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S2 C34 Stagea That's Hard To Start

Whooby

By Whooby,
in Four Door Family & Wagoneers

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Whooby Enthusiast

Whooby

Posted
Posted

Hey All,

I've posted about this before without success, but this time I've got videos (Thanks Curt).

The car still has the standard side mount cooler, 3in exhaust, no boost controllers.

I'll list out all the things we've tried and changed/swapped but now we're pretty much out of options.

List of parts changed/tried:

O2 sensor

Coilpacks - now super sparks

plugs - numerous times - cheap and expensive ones

injectors

factory return fuel line reg

fuel filter

fuel pump

ECU temp sensor

CAS

Timing adjustment - advance and retard

AFM

Checked VAC hoses

Cleaned cooler

cleaned throttle body

clean AAC valve - can still be heard opening/closing

Even tried 2 different ECU's

Bigger battery

starter motor

Checked for standard cam's

I think that's all perhaps more but I'll update if I remember.

Here are the videos. theses were all done one after the other

The problem:

When the car is cold trying to start is pretty much impossible without pushing the pedal. The video's pretty much explain it.

The car cranks fine, has plenty of fuel entering the rail but with out pushing the pedal it will never start up. Even once it's running on it's own it's slow and lumpy to get up to the idle speed.

First attempt to start:

Second Try bit of pedal to make it fire, if you listen you can hear the idle pick up slowly. It ran for a couple of mins

Starting again: Inside seeing gauges this time. As you can see once it's running it's very lumpy and sluggish to bring the idle up.

The car runs quite rich, 450k's to a tank is just doable. There is a MiNes ecu in the car currently but this has had no effect, the other 2 ecu's do the same.

When the car is running it's doesn't have any misses, flat spots, it's not down on power, it seems to be getting quicker the more things we try/change. But starting is still crap.

When the car is hot and trying to start is starts pretty much straight away.

That's what I can remember at the moment, feel free to ask questions might jog my memory about something else we've tried.

But basically it's been like this 18mths though all the seasons and we've had just about enough.

Any help PLEASE!!!!!

Cheers,

Hugh

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Whooby Enthusiast

Whooby

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  • Author
Posted

thanks, but tried and failed there. no fault codes. Without knowing what thing's 'should' be it's a little hard.

It was fine one day and then the next morning it went to how it is now. No changes to anything just Bam and its crap.

Tried adjusting TPS made no change.

KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted

See if you can swap out a TPS with someone else.

Is there someone near you with a consult cable who can look at all the inputs from the various sensors? The Stagea manual has all the correct values.

Actually my car has a mystery starting problem where it sometimes won't start unless i pull the lead off the temp sensor for the ecu ( I have replaced the sensor twice). I figure a new engine and ecu should fix it so I am not worrying about it at present.

if you really are desperate I would biff the Mines ecu and get a nistune chip and take it to a good tuner.

ssshonky Grand Master

ssshonky

Posted
Posted

have you cleaned the Idle Air Control Valve? thats the 1st thing I woudl be looking for,

My pulsar used to idle like sh1t until I got that IACV cleaned.

its basically a disc that moves over a hole to adjust air on idle. Its connected to a bi metalic strip.

I can give you a Rough idea of how to clean it. Perhaps just PM me as I might not see theupdate in this thread

do I get a chocolate frog or a gold star if I win?

Whooby Enthusiast

Whooby

Posted
  • Author
Posted

TPS hasn't been tried with a diff one yet, i'll start tracking one down.

ECU temp sensor perhaps, that's easy enough to try.

a nistune wouldn't make a difference i don't think. having tried 2 other stock ecu's i ruled the Mines out as being stuffed or the problem.

QWK32 Veteran

QWK32

Posted
Posted (edited)
have you cleaned the Idle Air Control Valve? thats the 1st thing I woudl be looking for,

My pulsar used to idle like sh1t until I got that IACV cleaned.

its basically a disc that moves over a hole to adjust air on idle. Its connected to a bi metalic strip.

I can give you a Rough idea of how to clean it. Perhaps just PM me as I might not see theupdate in this thread

do I get a chocolate frog or a gold star if I win?

Close, its actually a little plunger that is sealed shut by a spring. a solenoid pulls the plunger back to allow air to pass though to maintain idle. i know the older style separate cold start valves were the same as you describe, i dont think the NEO ones are as they are a long barrel shape. I have been running my car with the cold start valve bypassed for a little while now and don't have a problem with starting and running.

Hugh, thats some really bad luck your having with your car. Do you have access to a Consult setup/software? I know your on the other side of town but if you want i have a cable and software, we could check out what a few of the sensors are doing if you'd like?

