-T]

trueee, well I wanted a dyno anyway to see how the car is after the rebuild, so hopefully it tells me whats happening and if its R&R etc

cheers mate.

p.s will post back Monday night after the dyno

Yeah stuff like this is almost impossible to be 100%, even with the car in front of you you can end up swapping a few things before you figure it out. Welcome to the joys of cars, I hope you have lots of money.