okay guys to give u insight on my knowledge here i'm a domestic nut and my g/f has a 91 accord...the car runs fine and is a damn die hard(go figure)...only thing that drives me nuts in it is that it will idle at a "normal" rpm then rev up and fall back down...and when it revs up it's very shaky...any ideas to this welcome

 

well, it could be a variety of things...

for starters, check the coolant level...the iacv (idle air control valve) has coolant running through it to adjust the idle according to engine temperature...if coolant gets low and stops running through the iacv, or gets an air pocket in the iacv, the problem that is occuring with your car could happen...the iacv could have also gone bad, or need cleaned...there is a screen inside of it that you can check to see...

second, make sure that you don't have any CEL's...this would cause the motor to idle high (usually 1500 rpm's) if the motor is in limp mode due to a code...sometimes it will idle high and fall off like in your case...

third, make sure that somehow a vaccuum hose has not come off somewhere on the intake manifold...also, check for holes in your vaccuum lines on the intake manifold...


also, could yuo give is a more accurate description of what you mean by shaky when it revs up...this could be anything from a motor mount to a balance shaft to internals gone bad...

 

okay i read what i wrote...if the car is hot cold whatever u are sitting and idleing and the car seems to "sink" fall on itself and then the car shakes and revs back up and its a very.....non-rhythmic cycle....if the ac is on then it shakes even harder

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mean_1 &raquo;</TD></TR><TR><TD CLASS="quote">okay i read what i wrote...if the car is hot cold whatever u are sitting and idleing and the car seems to "sink" fall on itself and then the car shakes and revs back up and its a very.....non-rhythmic cycle....if the ac is on then it shakes even harder</TD></TR></TABLE>

oh, just adjust the idle up a little bit...sounds like it might be set too low...

 

i have the same problem with my 1991 accord that i just purchsed. i got it for a good deal and know that the engine needs a lot of work. my car has exactly the problem u mentioned. I recently changed the rad and it still does it, as well the dude that had it before me put an air intake on that i still suspect has a hose that might be unplugged but I'm not 100% sure, there is one hose hanging that is unplugged, i have never put an intake on , and dont know if one should be left cut and unplugged , but i plugged it with a screwdriver bit , and the problem was still there so i took it off. i am waiting on some prices to get 3 of my 4 cylender rings changed. i hope its only the rings , but i think this car was greatly neglected so im expecting the worse when the head is removed.

my compression tests were way off with readings at 210-160-160-105

i dont know exactly what causeis this problem but its annoying, sometimes it feels like the engine is gonna die, then it sputters back up, almost shuttig off.


I would like to know some opinions if it is a better idea to rebuild my engine or get one from a similar year swaped in? i've been getting mixed responses on this, some telling me that if its just the rings its fine , but if they walls have to be bored due to wear then its better to go with a swap, ?

thanks
john-bong

 

adjust the idle on the throttle cable....whats the MOST it should be at?