My car is currently at my mechanics (he works mostly on domestics) and he is telling me that the car is hesitating around 2000 to 2500 rpm at part throttle, but only when the engine is up to temp, when it is cold, it runs fine, also after the engine is warmed up my air fuel ratio gague reads rich most of the time. I'm thinking it is a bad o2 sensor, what do you guys think? the cap and rotor have alreaty been checked and there is fuel getting at least up to the injectors and the pressure is good. I am trying to help him get this solved so the car can pass emisions testing and i can finally drive the car after long months of being without her, thanks

summary, could it be a bad 02 sensor or what else?

 

up, for the morning crew

 

I had the exact same problem and still do everyonce in a while. I do have a turbo and I have always thought it was the boost the was causing the problems. I can tell you ecactly what it is. IACV!!! I had spent over $400 trying to figure out the freakin problem. I went to 3 diffeerent mechanics and all of them were blamming each other(they had no idea). So after replaceing most of the ignition componets, got a new fuel pump(walbro255), replaced TPS, VSS, and then finally The Idle air control valve. That was the winner! But be warned! They suck *****! I have gone through 3 of them and ever time they fix the problem for a month then the gremlins come back every so often. All I have to do restart the car at a light. If this is not your problem MAKE SURE YOU HAVE A HONDA cap and rotor. I got my first and last one at autozone. After I put on that crap from AZ my car was screwed. It started happinging the same time as the IACV so it was very hard to distingwish between the two problems. The Cap and rotor from HONDA is a bit more expensive then AZ like 25 for both. I can tell you you will save alot of time and money if you just buy handa parts. Unless you want a lifetime warrenty and you are mechaniclly inclined get axels and crap like that from auto zone. 60 for an axle and lifetime warrenty can't be beat(unless you are seriously boosted!)Good luck

 

I had similar symptoms. In my case it was the O2 sensor. You might try holding a steady rpm in neutral of 2200 or so and see if the rpms vary by 75 or so. Mine did.
Another test would be to unplug the O2 sensor and see if it goes away. This will of course evntually set a CEL. Mine didn't for at least 15 minutes.

 

well now that codes were finally read, i believe he got a code 6 for the coolent temp sensor, and that is the only code that is comming up, he is going to install a new one and see what happens, thanks for the ideas guys


[Modified by bikeboy80, 1:47 PM 9/25/2002]

 

well i guess the coolent sensor wasn't it. its still giving us problems, he drove it for an hour and it was fine, but as soon as he put it on the dyno to do the emisions testing the problem came up again. there are no more codes being thrown. as far as i know he has checked everything, wires, sensors, vacume lines and nothing, we are both at a loss of what it could be, the only thing right now that he is looking in to, is even after all that driving the rad fan has still not come on, could that be the problem? also the fuel seems to be ok, my fuel press gage is reading normal, and ther are no weird movements untill well into the problem (btw the sensor is taped into the fuel rail)

some background info this engine was built and reinstalled into my teg, and ran perfect, i totaled the car 2 weeks later, and the engine has sat for about 8 months, i then reinstalled in in a civc with the wireharness from the teg, and now we heve these problems.

HELP!!!

 

one more time, for the morning guys, this is driving me nuts

 

Try unplugging the vacuum line from the EGR valve (If it has one.) and see if it stops doing it.

 

thanks, i think we figured it out, finally got a new o2 sensor in there and so far it is running good, we'll see tomorow when i got for emisions testing

 

if that doesn't work, replace your plug wires... i had a similar problem and went through o2 sensor, MAP Sensor, 4 sets of plugs, vaccuum lines, compression tests, distributor, ECU, and even other stuff...

 

well the engine ran great all weekend and up untill this morning, it started again about 30mins into my drive and lasted for the last hour of my trip. when it happens my air/fuel gague is pegged at rich and doesn't move, im thinking it might be the tps now, don't really know what else to try, any other ideas?

 

This may not be the problem, but your situation sounds similar to my experience...

I first tried a generic Bosch O2 sensor on my Si for about $60. It worked for about 2 weeks. I exchanged it for another that wouldn't work at all. I got my money back and bought an OEM from hparts for about $106. It's been working fine ever since.

 

i really wanna know what the prob is..keep us updated

 

yea i think the mechanic might have put a genaric in, i remember it being cheeper than i thought they normally were. i'm going to run it up to him tonight and make sure the sensor isn't fried, im really woried that something in the ecu either broke or fried in the accident, unfortunatly i dont know anyone in the area with a ls ecu i could borrow to try

 

o2 sensor went bad(and yes it was a genaric $84), im going to put another one in, to see if perhaps the other one was a defect (i really dont want to start putting in honda sensors and have it not be the sensor and start waisting alot of money, but i guess any way you look at it this is not going to be cheep), if it goes out then there is definatly a problem with something shorting it out, my only thought then is to see if i can find another ecu to try to make sure mine is good or not, if it still happens with a differnt ecu, then i guess i drop the cash for a genuine honda sensor to try

 

perfectionist- do you remember what the part number of the o2 sensor was? thanks

 

I bit off topic but just wanted to say fun thread to read, good info. Hope U get it working