Edited by QWK32
ssshonky Grand Master

ssshonky

Posted
Posted

Thanks for the clarification, I have only ever pulled apart and cleaned an SR20DET one , so I thought it might be the same.

am I right that the AAC differs from the IACV?

Close, its actually a little plunger that is sealed shut by a spring. a solenoid pulls the plunger back to allow air to pass though to maintain idle. i know the older style separate cold start valves were the same as you describe, i dont think the NEO ones are as they are a long barrel shape. I have been running my car with the cold start valve bypassed for a little while now and don't have a problem with starting and running.

Hugh, thats some really bad luck your having with your car. Do you have access to a Consult setup/software? I know your on the other side of town but if you want i have a cable and software, we could check out what a few of the sensors are doing if you'd like?

QWK32 Veteran

QWK32

Posted
Posted
Thanks for the clarification, I have only ever pulled apart and cleaned an SR20DET one , so I thought it might be the same.

am I right that the AAC differs from the IACV?

IACV = Idle Air Control Valve

AAC = Auxiliary/Accessory Control Valve

same thing if you ask me just slightly different acronyms. the same valve that keeps the idle smooth and constant also compensates for auxiliary load causing rpm drop e.g Alternator, A/C. So both of those would be a correct description.

On older model nissan i've seen they have 2 valves to control idle, the main idle control, IACV/AAC, and the cold start valve. On the NEO both of these are contained in the one housing, but operate separate from each other, one is electronic and one is coolant operated. if the cold start valve has shit itself on a NEO you will get a really high idle 1500-2000rpm, this has happened to me.

ssshonky Grand Master

ssshonky

Posted
Posted

" I see " said the blind man to his deaf son ..

yeah I must be stuck in Sr20 land cause I always thought they were 2 different setups.

hope whooby gets his car sorted. He needs a Stagea Busy Bee / BBQ / Beer drinking get together.. anyone want to fly me over?

I can drink good !

IACV = Idle Air Control Valve

AAC = Auxiliary/Accessory Control Valve

same thing if you ask me just slightly different acronyms. the same valve that keeps the idle smooth and constant also compensates for auxiliary load causing rpm drop e.g Alternator, A/C. So both of those would be a correct description.

On older model nissan i've seen they have 2 valves to control idle, the main idle control, IACV/AAC, and the cold start valve. On the NEO both of these are contained in the one housing, but operate separate from each other, one is electronic and one is coolant operated. if the cold start valve has shit itself on a NEO you will get a really high idle 1500-2000rpm, this has happened to me.

Mr GTS4 Mentor

Mr GTS4

Posted
Posted

hay hugh if you need to use my consult lead and laptop you know where i live..

we could try my nistune ecu, my tps and temp sensor if you want.. cleaning the iac valve doesn't sound like a bad idea too.

or maybe its just gay ( thats for kim)

Curt

Whooby Enthusiast

Whooby

Posted
  • Author
Posted

Thanks all for suggestions.

Josh - I've got the cable and some diag software. But it doesn't let you change much plus how am I to know what they should be saying? :P

We cleaned heaps of crud out of the AAC valve. Put it back together and it was same same.

Curt - Yeah within walking distance but I'll drive any way :down:

Thanks for the offer, we'll have to take you up on that. Not sure when weekend is looking a bit busy at this stage.

I'll let Kim know.

We're leaning towards something electrical being crap now........

Thanks again.

Hugh.

ssshonky Grand Master

ssshonky

Posted
Posted

Definately not an air leak anywhere hey? a mate of mine got totally confused as to why his car didnt start, turns out there was a dirty great big hole where a pipe SHOULD have gone but didnt ( cause the pipe was no longer needed ) and he forgot to put a bung/cap on the inlet hole

Thanks all for suggestions.

Josh - I've got the cable and some diag software. But it doesn't let you change much plus how am I to know what they should be saying? :P

We cleaned heaps of crud out of the AAC valve. Put it back together and it was same same.

Curt - Yeah within walking distance but I'll drive any way :down:

Thanks for the offer, we'll have to take you up on that. Not sure when weekend is looking a bit busy at this stage.

I'll let Kim know.

We're leaning towards something electrical being crap now........

Thanks again.

Hugh.

Whooby Enthusiast

Whooby

Posted
  • Author
Posted

Checked all the hoses many times. no boost leaks. seems to have an air leak after changing the injectors but hasn't made anything better or worse.

previously no air leaks anywhere.

Changing every hose may fix it, may not.

Timing has always been crap. CAS is current in 'stock' position, timing gun and diag computer say idel is 0 deg. make sense of that !?

timing belt lines up with gear markings.

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