dacatzmeow57

This is my problem and hopefully someone can help me...

Ok, I have a 2000 honda civic and it ordinarily runs well, but recently I have been having a problem with it "bucking." This is what happens: when I am accelerating (not ALL THE TIME, but a lot lately) I reach a certain threshold with the gas pedal and it starts kicking pretty heavily, like it wants to either accelerate or decelerate, but when I hold the pedal at these points (~35mph) it kicks back and forth. Also, when I am on the interstate or just driving at a constant pace and I barely let off the gas, it decelerates quickly and makes a small jolt once, like I am not even pressing the pedal. It is a hard condition to describe with words, but I am sure you catch the drift.

I have tried cleaning the throttle body with a cleaner, and it temporarily alleviates the symptoms, but doesnt fix the problem long-term. Does anyone have any suggestions?

Anthony R

b16em1

try repalcing the plugs and dizzy cap and rotor

angel_i

Is your check engine light on? Your motor mounts might be shot if the light is off.

Civic_07

I say check your engine mounts(Y)

dacatzmeow57

actually, the check engine light has been on for a while (just before I hit 100k miles) and I figured that was the engine realizing i was at that mile marker, so it came on. the car was fine at that time. here we are, ~25k miles later and I am having these issues. I will check the engine mount. are there any other suggestions? like I said, i've sprayed the throttle body and it alleviates the symptoms. is that indicative of something other than a mount?

obuhmyuh

i had that happen to me. check your code, mine turned out to be a bad tps.

jdm91CrxSi

ignitor(replace your distributor).. im going through this same problem.. your rps should be jumping too..

if not probably your tps

itsmejto

yup, check the codes, and repair whatever is setting them, probably a blocked fuel filter, or ignition/plugs.distributor/ignitor coil, problem or the tps, all will set codes if faulty.

dacatzmeow57

I went to auto zone to see what the computer will say about my check engine light and I had 2 codes: 135 and 505. The O2 sensor and IAC valve. It didnt say anything about the TPS, plugs, ignition coil or anything like that. Any clues?

DTA-Zombie

IACV - idle air control valve - back of intake manifold clean it -

replace O2 sensor - get choice from auto zone, oreilly, advance, ebay - no seriously ebay is cheap and reliable - I got mine w/ connector and all for ~40 bucks brand new w/ warranty

dacatzmeow57

I clean my intake frequently, which alleviates the symptoms but only short-term. I will wind up replacing my O2 sensor, but I am wondering if I should do something with the TPS also, even though the computer didnt tell me to...

Pothole987

no point, the computer says its fine, its fine. spray some brake cleaner in the throttle body holes to clean your IVAC, or replace the IVAC

angel_i

Clean the IACV.

sirEGhatch

did u get it fixed? if u did what was the problem?

dacatzmeow57

Ok, I STILL have not gotten it taken care of, lol. It runs fine, except for every once in a while when it does it. Hopefully this video can help paint a picture. If you listen closely, you can hear it jolting.

Here is the link: http://img531.imageshack.us/img531/2403/1000478gz2.flv

hockeybeerbong

I'm having this same problem. I get to 4000rpm and it is like hitting red line. My friend had the same thing happen to his nissan sentra, which was the fuel pump. But this was not the case with my civic si 02. I replaced the fuel pump and nothing different. So I'm open to options

92ehatch

does your car have an EGR valve?

blocked EGR ports can cause that symptom.

although i dont think it has one.

the TPS could be the problem.

could be a misfire, bad plug, ignitor, fuel injector, wire.

grumblemarc

iTrader: (4)

Did you say 02 Civic and not 92 Civic?

hockeybeerbong

After reading the codes, it was a vtec malfunction code. so i cleaned out the vtec solenoid and topped up the oil. all better now

delsolintegra

That's good. I was going to suggest maybe a bad ignition wire.

Ryan H. Bream

So I see a lot of you put down iacv is the issue every time p0505. Not always the case. I have a 00 si with a b16a swapped in. I had the fluctuating idle and now the bucking. Took care of a vacuum leak at one of the fuel injectors. Replaced the iacv with a know good one. Checked timing. Cleaned throttle body. Wires are all connected correctly. Did the idle relearn and cleared codes. I can unplug the IDC and the idle will drop the whole way down. At cold the rpms after a relearn will be a little over 800. Not too bad but as it gets warm the idle slowly climbs to 1200 rpm. Then eventually sets p0505 and starts acting up causing the bucking situation. Coolant is fine and temp. Map is reading 7hg when running. Which is weird cause it should be around 22hg like the rest of the intake. Not sure if that is spec or not. No codes for it. See if someone can answer this one for me. Be worth it