.BigSexy

SO I've got a little missfire. Its a stock h22a4 in a 4th gen running on a virgin p28. My guess is it is missfiring due to the unchipped ecu, but what other things would cause this? plugs are brand new but the wires I am not too sure about...brand new distributor, cap, and rotor as well. Any help will be greatly appreciated

nuezdaman44

clogged egr ports, bad piston rings, any number of things... did it start when u swapped ecu's? why do you think its the computer?

.BigSexy

b/c a virigin p28 isn't supposed to be run on an h22. The fuel maps are different than that of a p13. Egr is eliminated anyways....

vinuneuro

You've answered your question..or at least know where to start.

Use ngk wires and plugs.

.BigSexy

Thanks, I was just wondering if that does not solve the problem, where I would begin to look next. I'm hoping that fixes it and yes NGK all the way. I do need new wires I believe....

kornerk12

Im assuming your referring to the ecu. However could the blocked off egr have anything to do with this ? If your not tuned for it wouldn't it cause higher cylinder temps possibly resulting in misfire ? Since the point of egr is to reduce NOx emissions, which only occur with high cylinder temps.

nuezdaman44

yea blocked off egr is even worse than clogged ports.. i just assumed it was still there. i had mine blocked off for a little over a year and when i hooked it back up my misfiring got a lot better, it actually stopped for a month or so.

.BigSexy

Im running a p28 tho, so the egr is pointless....

Pman92

yah p28 doesnt check for the egr Im doing the same thing as u. and yes its the ecu.

mattsnooz

This is likely the main issue unless you alreay suspect something else was wrong before the swap?

Don't run that car too much with the p28 in there. I would love to see your A/Fs using a stock civic ecu on a prelude. That car has to be running like ***. Keep pulling your plugs and see if they are white. Just make sure your not running too lean if your going to keep using that civic ecu without chipping it and getting tuned. I have no idea what fueling conditions you'd be under while using civic maps (for the fact that I've never worked with a virgin civic map)

kornerk12

Well one thing i could see causing problems here is the fact that bseries and dseries do not run egr at all. Maybe for some reason their cylinder temps are not as high and not not create a NOx problem. This is a guess, if anyone has any idea please post.

.BigSexy

the most the car has been running is down the street and back. I drive my daily versus driving the prelude. Anyone know of someone who can chip my ecu for me? I only kow of 1 guy local and our schedules conflict way too much...

boostedmonkey

Why is a blocked off egr worse than clogged ports? If you remove the egr and block it off with a plate, that's what i'm assuming you mean, then you kill gas mileage. The only time an egr will cause a misfire is when the pintle is stuck wide open. Like it's got a piece of carbon stuck in there holding it open. Completely removing it won't cause a misfire. An egr valve is only there for emissions, and therefore hurts horsepower output. That's why a lot of guys remove them. Why do you think that all the JDM motors do not have egr on them? They don't have emissions on their motors like we do. Hence the reason why the jdm counterparts of our motors have a higher hp rating. That and the fact that their lowest octane rating is higher than our highest. I know. I was stationed there for four years in the Navy.

To the OP, i don't understand why you're running a P28 and not the P13 that came with the car. The P28 wasn't designed for that car. If you've got the P13, put that back in and leave it alone.

boostedmonkey

Let me correct a little bit of that. Yes, it will misfire with the egr removed, because the egr should have a connector to plug into it. Without that, the computer has no signal coming from the egr. My 88, it wouldn't matter, because it's not electrical. It's just a tube running from the header, to the egr, which is bolted to the head. So, i can remove mine and gain a little horse power, at the sacrifice of fuel economy, but the newer ones, you have to replace the egr's. Not completely remove them. At least i don't know of a way to do it without causing check engine lights and misfires, unless you just pull the egr solenoid off, keep it plugged to the connector, and use a block off plate. Even then, i'm still not sure if it won't set a check engine light. I suppose you could just loop the connector, but i don't know if that would harm the ecu or not. It could, but then again, it might trick the ecu into thinking that the egr is hooked up, and it will still function as if it has an active egr solenoid. That might be worth a shot. I could find out and get back to you on that.

kornerk12

EGR removal does not net hp gains. It is not there on jdm cars because of emissions regulations only, they do not require them. Removing it will not gain hp, it will only save alittle weight and open up the engine bay alittle more. Of course another reason they are not on jdm cars is the fact that they cost money and why waste money if they are not required.

sohctodohc

what are you guys talking about? the jdm h22a does come with the egr setup...if you dont believe me i will be more then glad to go take a picture of mine.

and just because something is throwing a check engine light doesnt mean its gonna cause a misfire.

when i had my egr completely hooked up and working in my car it caused more issues then it has since ive had it blocked off.

also before saying they have higher octane in japan look how they rate their octane and then compare how we rate our octane, you will see that theirs not as big of a difference as everyone thinks.

nuezdaman44

what nobody realizes is that the egr is only activated at partial throttle... removing it will not give you any more horsepower...

and i did have everything hooked up electrically on my block off.. i had a relay that would send lift sensor voltage thru a resistor and back. in my case it had nothing to do with the ecu not recognizing the egr... you have to realize that when the ecu "thinks" there is an egr valve functioning it expects certain engine conditions and modifies output accordingly

in the case of an engine that was designed with an egr running with an ecu that was not there are conditions present in the engine that the ecu does not expect... I'm just speaking from experience - when I removed my block off plate my engine ran a hell of a lot smoother

kornerk12

This is also true

malugud206

ill check my firing order on my distributor cap i were u i had that same problem... if u put ur 1st cylinder on number 1 ur cap should be also on 1 so just make sure its on the right firing order that could cause that misfiring

95Sedan

Did this fix your problem? I have the same issue with a slight missfire at idle
Sorry for bumping the old thread but want an update.

My EGR is there just no lines connected to it or electrical harness.
1992 h22a4 swapped EG OEM + p28
it runs good after you rev it alittle bit but it's rich. you can see and smell it.
i'v been messing with timing from the dizzy too.

holmesnmanny

What makes you think you can take any ecu and use it in any other car that Honda has ever made in its history and that car will run fine ? I would really love to hear your answer.

95Sedan

Oh I have no idea that's why I asked the questions. IF you were trying to reply to me.

holmesnmanny

if you're going to use the p28 it needs to be chipped and tuned

95Sedan

Thankyou