i just recently bought a 91 CRX si, on the way home i noticed it starts to buck in high rpm. it was an hour and 20 min. drive and it didnt break down.okay i go to start it and it cranks fine and everything but doesnt run unless i give it alittle gas to get it going, and it idles around 1k ,then i drive it for about 5-10 minutes and the check engine light comes on, and it starts bucking in high rpm. so i pull over and it idles real low and ruff like under 500, shut it off and start it again and the lights off and it runs fine till it happens again, i replaced distributor cap, rotor, plugs, plug wires. idk whats going on here?

 

Check the code would be the first thing to do. Until then just keep wasting money and throw parts at it. Eventually you will fix it.

 

def check the code. ther should be a light on the ecu that blinks. coun t the number of blinks and call your local parts store. they will have a book of codes.

 

it doesnt stay on and the way ive seen to do it is turn it off then put the key in the on position. will this work even if it doesnt come on until i drive it?

 

No dont turn it off! You will loose the code, so pull over and check it while you can.

 

i checked it and it blinks once pause once pause doesnt that mean its fine? and im thinking its the throttle position sensor?

 

1 is the O2 sensor

 

so when i look and it keeps just doing one blink then a pause then one blink pause over and over thats o2 sensor? and what would that have to do with the bucking and everything? i read symptoms of a bad throttle position sensor and it sounds exactly like the problems im having

 

fix the CEL first.

 

working on it

 

could be your ecu. mine was like that after i did a ls swap but it was throwing code 17 i think. switched out ecu and i runs fine.

 

its the ecu from a 91 crx dx i believe, and the motor is a d16y7.

 

okay you probably do have the wrong ECU, sorry I'm not too familair with D series.
is your motor wired for OBD0, OBD1, or OBD2?

 

i dont really no, i have no idea what this guy did to the car, he said his friend did all the motor work so he doesnt no

 

Well if you are running a computer for a DPFI and not a DPFI then I can't believe it is even running.

Also if you are throwing an O2 Sensor code, then that could cause your car to do as described symptoms.

 

well it runs so it cant be that? and on this site http://www.geocities.com/chipman_13/ecu.html it says 1 is o2 sensor in exhaust manifold, it has an aftermarket header on it so maybe he didnt put it in, but would that make it buck like it does? and idle low and ruff?

 

dont rule out the ECU, yes your motor will run with the incorrect ECU, but not well.

so have you replaced the 02 sensor yet? can you check out the ECU (there is a bar code on the ECU with a 5 digit number a dash then a 3 digit code, this 3 digit number is your ecu code it will say something like PM9 or PR4, and then theres a dash and 3 more digits.) or post a picture of the code on the ECU?

 

37820-pm6-ao4o
oh and heres a pic of the ecu, is it just me or does this wiring look half assed?
http://i98.photobucket.com/albums/l2...2091502-00.jpg
http://i98.photobucket.com/albums/l2...2091501-01.jpg

 

yeah that wiring looks bad. so you do have the obd0 ecu, which is fine as long as you use the 91 si intake manifold and distributor. or if you want you could spend some cash and convert it to obd1.

in that picture it looks like 2 of the plugs aren't plugged in all the way, whats the deal with that?

Sorry I'm probably confusing you but like i mentioned before fix the CEL before you do any other stuff.

and if you post a picture of your engine bay maybe someone could check to see if you have the correct manifold and distributor.

 

well i no it has the crx distributor cuz when i got a the cap for the distributor i first got one for a 97 civic but it didnt fit i had to get one for a 91 crx, idk about the intake manifold. and idk whats with the wires that arent hooked up i didnt touch the wiring because i dont no what im doing.
http://i98.photobucket.com/albums/l2...7091646-00.jpg

 

okay, but this is real easy, just try pushing the 2 black plugs into the ECU, i can tell they aren't plugged in all the way, btw that picture of your engine bay is real blurry can you get a better one of the intake manifold?

 

i tried pushing them in they moved a little bit, and heres a better pic of the intake
http://i98.photobucket.com/albums/l2...2091649-00.jpg

 

again i'm not that familiar with D-series stuff but that does look like a different manifold i'm not sure which.
Hopefully someone else will recognise that manifold.

So you pushed the plugs in but they dont "clip" into the ECU? they should or they might rattle loose.

 

they seem like they are in there

 

okay thats good.
so considering that your wiring is pretty funky how is the wiring for the o2 sensor? I would check the wiring out. is it even connected? if you have a multimeter you can test the o2 sensor/wiring using a Helm repair manual ( look in the faqs here or try honda tekh.com's faqs)