I've got a 1990 2.1L SI ALB Prelude that's got a rough idle... between 1100 to 2500 RPMS.

Read that air in cooling system could be causing it. Bought spill-free funnel. Trying to burp system but the water gushes out like Old Faithful.

Any Ideas???

By the way...car was sitting in garge for 7 seven years as a result of broken timing belt. That's been fixed and car does run...WOW!!!

 

There's a bleeder nipple in the head most likely. Take a look around the coolant ports at side of the head.

 

Helms manual.

 

Thanks for quick replys. Have opened bleeder nipple when filling radiator until fluid flows continuously without air bubbles. Still get Old Faithful. Read on a different site where it suggests that I should put on radiator cap, leave the bleeder nipple open and start the car till hot and air forced out through nipple. What do you think?

By the way, I've replaced old stuff with new: plugs, coil, air filter, drained 7 year old oil out, put in new oil with filter and motor flush and put in new oil and filter, pressure regulator, fuel injector o-rings-seals-cushions, timing belt (old belt blew 7 years ago and car's been sitting idle until a month ago, cleaned out throttle body...IACV...FITV.

Next will clean EGR. Got lots more to do but for now it getting the air our of cooling system.

 

Id also make sure your injectors are seated correctly and dont have any vacuum leaks.

 

Hi Fellow Luders,

Thanks for the insights. I started up the car this morning and followed a thread that showed the throttle body and two inlet ports/ upper & lower. I closed the lower opening with finger..nothing happened...still idleing up and down. I then plugged the upper port and lo and behold....the car idled down to the space midway between the 1 and hash mark just below it. HELLO!!!!!!

Little bumps in the idle but that's may be due to timing. Got to find that thread again because I believe that port thst stopped the up/down ideling is the IACV. If so then will clean again, install, turn it on and see what happens. I'll let you know the results.

Damn this site is great. I know I've spent a few hundred dollars buying tools and replacement parts and whatnot but it's been worth it.

So thanks again to this point. Take care....drive safe.