Idle bounce's up and down
Moderators: RedRacer, spiffyguido
-
spiffyguido
- Moderator
- Posts: 2196
- Joined: Fri Nov 11, 2005 2:55 am
- Prelude Model: 1991 SE-SR
- Location: Alberta, Canada
- Contact:
-
redlude
- Prelude Enthusiast
- Posts: 9
- Joined: Tue Feb 19, 2008 5:32 pm
After replacing both units of the IACV system, still no luck.Have replaced cooling fluids, thermostat, ect..Still cant get car to idle steady and idle down below 1200 rpms.This car is a bear to drive and I am getting close to calling it done.Have had it to 3 different dealers, and 2 auto repair shops ($267.00 in estimates).all said same thing, but after $391.05 in just IVAC parts and no fix, I am thinking their may be a prelude for sale soon.I rely on this car to get my new 7 month old son to places, and i am starting to think it would be better to just find something that already runs with less headache.Any last ideas will be much helpful, before retirement.
-
spiffyguido
- Moderator
- Posts: 2196
- Joined: Fri Nov 11, 2005 2:55 am
- Prelude Model: 1991 SE-SR
- Location: Alberta, Canada
- Contact:
That's all very dissapointing. You must have a very special case going on here.
There are a lot of systems that control the idle. It sounds to me like you've taken car of any and all of the obvious ones.
Let's review:
Coolant: Make doubly sure that there is no air in your coolant lines. Best way to be sure of this is to bleed the coolant when the front of the car is elevated slightly. If there is any air in the system, there's a chance it could mess with the IACV system.
IACV: You have a new IACV, so you shouldn't have this problem, but make sure that plunger is in place.
Vacuum Lines: Check for leaks. Using soapy water in a spray bottle works well for this. Spray the hose, and if you see bubbles, forming up in a place, you have a leak. Be thorough as vacuum line leaks are hard to find.
Idle: I'm starting to think this may be part of your problem. If you idle is set too high, the computer will cut fuel to the injectors to bring things back to normal. Make sure you are setting the idle correctly. You should start your car and let it warm up. Shut it off, unplug the ECU and the EACV valve. Replace the ECU fuse and start the car. Make sure the engine is still hot and then set the idle using the idle screw. With the EACV unplugged, you should be able to get it stable at 750 rpm. Once you've done that, shut the car down, reconnect the EACV and see if the problem is gone.
O2 Sensors: I have heard of O2 sensors causing idle problems, but I think this is fairly unlikely. You would likely see the engine bogging badly and your fuel consumption be terrible if this was the case.
Reset your idle. You may have it adjusted too high causing cutout.
There are a lot of systems that control the idle. It sounds to me like you've taken car of any and all of the obvious ones.
Let's review:
Coolant: Make doubly sure that there is no air in your coolant lines. Best way to be sure of this is to bleed the coolant when the front of the car is elevated slightly. If there is any air in the system, there's a chance it could mess with the IACV system.
IACV: You have a new IACV, so you shouldn't have this problem, but make sure that plunger is in place.
Vacuum Lines: Check for leaks. Using soapy water in a spray bottle works well for this. Spray the hose, and if you see bubbles, forming up in a place, you have a leak. Be thorough as vacuum line leaks are hard to find.
Idle: I'm starting to think this may be part of your problem. If you idle is set too high, the computer will cut fuel to the injectors to bring things back to normal. Make sure you are setting the idle correctly. You should start your car and let it warm up. Shut it off, unplug the ECU and the EACV valve. Replace the ECU fuse and start the car. Make sure the engine is still hot and then set the idle using the idle screw. With the EACV unplugged, you should be able to get it stable at 750 rpm. Once you've done that, shut the car down, reconnect the EACV and see if the problem is gone.
O2 Sensors: I have heard of O2 sensors causing idle problems, but I think this is fairly unlikely. You would likely see the engine bogging badly and your fuel consumption be terrible if this was the case.
Reset your idle. You may have it adjusted too high causing cutout.
