Hard To Start In The Mornings - Rough Idle For 10seconds

[FULOCK]

Hi all,

this question is for my s13 silvia i have just bought as a daily for the next year or so (before a 25 will be dropped in there and turned into a monster!!)

Its a CA18DE - and I cant seem to even be allowed to reply to a thread in nissansilvia.com, and administrators won't answer my emails, so I thought i'd ask the trusworthy SAU forums!!

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When I bought it, there was a little surface oil here and there in the engine bay, so I thought i'd give it a degrease.

now I was carefull to not get water in where its not supposed to be - but I was obviously not carefull enough - so then it wouldn't run for the next 40mins - understandable........

the issue is now.... every morning, the first time I start it up, it will missfire like hell for about 10sec or so, sometimes it will take me upto 3 attempts at kicking the engine over for it to start - then once it gets going its fine again and runs perfect, untill the engine completely coolz down (3hrs or more) and I need to start it again...... before I tried giving the engine bay a degrease it never used to do this - it used to start perfectly every time every morning!!

I've taken out the coil packs and spark plugs and gave them a good clean - there doesnt seem to be any moisture anywhere at all.....

have I possibly damaged a sensor or something??

Sorry for the essay and thanks in advance for any help!!

[Dan_J]

cleaning doesnt do much at all, if your spark plugs are old just buy new ones for 3-4 bux each and see if it does the job

exhaust leak?

Edited February 25, 2010 by Dan_J

[mad082]

could be that when you washed it down the moisture has gotten in somewhere it shouldn't have and even though it may have dried out now it may have caused some damage to a coil pack or something like that.

may also be worth going round with a can of wd40 or something like that and spraying it into any electrical plug you can get to easily. also do a search on here of how to tape up the coil packs. that might be worth trying as well.

[FULOCK]

could be that when you washed it down the moisture has gotten in somewhere it shouldn't have and even though it may have dried out now it may have caused some damage to a coil pack or something like that.

may also be worth going round with a can of wd40 or something like that and spraying it into any electrical plug you can get to easily. also do a search on here of how to tape up the coil packs. that might be worth trying as well.

cheers for that i'll give it a go..... i've had a few people tell me to try reset the computer, just unplug the battery for a few hours.... something to do with the cold start or something?? maybe computer has itself all confused when the engine wouldn't start when I degreased it and since then has locked itself in some sort of wierd state?? dunno.......

car doesnt have an exhaust leak by the way, and new sparkplugs were put in just before I bought the car, approx 3000k's ago, and when I took them out to have a look, they seemed fine, not fouled, not dirty.... etc.

[Dose Pipe Sutututu]

AAC - Aux Air Control unit, give it a clean, it opens up when the motor is cold to achieve a high idle. Seems to be a common point of failure when it gets all dirty.

[bert_]

AAC - Aux Air Control unit, give it a clean, it opens up when the motor is cold to achieve a high idle. Seems to be a common point of failure when it gets all dirty.

not always the case though. it is a common problem. i had the same problem, was fairly hard to start in the morning. the idle would drop pretty low and id have to step on the accelerator a tad before it would jump up to about 2k rpm and then drop to 650. i cleaned the aac valve and it worked for a day or two then it started to happen again. i took the aac valve out to see if it were dirty but it was still fairly clean.

not sure what it is really.

ive tried unplugging the tps to reset idle, unpluged the ecu to reset every thing aswell but no luck.

but thats a good point, give the aac a clean and it might just work for you.

[mad082]

there is actually a cold start valve (not the AAC or IAC) as well (well at least on skylines there is) which can foul up, so might be worth looking at that too.

[Dose Pipe Sutututu]

Well the IAC controls idle and is situated on the side of the plenum (RB20/25s)

and the AAC valve sits in the middle of the plenum and feeds off that fat black hose off the cross over pipe.

Cleaning both of them did the trick for me in the past, and with my RB20 180SX the AAC valve was stuffed and the previous owner blocked it up with a bung, bought another one on this forum for $20 and sorted it straight up.