'97 Civic D16Y7 Auto

Once engine is fully warm, idle speed is good (700-800RPM) immediately after starting only. Any touch of the throttle, shift out of park, etc. causes idle speed to drop (400-600RPM). On cold start idle is around 1500RPM.. normal, then will drop to 700-800RPM upon warmup.

At times when shifting from R to D, the idle will drop so low the transmission has trouble completing the shift! I would say this is at about 200-300RPM.

I suspect a problem with the TPS, though no code has been set. Nothing surprises me with this ECU after I've had two "unreported" part failures (1st O2 & Shift Solenoids).

Anyone have an idea?

thx

 

first thing would do is cleaning out the throttle body --with the car off have somebody hold gas pedal to the floor --spray some carb. cleaner down it [a little at a time u dont want to flood it ][:@] then start it & blow it out --repeat a few times --it cant hurt

 

yo m8, ive had the same thing only on a manual d16y7 uk car. what i did was on the right hand side of the airbox there is a screw if you adjust this once u think the choke has come off, it should be fine. dont lean on the cable as it will rev the engine. i think as the thred comes toward you you make the idle higher and as it goes in its lower. anyway u will fiqure it out.

hope this helps, it sorted mine from stalling at idle.

Richard

oh and if you have a 02 code 1 ecu fault so do i. its the sensor before the cat looks like a spark plug. im in the process of sorting a 4-1 mainfold so i will "decat" it.

 

My throttle body is quite clean, I tend to keep on top of these things.

Secondarily, adjusting the throttle manually does not explain why this is happening. This may be a "quick fix", which I might consider if the engine was stalling out, but it is not.

RPM is good in certain stages, so adjusting the throttle manually will only cause it to rev higher in all ranges.

One thing I'm going to take a look at is the thermo-switch, and try adjusting the IAC valve if I can..

PS I have adjusted the throttle in the past. On most fuel-injected engines (proivided everything is kept clean) there should be little or no need for manual throttle adjustment. And the car does not have a choke. You must be thinking back to the carbureted days of old.

What I'm looking for is someone who knows these _electronics_, thank you anyway.

 

Djglovehead, the sensor you're talking about is the Primary O2 Sensor. This one can cause some awful engine performance if it's bad.. You might wanna try changing that out to see if that corrects any of your problems.

One of the "unreported" failures I mentioned was that O2 sensor.. the engine would bog out periodically, and no code was ever set. Then the vehicle failed an emissions test miserably. I checked the sensor following the instructions in my Haynes manual (which is a must-have) and found it not reading right. Replaced and voila, passed the test with flying colours and no more bogging.

And where the heck do you live if you're allowed to "de-cat" it? In any case, even if you remove your cat you will still need that sensor.. it monitors the content of the exhaust gases and helps the ECU determine the correct A/F mixture. The secondary O2 sensor (under the cat) monitors catalyst performance.. if your remove your cat you can expect a code from that one for sure.

 

try to get a scan tool &hook it up to your obd2 connector &watch the o2 sensor ,also make sure it goes into "closed loop"

 

You can monitor O2 performance with a multimeter as well.

The O2 is working fine.

Next.