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Tuning Stock F22B1, Runs Rough with Neptune RTP

5K views 12 replies 5 participants last post by  cervan 
#1 ·
I have an Accord that is a stock F22B1 that runs great on the stock ECU. I made a base tune using some F22B1 maps I found online, but even with it warmed up it idles very rough (like a big cammed engine with 10 inHg vacuum at 900 rpm). The AFR is about 13-14:1, and any change in ignition timing doesn't seem to help very much.

I tried one of the Neptune "tuned" files, and there was a F22B1 stock NA tune and the car still idles really rough. At rough idle, I actually pulled out two spark plug wires and it still ran exactly the same; shouldn't it die if it's idling that rough?

I hooked the stock ECU back up and it runs perfectly fine. I tried changing a lot of settings and it wouldn't idle any better. The car revs up fine, it just idles really bad.

Any advice or ideas?


1996 Honda Accord
F22B1 all stock
SpeedFactory OBD2A-to-OBD1 ECU
P06 ECU with VTEC Components and Moates Demon (used on other cars without issues)
 
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#3 ·
the timing is indeed adjustable.

download a manual for your accord, and go through the ignition timing procedure. have a timing light handy.

I believe the moutning of the distributor allows approx 10-20 degree range. it accounts for distributors not all equal in terms of sensor location inside. Its also pretty much the ONLY way to get an ebay distributor to run properly, as many out of the box freakin such

EDIT short version is, have engine warmed up fully. shut down, remove key from ignition. find 2 wire plug near ecu location, called a service plug. generally blue or green, might be grey. bridge those two wires together via a paperclip or small section of twisted wire. go under hood, loosen distributor mounting bolts enough to be able to rotate distributor by hand, but not enoguh to be loose on its own. fire engine up, let it idle, and use a timing light gun to see where you are at.
 
#4 ·
OBD2 distributors are non-adjustable since the TDC and CKP aren't in the distributor. If you try to change the distributor orientation you just get a CYP sensor error code.

I was able to test with an OBD1 Accord with same F22B1. My ECU (with demon) installed in the OBD1 accord ran just fine, and I took the stock OBD1 ECU and put it in my accord and it ran really bad like normal. So now I know there is something wrong with my car.

The only thing I could come up with is that the OBD2 distributor just won't work when I convert to OBD1. Tomorrow I'm going to get an OBD1 distributor and try that. I was told the OBD2 distributor would work. Have any of you used an OBD2 distributor when converting to OBD1?
 
#7 ·
SpeedFactory OBD2A-OBD1 ECU Adapter Harness

I don't know if Civics are the same, but I have the TDC and CKP sensors on by the crank pulley and I guess the Cylinder sensor is in the distributor. I guess if I use an OBD1 distributor I would have to move the wires for TDC and CKP to the distributor, is that what you mean?

I originally asked Rywire what I needed and they told me to just get the ECU adapter harness, and I could keep all the OBD2 components. I bought the Speedfactory harness only because they are local so I could get it faster.

I kinda figured it would be like my OBD2 civic. I have adjusted ignition timing on that, as the ebay distributor I am running was an absolute turd until timing was properly adjusted.


perhaps accords were treated a bit differently? I dont understand why they would.


Do you have a 2.3 vtec head? those only have 2 mounting holes it seems, and would fit the issue of nonadjustment.
I have a F22B1, but the 2.3 VTEC is very similar. In the FSM it says that if ignition timing is wrong, replace the ECU instead of being able to adjust.

There are three mounting holes, two are slotted like normal but the other is a 8mm hole (bolt fit). If you remove the standard 8mm hole bolt you can rotate the distributor, but timing doesn't change and the ECU thinks there is a problem with the CYL sensor.
 
#6 ·
I kinda figured it would be like my OBD2 civic. I have adjusted ignition timing on that, as the ebay distributor I am running was an absolute turd until timing was properly adjusted.


perhaps accords were treated a bit differently? I dont understand why they would.


Do you have a 2.3 vtec head? those only have 2 mounting holes it seems, and would fit the issue of nonadjustment.
 
#8 ·
I tried the OBD1 distributor and it didn't make any difference, it still ran rough. I could adjust the ignition timing, but the timing was far off and getting it close didn't have much affect on the engine. I'm going to talk to Speedfactory tomorrow about testing their conversion harness, because I don't know what else it could possibly be.
 
#9 ·
I was able to get it figured out.

I tried a whole new adapter harness, and going over all the wiring diagrams to try to find a discrepancy. I realized that something seemed to be wired differently in the 1996 Accord, and it was likely one of the emissions components. So as soon as I unplugged the EGR components, the engine ran perfectly.

There must be a difference in the EGR wiring that causing the ECU to get false readings on another sensor. All I know is everything is perfect now, so I can finally tune my car.
 
#10 ·
I know some tuning software/solutions allow interacting with the EGR connector, as far as using it for something else. I fail to remember if it can be used as an input or output, but maybe check some menu's for EGR options. perhaps you can find a use for it.

those damn emissions crap! always causing a hiccup
 
#11 ·
I believe EGR and secondary o2 sensor wiring is switched about in 5th gen accords. Been a LONG time since I messed with those, but the adapter harnesses are typically built on civic/integra diagrams not accord ones and they tend to have issues on the 5th gen accords due to those wires being swapped around.
 
#12 ·
That is what I read also, but it is only the OBD1 accords. Even then, when I tried the P06 ECU with Demon in my other OBD1 Accord it ran perfectly fine with no error codes. So even if those were switched around it didn't make a difference.

The OBD2A wiring diagrams show exact same pin locations as Civic/Integra. Since I was using a P06 ECU with OBD2A-OBD1 harness, it shouldn't of been a problem based on this.
 
#13 ·
you can adjust the zero point in neptune to offset ignition timing errors, basically lock the ignition timing to 16* or whatever number you want and then check with the timing light, if your off adjust your zero until it matches the timing light. and do not forget to unlock ignition timing or else you could seriously damage your motor while under boost.
 
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