Ok heres the deal, I have a 95 gsr first of all, the car runs and idles fine while the engine is cold and has not been run for a while. But then when the engine gets hot after a period of driving (20-30 mins) the car hesitates when i start off in first and second gear and even in fifth gear on the highway. While the car is stopped at a light, the motor sounds like it wants to stall and the rpms drop way lower than where they should be. It sounds like the motor is misfiring at idle actually. Well i already had the plugs, cap, rotor, and coil replaced along with an oil change. My mechanic swaped out the wires from a 98 prelude that was there with my car and it made no difference. What else could be making this happen??? Keep in mind that it only occurs when the car is hot. I am really stressing out about this, so any help is GREATLY appreciated. Thanks.

 

I had the same problem with my 95 LS. It turned out to be a loose wire on the O2 sensor connector (male side) to the wire harness. Are you running rich? Does it go away after certain RPMs? I would have to rev over 4K and stay up there to kept it from hesitating. You could also check your timing...

 

yea, it goes away after about 3500 rpm's...how could you tell if your running rich or not?
Would i check the cam timing or the ignition timing?

 

I had this problem on my LSV OBD2, and it ended up being a lose and dirty sensors on my Throttle body, from when I had installed my new TB, a month prior. But it could also be timing. Are you running a AVFC?

 

no, not running an AVFC....i just have a CAI and header.

 

I would take your car to a shop and get it checked. Have you driven your car threw big puddles or in the rain with your CAI on...

 

my car just came back from the shop after changing all those parts. He couldn't figure it out. I did drive through the rain with the cai on last week, the misfiring started happening the day after it rained. But i dont think that would be the problem because the car did not stall out in the rain or bog down. It wasnt until the day after when the ground was dry when i started having problems with the car.

 

Try messing with your idle control screw located on the throttle body. You will need the car to be running with your radio shut off, all the air and what not shut off, head lights shut off. Adjust the idle before your fan kicks in on radiator. Needs to be around 850rpm +/- 50.

 

well for me, my rear bumper was caked with carbon and my gas mileage went down hill. I burned up a half a tank by only traveling 90 miles. You could also check your plugs and look at the color. If I remember correctly if they are white color then you are lean and black is running rich. (HT correct me if I'm wrong with the plugs to see if your running lean/rich.) I checked both cam timing and Igntion timing. I also check my TSP, O2 sensor on the IM and MAP sensor until I jacked the car up and check the O2 sensor on the header. I hope this helps.

 

ok, i'll check my o2 sensor today...bump

 

plug looks ok....so i dont think it is the o2...is there anyway to test it? Im positive now that the idle is screwy only when the car is hot...in the morning it is ok...i dont get it??

 

bump..it was hot today...no good performance.

 

it sounds like a bad coil. can you get another new one to try?

 

well im already on the second new one...

 

bump for other ideas while waiting in the rain

 

I had the exact same problem on my LS and it turned out to be that my headgasket was bad. First I thought my cat convertor was clogged, then I changed my tps sensor, then my 02 sensor then I bought a brand new distributor and I had the same problem. I would drive for like 30 minutes and then the car would start to misfire and then eventually it would misfire so bad that I couldn't even drive. I also put a different set of injectors in.

 

i dont think it is the headgasket because my mechanic changed the plugs and didnt see anything wrong with them. Now im thinking timing?? Would the car only idle funny when it was hot because of the fast air idle switch (i think thats what is caled) is compensating for the cold startup with a higher idle? I unplugged the tps today and that did not change a thing so it is not that and i checked the plug on the o2 sensor and it seems fine.

 

Have you checked the IAT sensor?

 

hey everyone I'm having the same issue but it happens as soon as the car warms up seems to happen more when the car is under load. I tried taking the cat off cause I thought it was a clogged cat but that didn't help, then I changed the distrubutor and still the same problem. The car is also idling around 3000rpm. I cleaned up the rotor and cap and made sure all the connections were good, as well I changed the spark plugs(the old ones looked fine). It does eem like the car is running rich. Can anyone help me with this???

 

what is this iat sensor?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cosmokramer &raquo;</TD></TR><TR><TD CLASS="quote">what is this iat sensor?</TD></TR></TABLE>

Intake air temperature. It is part #18 in the diagram.


This is getting towards the fringes, but the IAT tells the ECU how hot the intake air charge is. You may want to google "hondahookup manuals". You will find a good download there to aid your trouble shooting.

 

well i had the timing checked out today, everything lined up with TDC. I guess im gonna have to take it to the dealer so they can test all the sensors and ****....dammit. Are there any other alternatives to this?

 

ok so I was having the same problem and had checked everything possible the last thing I checked actually turned out to be the problem. Check the timing on you cam gears my cam is screwed and it caused this problem, because when your engine is cold the cam timing is different then it is when it gets warm which is why you would see the difference is performance. Make sure you check the cam timing when the engine is cold and then warm hopefully you'll see that you're timing is off. good luck let me know how it goes

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by loughnan &raquo;</TD></TR><TR><TD CLASS="quote">ok so I was having the same problem and had checked everything possible the last thing I checked actually turned out to be the problem. Check the timing on you cam gears my cam is screwed and it caused this problem, because when your engine is cold the cam timing is different then it is when it gets warm which is why you would see the difference is performance. Make sure you check the cam timing when the engine is cold and then warm hopefully you'll see that you're timing is off. good luck let me know how it goes</TD></TR></TABLE>

Engine temperature does not significantly affect cam timing on a B18C1.

 

i would check your fuel pressure at the fuel filter when the car is hot then check your fpr.

On personal note. i had a similar problem with my GSR it would bounce the idle when it was hot and i bog out . i changed the 02 sensor b4 the cat and the tps sensor and that seemed to work for me. but you already tried that so check fuel pressure. hope that helped.