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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

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...

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 by 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.

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 =)

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!

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

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.

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.

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.

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?

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