Vtec Civic 93

Alright I've got a 1999 honda civic dx, its got a b18b swap from a 98 integra in it. It has the stock dx harness in it but is converted to obd1 via jumper harness and is running a p75 ecu, the car has the cyp hack or whatever its called where u bypass the sensor on the oil pump. I'm having some weird idle issues with the car and 2 engine codes, 20 and 41.

It started with the car idling bad, to the point where it would stall sometimes but no check engine lights. Then randomly the car threw 2 check engine codes, a code 20 and a code 41 and my speedometer stopped working. Not to long after them codes are thrown the car starts losing power then eventually dies. It won't start u can just hear clicking like the batteries dead. I then jump the car and it starts and runs. I take off the battery positive and the car dies. I then assume its the alternator and get it tested at autozone, it passes all there tests so I check the battery and its faulty. I bought a new battery and it starts up and stuff fine but still idles bad and drives like ****, real boggy anywhere below like 3200rpm and seems super slow when on the gas. I cannot figure out what the hell is going on and the speedo still doesn't work.

Any help is appreciated!!!

Vtec Civic 93

Bump

thyzie

there a flat head screw but the TB try tightin it while the car is on maybe that will help

TurboTron

try the Idle screw on the throttle body. make sure all vacuum lines are hooked up on the intake etc. I just looked up the codes you are getting... #41: oxygen sensor heater. This will not make your car do what it's doing. #20 is your ELD, Electronic Load detector. So, somewhere you are getting way to high of voltage. I'm going to keep researching this a bit........

Vtec Civic 93

Thanks guys, and id appreciate that turbo tron, the car died again last night due to the battery draining so I'm thinking my alternator is bad even though autozone said it was good, a code 20 can be caused by a bad alternator too so I'm gonna replace that when I can and see.

Also I think the idle could be due to timing, when your "on" the car you can hear the intake cam be open a lot longer then it should and that would make the car feel really slow too I think.

Vtec Civic 93

Put in anew alternator and the car is doing the exact same thing, still idling horribly. I pulled the positive battery cable off to see if the car would run off the alternator and it did, barely. The car ran at like 200rpm and ran like absolute ****. So my alternator isnt getting enough power im assuming, which could be because the Electric Load Detecor is bad?? (code 20)

Help!

Vtec Civic 93

Well after a 5 minute search on club civic, it looks like all 3 of my issues are due to fuse #15 in my under-dash fuse box. Controls the ELD, VSS and 02 sensor which is all 3 of my problems lol. Caused by wires rubbing and shorting on the engine harness below the intake manifold.

Club civic ftw!!

Still dont understand my idle issue though...

raidacaipo

Yes I was going to suggest replacing your fuse #15 under the drivers dash. It was probably blown. Second thing is to make sure all your grounds are good otherwise that alternator fuse will pop again. Many people who perform a swap tend to forget to tighten all the ground wires or even forget to add ground wires. I was one of them. So double check.

3 major grounds to check:
1. Head to chasis
2. Transmission to chasis
3. Thermostat ground

Then replace your primary o2 sensor with a good one. This should solve your problem and the engine running like ****. However, if the secondary o2 sensor goes bad, it will not affect your engines performance as much as the primary.

Vtec Civic 93

I looked over grounds and there is no ground going to the thermostat, i couldn't find any ground dangling in the engine bay either. Also, i'm only running 1 02 sensor, the secondary 02 sensor plug is just chilling in my engine bay, because i'm converted to obd1.

Can i re-run the thermostat ground? Connect it to the thermostat then to where?

raidacaipo

Then you need to replace that primary o2 sensor. The one on the downpipe of the header not the one on the cat. The thermostat ground is a small ground that is connected with your engine wire harness. Unlike the other grounds which are separate from the engine harness and have bigger wires, the thermostat ground is connected with the wire harness like the starter or alternator ground is. Look for that and you should see a little bolt or a spot where you can bolt it into the thermostat. So check your wire harness around the thermostat sensors.

Also check the alternator ground. Wiggle it just in case it didn't break or anything like that. I remember mines broke because I kept twisting it but you couldn't see that its torn up. So yeah wiggle that alternator ground and make sure its firm along with tightening the bolt for that.

Vtec Civic 93

Well the codes are gone, was just that little fuse.

We re-did the timing, it was off alot. The car runs alot better then before but still has an idle issue. The car will be idling fine, at like 700-1000rpm then out of know where it will cut and drop to like 400rpm, then pick back up to normal idle. You can also still feel it want to be alittle boggy and choppy during normal driving, but sometimes it will drive perfect. Replacing the fuel filter tomorrow, see what happens.

