jim beam <nospam@example.net> wrote in
news:UsGdnczhoJVjpzbZnZ2dnUVZ_oGdnZ2d@speakeasy.ne t:

> "TeGGeRï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï ¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï
> ¿½" wrote:
>> amb@bronze.lcs.mit.edu (andrew m. boardman) wrote in
>> news:e8bhrc$13nt$1@grapevine.csail.mit.edu:
>>
>>
>>>The short version: What, on an '89 DPFI 1.5l engine, does the ECU use
>>>to determine target EACV opening and idle speed? What would cause
>>>the ECU to suddenly decide to command a full-open EACV without also
>>>indicating an error?
>>>
>>
>>
>>
>> You have a giant air leak.
>>
>> I don't know if you have a Fast Idle Valve, but on multi-port cars
>> this is the prime culprit.
>>
> yes, but the ecu's commanding the eacv to do stuff. it's got to be
> one of the input sensors...
>


It's a big air leak. That means one of the secondary air inputs into the
intake is bad. Or there is an input that is not supposed to be there
(something split, etc). The ECU is feeding gas to keep the mixture correct,
then cutting fuel when the RPM limit is reached, then repeating itself...

Another diag tool I forgot to mention: Partially cover the throttle body
with your hand. Cover more and more until the idle settles down. If this
works, something is admitting way too much air.

With any port-injected car, the thing to do is to cover the lower port when
the car is warm and idle is fluctuating. If vacum is present at that lower
port and idle settles down when you cover up the port, then that's the
problem.

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TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/