Im having a weird issue with my b20b swapped ef hatch. When I first start the car its pretty bad, If I give it gas it has a steady miss to it, its not really bad but it's there. Once it warms up it get's a lot better but If im steady driving it and light on the gas is when it starts to miss. If I give the car enough throttle it's fine. It does randomly throw a CEL But as soon as I turn the car off the CEL goes away. Any thoughts? The car was fine for the 1st month it was swapped, this problem just recently started. Im sure the CEL has something to do with it..Thanks..

 

Check the ECU for stored codes since it threw a CEL for you.
Have you set your timing? Ignition system (plugs wires cap rotor) in good shape?

 

To be honest man , I have no idea how to check for a code? The dist came of a older motor, Everything else has about 30,xxx miles on it , including plugs , wires. I was thinking about starting with a new fuel filter and plugs just to see? It wouldnt throw a code because of a fuel filter or plugs would it? I was thinking its a bad dist. but Im not sure...

 

Neither plugs or filter have a sensor on them so they can not throw a direct code.
However, if the filter becomes plugged or the plugs are fouled then other sensors on the engine (like the O2) may pick up on something being wrong and give you an indirect code.

More than likely your swap included a change over to OBD1 electronics. There is a blue plug under the glove box that has 2 wires going to it. Put a paperclip/jumper to short the plug out and turn your ignition to ON. The light on the dash will start blinking. long blinks =10 and short blinks = 1. So long long short would be 21. Codes are separated by long and distinct pauses.

 

Thanks man , Appreciate it

 

I couldnt find a blue plug under the glove box, Car is a 89 si . I used a phearable obd0-obd1 jumper harness...Only plug I saw was the one going to to the blower motor I bealive

 

Hmm...
The connector has one wire that goes to ground and the other wire goes to D4 on the OBD1 connector. So you can find D4 and trace it or just tap into it and ground it.

You can use this for pinout reference.
http://www.ff-squad.com/technet/wiring.obd1.htm

 

My buddy told me that the 90-91 had the plug under the dash, he said the 89's dont. Im a little confused on how to do this...

 

Really? I thought it was just 88 that was odd.
Check over between the shock tower and the radiator reservoir for a 2 prong plug that doesn't go anywhere.
If you still can't find it, the D4to ground will absolutely work.

 

I found the plug under the hood, I grounded it out and turned the ket to ON. I didnt get any CEL Flashes at all....?

 

I also put new plugs in it, The plugs were VERY black , I put the new plugs in and still missing ...

 

Im smelling a lot of what smells like fuel from the exhaust, The inside of the exhaust tip is very dry black soot , it also backfires a lot

 

With all 4 plugs being fouled and backfiring it would hint that you have an excessive fuel issue.
I am guessing that if you grounded D4 on the ECU and pulled the CEL code it would probably show an O2 sensor error.

Some ideas -
Map sensor could be going bad.
O2 sensor could be going bad.
You could have insufficient spark that is sufficient to burn off all the fuel.
Fuel pressure could be too high from either a bad fuel pressure regulator or an improperly set aftermarket fuel pressure altering device (adjustable FPR, fuel pressure iser, etc).
Mechanical Cam/crank timing could be off a tooth.

What ECU are you running?
Is it chipped? Chipped ECUs are meant to be tuned - random 'power' chips tend to set the fuel map way too rich and you run into all sorts of problems.


Really need to pull the codes to figure out why that CEL is coming on.
That's #1 step to any repair.

 

I was thinking 02 sensor, Didnt think about map sensor. I was thinking about a bad dizzy. The car has a base map from a very reputable tuner. Jk tuning. The car ran fine on that ecu for the first few weeks . My car has stock fuel pressure regulator on it. My car does have a walbro 255 pump in it from when it was boosted, but i was told that wouldnt make a difference

 

If I unplug the 02 sensor would that be a way to test to see if it's bad?