Gerhard

I performed a swap to an H22A from my old H22A4. (Turns out I probably could have just done the rings on #4 and #1... but it was fun, so why not?)
I'm now seeing a misfire code on cylinder #1 every now and then.

I've got good compression numbers (1:255,2:258,3:260,4:255) and a leak down test shows every cylinder is at least 95% or better (5% loss or less...).

I cleaned the cold idle valve with crab cleaner shortly before I did the swap.

I've repalced injector #1...

I've adjusted the valves... and used .172mm across the board as I don't have a good set of feeler gauges. (I adjusted the valves to this spec after I noticed the misfire...)

I'm not positive, but only tend to see the code thrown when my foot is off the accelerator in the low RPM ranges... (Ususally coming down from higher RPMs or in low RPMs in 5th gear...)

What would cause a misfire only in #1??

I'm at a loss...

Gerhard

marcucci

When your foot is off the accelerator, or just decelerating with your foot still ON the throttle. There is a big distinction as far as the ECU is concerned. If there is ANY throttle input, the ECU will NOT cut fuel (lift throttle fuel cut).

You have the USDM oil pump and crank sensor, correct? How often does the code come up? How long does it take to appear once clearing?

sharkcohen

First thing that comes to mind is that aftermarket distributor you installed.

Can that fancy scan tool that you have display the ECU freeze data? If it can, I would check it out for any irregularities.

What about the #1 spark plug? #1 wire?

Misfire is determined by monitoring the CKP sensor. I would assume that you moved your factory CKP sensor to the JDM motor, perhaps something went awry with the sensor?

Gerhard

Marcucci: Normally noted when I taken my foot off the accelerator...

Shark: I'm using the OEM distributor, I replaced the ICM. Plug one is an iridium plug, and the wires are new NGK's. (New cap and rotor as well.)

I did move the Crank Position sensor over from the old motor.

It happens, so far, 5 times in 1000 miles.

(A mifire is that the cylinder doesn't fire at all, right?)

Gerhard

Guys, It's also possible that I get the code at low rpms, in 5th, just when steping on the accellerator very lightly...

sharkcohen

What is the actual DTC that you are getting? Not what the MIL is flashing, but what the scan tool reports. And what ECU are you running?

Gerhard

The scan tool is reporting P0301/B (On the OTC Monitor 4000 Enhanced I've got).

Indicates Misfire Reported Cylinder #1...

Gerhard

Ok... it seems that I get the misfire when the throttle is flat. That is to say when I'm got my foot on it, but am keeping the power level. I seem to notice them happen the most then.

I have, at this point, done the following:

1) Swapped out the Control Air Idle Valve with the one off the 4th Gen H22A IM I have.

2) Replaced the injector on cylinder #1

3) Checked the cap / rotor / wire / plugs (all which are new).

4) Replaced the FPR (I had a spare I picked up with a 5G fuel rail I got from a kid cheap...)

5) Checked the vacuum hoses... replaced a few of them.

I seem to be having higher frequency of codes being thrown now...

I had the following odd symptoms today:

1) Idle at 1200RPMs... solid.

2) Idle bouncing between 900 and 1545RPMs (I know the high end number becausing the scanner was hooked up at the time).

3) MIL with Code P0301 B

4) MIL with MIL light flashing - Code P0301 B (Happened after the high / bouncing RPMS started (high - never seen before, bounce seen once before).

I'm at a loss.

So it's probably not the wires / plugs / cap / rotor / FPR / CAIV / Compression...

What the hell is causing this?

sharkcohen

What ECU are you using to run the car?

Gerhard

BTW: The order to the new symptoms was:

- Idle flux between 900 and 1500

- High Idle at 1200 (ish) RPMs

In between the two, a vacuum hose for the FPR might have popped off. (I'm damned if I know how that could have happened...) I noticed it off as I did the CAIV replacement...and I'm not sure if I pulled off.

Gerhard

I'm running the 98 Manual Transmission ECU (P5M).

I do have the Auto P5M ECU... I could swap them after moving the resistor and making it function as a manual ECU...

marcucci

I am pretty sure that a "misfire" according to the Honda ECU is NOT when the cylinder does not fire, but when it fires improperly, weakly, or when there is detonation. I am not 100% on that, I'm not sure who might be.

The throttle condition you are referring to is when the ECU is at it's leanest. You are referring to tip-in (in 5th) and steady-state throttle loading (reducing or modulating throttle input to decelerate or remain at a steady speed WITHOUT taking throttle input to 0%). In this case I would look at things like fuel delivery (any reason it should be less at this point)? , knock and EGR issues, and low ignition energy.

Follow the other tips to datalog or further pinpoint the problem if you can.

Gerhard

Ok... I'll set the scan tool to datalog on DTC? I gather that would work best?

When I think misfire, I think in firearms terminology... That's the only reason I ask.

Before you were saying the tight valve adjustments might cause codes to be thrown... what codes would those be? (out of curiosity...)

Keith

What injectors are you currently using?

Keith

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marcucci

I dont' recall without looking in the manual. If you go through the codes chart it calls out I think 1 or 2 that list valve adjustment as a possible root cause.

I doubt the adjustment is the root cause in this case, but you do need to eliminate it as a potential source.

Gerhard

Stock 290cc injectors...

Valves second thing on the chart... maybe I just suck at adjusting vavles? As I said, i used a .179mm feeler for both the intake and the exhaust... Maybe that was a bad idea?

marcucci

Stock should be 280cc, not 290.

.007" I/E should not be an issue. It's not right, but it shouldn't cause an MIL by itself.

What kind of fuel do you get up there? OK, or crap?

Gerhard

Well, I've been trying different fuels. I put an octane booster in the fuel initally. Now that you mention it, I might have started seeing more of the MIL's (in frequency) after the last fill.

Opps... so, yeah, OBD-II Stock injectrs... 280cc... I'd say on the whole the fuel is good.

I guess I'll swap out the wire and the plug. I'm wondering what else it could be...

With respect to the valve adjustments... what, exactly, should I do for the intake and exhaust. I think I'll swap the distributor if the plug / wire doesn't do it. While I'm lining everything up for TDC with the cams, I'll adjust the valves properly. (You told me, but the message is gone from the inbox here...)

marcucci

My point is that you may have an issue if you can only get 91 Octane there. I'm not sure what's available in NJ.

I would recommend .006/007 for the valves.

h22 bb6

^^^ We have up to 94 available in NJ, but 93 is readily available.

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Medium Scott