R33 Skyline Start Up Problems In The Morning

[Deza3000]

Hey guys, as the name suggest i've been having some unusual start up problems when i turn the car on in the morning. Usually what happens is when i start the car, the engine starts, but struggles to keep the revs high and vibrates excessivly (kinda like a lawn mower running out of petrol), then the car suddenly revs to like 2000rpm and then calms down and idles normally. In some cases when the temperature is cold and i havent used the car for like 1 or 2 days, the car starts, vibrates excessivly, and stalls. Then when i try starting it the 2nd time it works fine. I first thought it might be the fuel pump, or spark plugs but i got the spark plugs changed just last year. There is no symptoms of a dodgy fuel pump so ive ruled those 2 out. All i can think of is a dieing battery, but the car starts normally during the 2nd start so not sure what it could be.

Additional information: Sometimes when i start the car, and it struggles to start, i tap the accelerator lightly for barley a millisecond and the engine will suddenly start up and everything is normal.

Cheers in advance guys

[MatthewT85]

its exactly the same sort of problem i have, but for me it has started after i changed my fuel pump to an 040,

did a bit of reading and people have said to clean afm and the aac valve i think its called, i havent tried it yet

been a bit lazy...

[Deza3000]

Ill give it a shot tomorrow, hopefully it gets it starting up normal again. But if it is the aac valve, wouldnt the general idling of the car be dodgy as well?? Cause aac valve controls idle's i believe and my car idles fine but starts up bad, i could be wrong though. Ill give it a shot either way. Cheers

Edited July 15, 2012 by Deza3000

[dyl33]

When you start it (cold start morning) does the rough/lumpy/shit idle sit at 500rpm for a few seonds, Then goes up to 1500-2000rpm and it's fine?

[Deza3000]

When you start it (cold start morning) does the rough/lumpy/shit idle sit at 500rpm for a few seonds, Then goes up to 1500-2000rpm and it's fine?

Hey dyl33, Yes what you described is exactly what happens! in some cases it stalls but yes thats pretty much whats happening.

[dyl33]

I'm not sure what is causing it, I've got brand new fuel pump/filter,afm,coil packs/plugs, So I can rule them out, Going to clean aac valve and go see my mechanic. I think it only started after really cold mornings.

[Deza3000]

Yea must be the aac i guess, ive read some forums and people have seen positive results when cleaning their aac. Maybe its just a r33 problem, my mate who owns a r33 also has dodgy start ups in the morning, mine however seems to be getting worse. Ill try putting in a new battery as well, see if that helps. Cheers for your input =)

[dyl33]

I'll let you know what my mechanic says this week,

[Deza3000]

That would be really helpful! Thanks heaps mate =)

[hamiltonau]

Happened to mine for ages, went to a mechanic last week (Uas in western Sydney) and he found a few leaks in the rubber hoses around the engine.

Lol don't ask me which ones or what they were connected to.

He plugged the leaks and now no idle issues at start up or ever!

[drunkn snail]

I get the same problems in the morning if left overnight, think its pretty common, only thing I'm concerned about is not building oil pressure while it struggling

[Deza3000]

Yea thats my problem, but there should be a valid reason why they struggle so much every morning on start up =[

Mine is really bad now, it just stalls.

[dyl33]

mine stalls first time, unless I push the throttle before

Havn't been to the mechanic yet. Have you had any new findings Deza

[OEM_as_f*ck]

Hey guys

90% of the time these problems are the idle control valve.

When you first start it in the morning, the ECU runs the motor a little rich for a few minutes, like a choke on a carburetted engine. This improves cold starting and idles the motor a little higher to help build oil pressure and warm the motor quickly. If the idle control valve is blocked or not opening correctly, less air will enter the engine. Not enough air combined with the already rich fuel mixtures means that the engine is simply going to run like shit until the choke is cancelled either by you blipping the throttle or by restarting the engine.

Hope this helps

[Deza3000]

mine stalls first time, unless I push the throttle before

Havn't been to the mechanic yet. Have you had any new findings Deza

Its better than it was before, i did the same thing you did and pushed the pedal before it stalls. Seems to start up fine that way. Still would be better if i could start it up normally without any problems.

[Deza3000]

Hey guys

90% of the time these problems are the idle control valve.

When you first start it in the morning, the ECU runs the motor a little rich for a few minutes, like a choke on a carburetted engine. This improves cold starting and idles the motor a little higher to help build oil pressure and warm the motor quickly. If the idle control valve is blocked or not opening correctly, less air will enter the engine. Not enough air combined with the already rich fuel mixtures means that the engine is simply going to run like shit until the choke is cancelled either by you blipping the throttle or by restarting the engine.

Hope this helps

Cheers, ill try cleaning it, i wasn't very keen on doing it myself, might just pay a mechanic to clean it for me.

[dyl33]

I'm awaiting my new AAC valve gasket, Then ill give it a clean. See how that goes

[Deza3000]

I'm awaiting my new AAC valve gasket, Then ill give it a clean. See how that goes

Hopefully that cures the problem, if not then it really is a mystery. Ill give it a shot as well, Might have to purchase a aac gasket from ebay. Ill try find a walk-through of how to remove the aac valve.

[Deza3000]

Found a DIY on cleaning the AAC valve. Hopefully this does the trick

http://www.skylinesaustralia.com/forums/topic/110431-diy-aac-valve-cleaning-idle-reset/

[tripsteady]

Hey guys

90% of the time these problems are the idle control valve.

When you first start it in the morning, the ECU runs the motor a little rich for a few minutes, like a choke on a carburetted engine. This improves cold starting and idles the motor a little higher to help build oil pressure and warm the motor quickly. If the idle control valve is blocked or not opening correctly, less air will enter the engine. Not enough air combined with the already rich fuel mixtures means that the engine is simply going to run like shit until the choke is cancelled either by you blipping the throttle or by restarting the engine.

Hope this helps

so is this the definitive cause? would it also be leaks as suggested?