I need help guys ???
Lately, when my engine gets warm, (Just starting to get around the N O R M A L range on the temp guage), the negine starts to rev, when the transmission shifts to first gear (Auto).
At first I thought this was a transmision problem, but now I am not so sure ???
I started shifting the auto trans to Nuetral, when I was slowing down, and realised that around 10Km, the engine revs out to around 2500 rpm for no apparent reason.
I am suspecting that it is caused by the Idle speed controller, or has something to do with the Carbon Canistor Purge, but again, not too sure. (The manual says that Canistor purge happens when the engine temp is normal, and there is no load on the engine ??)
This problem has only really started recently, and although I dont think its got anything to do with the cam, I am not 100% sure ???
Has anybody here experienced this problem ???? Or have any idea's what might be causing it ????
I am thinking of doing an ECU self test tonight, when I get home, but was just wondering what the problem could be ???
Any help would be greatly appreciated !!!
Thanks for your reply EF_Falcon_Guy.
It takes about 3 seconds to return to idle.
If I start the car with the aircon off, it starts straight away, no problems.
If I start with the aircon on, it starts immediately, but the idle does a bit of mucking around, (revs out to about 1500, then down to 600, then back up to 1000, then down to 600, then up to 700, where it will sit comfortably for a while).
The above only happens when the engine is warm, (I.E. driven recently), but everything starts and runs fine when it is cold ???
Its starting to get on my nerves as well, as when the transmission is in drive, and I am slowing down to a stop, the thing accellerates, when it shifts into first.
Also, driving around shopping centres, dropping the speed below about 10Km, makes the thing accellerate.
When this happens, I either lock the transmission in first, to stop this, or drive at about 15km (A bit too fast for shopping centres though).
When the engine is warm, I can make it do this at least 95% of the time ????
It was actually doing it a little bit before the cam mod, but only when the car was stopped. (I.E. I could be at the lights for about 30 seconds, then the car would rev to 1500 or so).
First time it happened, it scared the crap out of me, as I was resting my foot on the brake, (Not holding it hard), and the car jumped forward a couple of inches !
My first reaction was that someone had rear ended me (Lol).
The above symptoms have been happeining in the last week.
I must admit, that I have not been gingering the car, since the cam mod, so I am not sure If I have stuffed something, or the ECU is trying to re-learn some parameters, that may be out of range ??????
Yeah, I would have to agree 2500 is very high (It goes this high when in Neutral)
When the car is in drive, it will rev out less than this, (I guess because the engine has a load or something), I would say about 1500rpm.
The jump in RPM is enuf to actually make the car jump, or look like an "L platers" Kangaroo hop. (Which makes me look like a real goose - well more of a goose than I look normally :crazy1: )
EF_Falcon_Guy - Your simptoms sound very similar to mine, with the exception that you dont have it to the same EXTREME as mine, which makes me think that it has nothing to do with the Auto Transmission, (Which a few ppl have toldme it was originally), although I could be very mistaken ????
My car has a similar tendency. I believe the computer sees a low road speed reading, low manifold vacuum (caused by the cam of course), and low revs. It becomes confused and bumps the idle up to compensate. This is done by inputting more 'steps' into the IAC Valve.
It seems unusual in that mine will hold the revs and then allow them to return to a normal idle speed. Essentially mine is similar the BMWs etc where this is called an 'electronic flywheel'. It is programmed into many ECUs to aid in emissions during decel (lowers the NOx levels).
My suggestion is to disconnect the IAC connector and see what happens. You will create a code, however it won't matter after you reconnect it. If this stops the problem you have a fault path to chase down. I am unsure if the car will stall etc, however keep aircon off to keep loads down at idle.
BA'1.5' Pursuit 290
Lightning Strike / Reflective Orange Stripes 'General' Dog - AP's German Shepherd and Best Mate - 02Dec1998-15Dec2003.
'Pepper' Dog - General's and My Little German Shepherd Sweetie - 1996?-02Apr2006. 'Sako' Dog - My Beautiful and Pretty German Shepherd - 2001?-23Aug2006.
Pete how high does yours idle upto??? I thought the isc had preset values for everything ie. to control idle it will open to a preset amount then adjust timing to get correct speed. I didn't think the V8's had any sensors to detect low manifold vacuum. You problem could be that your engine is now more sensitive to throttle positioning after your mods, less throttle more revs and gets there quicker. Just a thought, see what the other think (Pete, Kon and the likes would have a better idea)
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