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Posted: Mon Oct 27, 2003 2:32 am
by Legacy777
I don't know really what the M designation is for.
I don't think the IAC valve would cause that much of a discrepancy in vacuum......not sure.
Posted: Mon Oct 27, 2003 4:05 am
by vrg3
Well, if the IAC valve isn't allowing a proper idle you may see low vacuum as a symptom of a low idle.
12 inches at idle is definitely not enough, but 20 or 21 is about right at 4000 rpm, so you probably don't have a vacuum leak. Even so, you may want to check. You can look for a vacuum leak by spraying starting fluid around the intake while the car idles; it will affect the engine's idle speed if you spray near a leak.
But I thought your car seems to run okay below 1500 rpm?
You shouldn't ever have to adjust the bypass air valve (also called the IAC valve), but it can be done by loosening the two screws on top and rotating the body, and then tightening it back up. If you dare to tamper with it you should at least mark where it was originally so you can return it there if you have to.
Posted: Mon Oct 27, 2003 9:11 pm
by sigkrist
Yeap right it seems to run ok up to 1500 even with this low vacum.
but even with slow trottle it drops vacum after 1500 and up to 4000 down to 4 -5 then after 4000 it jumps to 20 or more. so i really dont now how to handle this problem but hope i can rule out MAP and rest of sensors by borowing somwere.
And another thing i am pretty sure its running really rich and drinking fuel like he got a contract with the oilcompani.
If i adjust Bypass valve then i can get 18 - 19 and more vacum at idle but no chance to increse trottle it just stall if i try..
Well lets say that the car is really getting to my but problems are to solve..right ? so i just keep smiling and try..
If i could get it to computer test workshop it would easy the matters but there are ove 400km to the next one and over few mountains to go on icelandic roads and i dont belive he can make it.
Thks a lot guys
