eesuh

so i got a 92 eg yesterday and it had no exhaust system. as i would be at a stop light the engine would rev itself lightly every second or two. now i talked to one of my friends and he said he thinks it was doing that because there was no exhaust. he said when theres no exhaust the engine doesnt get a certain amount of pressure its supposed to get from the muffler thus causing it to rev itself. is this correct or is the reving caused by something else? if anyone knows please fill me in, thanks in advance.

eesuh

bump, anyone?

eesuh

someone gotta know? anyone?

cehcivic15

no, you need to make sure there is no air in the coolant system, bleed the system to make sure, is there a check engine light?

eesuh

no there is no check engine light

cehcivic15

ok, so you can cancel out the idle air control valve, you need to get all of the air bubbles out of the system

eesuh

ok ill look into and get back to u, thanks.

instructor74

some back pressure is need on the engine. I don't think however that that is your problem. Does it rev up and down all the time or only after it is warmed up? It could be a dirty/bad iacv (idle air control vale located on the back of the intake near the tbody) If it reves all the time. If it only revs after warm up then it is more then likley the fitv ( fast idle thermo valve located right under and attached to the tbody) An easy test for this one once the engine is warmed up remove the intake at the tbody look inside the tbody you will see 2 small holes cover the bottom hole with your finger if you feel a vacume the fitv is in need of service or replacment

instructor74

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cehcivic15 &raquo;</TD></TR><TR><TD CLASS="quote">ok, so you can cancel out the idle air control valve, you need to get all of the air bubbles out of the system</TD></TR></TABLE>
I wouldn't cancel out the iacv yet just because there is no code does'nt mean that it is not the problem. Never had a code with mine cleaned it up and the surge went away

cehcivic15

i dont think the iacv is it cause no check light, what you have is a hunting idle, it could be the fitv, but always start with the simplest solution

instructor74

again you don't have to have a check light for the iacv to be the cause. however if its happening to him at stop lights the car is hot and it is more likley the fitv

cehcivic15

well that might be true then....if you do clean your iacv, then make sure you spray some lube in there afterwards because your carb cleaner will dry out the rubber inside the iacv

perseverance

only time u get a check engine light from the iacv is when it's disconnected. if its connected and hanging somewhere...or not operational..no code will be thrown.

cehcivic15

OK i know that one is false...........haha