Any suggestions?

thangnhocngheo

im doin a swap on my car rite now.. im having the same problem.. wat i find out is it might be ur map sensor is connected to pti... something like that.. but double check ur map sensor.. imma check out mine 2morrow... hopefully its the issue... let me kno if it is..

raidacaipo

Its probably a IACV problem. Take if off the manifold, get some carb cleaner and spray into it. Then shake it for a bit and let it dry over night or simply shake it hard so that all the carb spray comes out. It will simply burn off when you drive. This may fix the problem. Also try and adjust your tps. Your going to need a multi meter to do this. Check this out on how to adjust the TPS:

http://www.youtube.com/watch?v=ukPoe5E4Fqg

Vtec Civic 93

Thanks man I appreciate it, my iacv for some reason is directly wired to the ecu plug. There's 1 big wire ran from the iacv right to the the plug on the harness, its not ran through the harness like normal, idk why. It will still be boggy and choppy while driving too, some points it drives fine other times u can tell something is holding it back, maybe fuel or something. Ill def check the tps too.

Also, which engine harness can I use to replace mine? Like 99-00 civic dx, lx, hx, ex, si??

raidacaipo

Any 99-00 Civic Ex or Si harness will plug and play without any wiring. I don't think its necessary to replace the engine harness yet. I think you should try and clean the IACV first which is the easiest thing to do.

Probably someone modified your stock 99-00 Civic Dx harness and added the necessary wires to make a B swap work which is what it sounds like. So they added those IACV wires but did a bad job by not tucking it into the engine harness.

Vtec Civic 93

Will other 99-00 harnesss work? I was told an ex/si harness won't work. Idk but yeah ill clean the iacv.

raidacaipo

Why do I always have to repeat myself? Go and believe in whoever told you that then....

Vtec Civic 93

I'm not saying I don't believe you I'm just saying I thought I recall seeing numerous people saying you can't use a ex/si harness in a non vtec car/engine. I know the dizzy plug is bigger on vtec harness's, would I just cut that plug off and wire in my plug?

This is a last resort as well, I'm gonna try cleaning the iacv and doing the tps adjust.

Vtec Civic 93

Sorry for doubting you, i just know the the 99-00 si/ex harness has a bigger dizzy plug, do i just de-pin that plug and use my existing obd2 dizzy plug that fits my dizzy?

raidacaipo

It depends. If you get a 99-00 Civic Ex/Si Wire harness, then the only thing you need to modify is the distributor wiring for the obd1 distributor. Since you have a b18b non vtec motor, you will have a couple of plugs that will not be plugged in but don't be alarmed. However, the 99-00 Ex/Si harness has the IACV conversion done to it already so you wouldn't need to modify that like on your original harness.

99-00 Civic dx, cx, hx engine harnesses are made for non vtec single cam motors. That means you will still need to modify the IACV plug and other plugs because the plugs are made for single cam NON vtec motors. You will still need to modify the distributor wiring to convert it to obd1.



This diagram is wrong however, it may help you out a bit.

If your on a budget, then you can find a 99-00 Civic Dx, Cx harness however, you will need to modify a couple of the plugs. But since you have a non vtec DOHC motor, this means you will only have to modify the IACV plug, the maps sensor plugs and and probably the IAT plugs as well.

However, if you have the money, then get a 99-00 Civic Si/ex harness because no modification is required besides modifying the distributor plug to obd1 because you have a obd1 distributor. Also you will have the vtec wires and knock sensors already on there for future upgrades if you plan on getting a vtec motor.

My advice:
Keep your stock civic harness. You can try and double check the work thats been done to it. The person who modified the harness must have only modified the IACV, IAT, and a couple of other plugs. Check out this diagram to figure it out.

http://www.phearable.net/tech/wiring/wiring.99-01_2.jpg

Check for any loose wiring on the ecu. You would usually have to repin each wire when you do the IACV conversion. Sometimes people just stick wires into the ecu plug and sometimes they do it correctly by repinning it.

raidacaipo

^^ before you go and do all of this that I described above, did you try cleaning your IACV? it seems like thats the problem and not your wiring. That is my best bet so far. Either try cleaning the IACV with some carb cleaner like I suggested or try replacing it with your friends. That is probably causing the bogging. Also cleaning your throttle body wont hurt either.

If this fails, then it could be the ecu. Try another ecu. If that fails then its probably wiring

raidacaipo

Also nobody mentioned this yet but I would highly recommend checking the spark plugs, distributor cap and rotor, distributor wires and ignition timing. Change them if necessary. This could lead to your bogging problem.