angrysmileyface

So I have a 1995 Accord Ex wagon running rich The engine was replaced with an F23 block/head but uses the original F22B1 intake manifold about a year ago and has about 7000 miles on it. I purchased a hondash reader for the car (its OBDI) and so far the readings coming from it indicate a fairly rich set of circumstances even though there is no cel. Short term fuel trims are like +10% or so at idle even. (Not really sure how to get the Long term ones) o2 sensor rarely if ever reads above 1v Engine idles around 750-780 and temperature seems alright between 190-207 degF Only other things of note are something seems to be running down the battery, but I couldnt find an amp draw on it above 20ma. The engine has a very pronounced vibration and the D4 light flickers with the turn signals and occasionally the tach/speedo blip to 0 with the engagement of the turn signals (This is probably a bad ground of some sort)

LukeM

Check your TPS calibration.

angrysmileyface

TPS calibration is good.

GhostAccord

According to the STFT, the engine seems to be running lean and the ECU is adding 10% more fuel.


Reasons for ECU to demand more fuel;
Dirty/fouled O2 sensor
Leak in the exhaust before the O2
Vacuum leak somewhere in the intake track, behind the throttle plate. leaking o-ring or gasket, cracked vacuum hose, throttle body jammed open with carbon, or a leak in the fuel injector air control system.

There were some F22B1 and F23A engines that have an air injection system. The ports feed air to the fuel injectors to aid in fuel atomization. This port goes from the head to the intake manifold and ends at each injector bung in the intake manifold. If you are using the intake manifold or gasket from the F22B1 that does not have these ports, it will cause un-metered air past the injectors, aka a vacuum leak.

angrysmileyface

I will have look at the manifold that came with the F23A when i got it.I attached it to my old F22B1 when I pulled it. the engine does not have any indicator of it being anything other than F23A since there is no sub desginators on it like F23A1. What does these special ports look like.

angrysmileyface

Is the FIA that angled down port on the passenger side of the front of the F23 intake manifold? If so, the engine Im currently using has that port on it as well as my OBD1 F22B1 had it too. Im still using the F22B1's original manifold, and do not have surging or idle above ~750-775 rpm with no load. Other than some vibration, the engine really doesnt seem to be behaving poorly. I will see if there is another leak in the exhaust. I just replaced the B-pipe because after 20 someodd years the welds around the resonator chamber had broken, but if I recall, this is way after the 02 sensor.

GhostAccord

OK, so the question is, why do you say your car is running rich? Is the +10% STFT causing your exhaust to smell of unburnt fuel?

Are you having poor mileage or engine performance issues?

angrysmileyface

Tip seems overly black, milage isn't as good as it's been in the past. Not sure if I need other other thibgs to investigate