happyabortion

oki so i have a 98 civic d16y7 automatic. its been running fine and all of a sudden this morning when it was really cold i tried to start it and it wouldn't turn on. after cranking on it over and over it finally turned on and idled low. when i tried to press the gas it would choke and die. after messing with it i left it idling low and while it was running i unplugged the map sensor. it stuttered a little and idled up. once it did that i plugged the map back in and it reved up perfect. and drove fine. continued to drive fine. so i let it sit for a few hours and when i started it again the same thing happened.

so i replaced the map sensor i let it sit some more and still same problem. im stumped. i've never had a problem like this. maybe someone can help me out. i dunno what to do. im throwing a cel for 02 sensor but i've been throwing it for and it ran fine. any ideas?? any help is GREATLY APPRECIATED!!!!!!!!!!!!!!!!!!!!!!!

civicgsr499

did u check the IACV

happyabortion

how would i go about checking it? i dont have a spare one....

civicgsr499

well i know u can use a screwdriver to adjust ur idle

happyabortion

sorry man but this is not a problem with the idle adjustment its some sensor tripping everything out i just dunno what

civicgsr499

well do u need a new map sensor?

gsrhatch2356

if you know you had a problem with the o2 I would stand ground on getting that fixed cause it could have finally just died and could be doing god knows what to the fuel adj made by the computer to compensate for the 02 signal.

civicgsr499

nvm ijust re-ead it and u replaced it... too bad. i had an extra one lying around

happyabortion

true it might be that but then it wouldn't just start working after i unplug and plg the map dont you think? well ill be changing it tomorrow hopefully that fixes it

gsrhatch2356

when you unplug the map sensor it dosent have any data as far as air and so it defults to a predetermined fuel map and that could be the reason why it seems to run fine when unplugged but then once turned off it sees the map signal again and try to fall back into fuel adj based off of sensor signals like 02, map, tps.

happyabortion

ah! well i got an extra o2 at a friends house ill go get it after he gets off of work and ill let you guys know what happens. thank alot guys!

happyabortion

oki so i've replaced the O2 sensor and now its throwing a code 3 , 7 ,and still throwin 41. i know the o2sensor is good and i already replaced map sensor i dont think i need to replace tps too it has to be something tripping everything else out. i just dunno what. anyone have any ideas? im gonna reset the ecu right now and hopefully it fixes it.

brent_si

The iacv is located on the back of the intake manafold. Their should be 2 bolts holding it in place. If you take it off you will see a little screen that works like a filter. It may be clogged up if so take some brake parts cleaner and spray it all out. Then just wait for it to dry and reinstall it.

Now the not starting correctly could be a few things but I would check your fuel pump and starter. Next time crank it once if it doesn't start then go tap on your gas tank with something. If it then starts up its prolly your fuel pump.

94EG8

The OP has a D16Y7. It uses a throttlebody mounted IACV, completely different design from the more traditional IM mounted IACV IIRC.

gsrhatch2356

I dont know but anytime I see a map sensor and a tps code it usally is that the connectors were switched around but if thats not the case then you are going to want to check the three wires coming off of it 1 wire which I am pretty sure is green with a black stripe is the ground wire and both sensors share it but if you take the black lead of your multimeter and put it on the negitive of the battery and the red lead on the ground of the sensors you shouldnt see any voltage but if you see .5v or more there is resistance in the ground if you see 5v then there is no ground supplied by the computer. 2 another wire is going to carry the 5v supply and it is pretty self explanitory if it dont have 5v there is a problem (4.99 or 4.98v is cool) then with the tps sensor you should be able to get on the signal wire and as you slowly open the throttle you should see a smooth tranistion of voltage. if it jumps real quick or drops off completly then it is going to need a new tps sensor and with the map sensor you are going to need a vacuum gauge but you can use this chart to compare your readings to your mechanical gauge.

gsrhatch2356

and as far as the code 41 all I can say is take the 02 out and hook up the two black wires off of it to a battery and see if it gets hot like a ciggerete lighter

happyabortion

thanks everyne for their input! after i reset the ecu earlier the car ran smooth! it was late when i swapped out the o2 sensor and i got lazy but this morning when i walked out there i unpluged my batt. for a little bit and once i hooked it back up idle was perfect with no check engine or anything. O2 sensor was definately the problem.


thanks everyone i really appreciate it.

gsrhatch2356

Well sweet but just make sure after a few days of driving that everything is still up to par. I will still check back to see if any of your codes come back