can a dirty IACV cause car to run rich?

I am just curious because my car seems to run rich and i have changed o2 (which it throws a code for sometimes) and checked almost anything else i can think of. Also when i am on the throttle and then let off completely my rpm's fall to like 300 and then pick themselves back up to 750 or so. Is the IACV causing this?

 

sure could...low coolant could also. whats your readings at the o2?

 

well if you mean voltage i am going to check that tonight when my brother gets home from UTI

 

make sure you use a graphing meter should always fluctuate exept during initial couple secs..

 

well since i found out that my brother wont be home until tomorrow and he has the voltage meter i went out and changed my iacv with another one i had lying around that was much cleaner. The car seems to be running better now like when i let off of the gas the rpm's dont drop so low but the damn o2 code still pops up

 

o2 is probably not bad but is TELLING you with the Engine light that you are running rich...check your coolant temp sensor

 

is that the one on the side of the head?
and if so is it the one with one wire or is it the one with the plug/clip on it?

 

more than one wire, i have to double check, give me year/make/model and engine code

 

it is an 88 crx dx with a sohc zc obd0 running a pm6 and the stock dx tranny and i know there are two sensors on the side of the head by the distributor, one is a one wire sensor and the other is more than one wire (i think it is two).

But do you think this could be the problem because when i bought the car it had the stock d15b2 with the dpfi and it threw the o2 code, then i changed over to mpfi on the d15b2 and it still threw the code (whole new wiring harness), then i did the motor swap to the sohc zc and it still throws the code plus i have changed the o2 to the one that came with the sohc zc.

Let me tell you i am almost completely stumped on what could be causing my code. I have checked the fuel supply system, the cat, changed the map sensor, and when i did the swap you know it came with every sensor the damn car has except for the map and baro sensors so i am running out of ideas as to what is making my car run rich.

 

obd0 u said? ok, you have to check the o2 than and the wire. follow it back to pcm and check for continuity

 

by pcm do you mean the ecu?
and if that is true i will give that a shot tomorrow
also do you know what pin it would be in the ecu?
thanks for all the help

 

yea ecu...w/e. or just do it at the harness going to ecu which is alot easier. so connector at o2 sensor to pin at harness at ecu. single wire o2 right?

 

yeah it is a single wire. But i will give that a try and post the numbers i get maybe tomorrow or wednesday. but for now i have to go to school tomorrow so i am going to log off

 

alright keep me posted

 

well i went over to my friends house today and used the multimeter to check the voltage that the o2 is sending to the ecu. It shows up as 0 all the time and the car is at operating temp and i used the manual to do the "proper" procedure to check the o2 and i am now guessing (if we checked the voltage right) that the sensor is just bad.

What o2 do you recommend because i heard that bosch are no good?

 

bosch are junk. sometimes bosch use the ntk body. but stick with ntk or oem. sounds like a bad o2 tho with 0 volts going out...you had the car running correct?

 

yeah the car was running correctly but my auto teacher at school also brought up the point that the o2 might just be so clogged with carbon buildup that it cant read so i guess i will hope under there today and check it out.

 

well checked the o2 sensor and it is very black but the fins or vents or whatever you call them are still open but it is soo black that i might as well just buy a new one and go from there.

 

yeap do that first

 

well i have no income at the moment so when i get some cash i will and i will keep it posted