I just put a JDM "under 50k" motor in my 1994 accord. (f22b non-vtec)

Runs great-wont idle once warm, I also have to press down on the accelerator to start. It idles around 4-500 rpms once it's warm, but it wont hold steady. Idle goes lower until it stalls. Sounds and idles like it has a slight misfire.

When I pull up to a stop sign, I push the clutch and brake...the rpms drop...about 1000rpms it revs up to 1100rpms then drops down to 4-500...some times down to 1-200 and recovers back to 4-500...other times it dies.

Occasionally it will quick rev from 1500-2k rpm while cold...but not a consistent occurrence.

I have scrubbed the Throttle Body clean, also removed the IACV and cleaned the screen and water passages. I am not getting any codes currently. I did get 12-3-7 but have pulled my battery to reset.

12-I think is egr...not so sure
3-I think is Maps (I unplugged while running)
7 I think is TPS (I unplugged while running)

I currently have a vacuum line unplugged on purpose to get it to keep running during idle. (it's the 1 on the driver side of the Intake manifold facing the firewall-goes to a canister on firewall on passenger side)

I have ran the idle screw both directions with no change. While it's cold it idles high almost 2k rpm...once warm it dips to 4-500 rmp and had slight rumble.

 

It is easy to accidentally switch the electrical connector for the map and the tps sensor, because they have the same electrical connector.

The wire colors going to the map are:
1. yel/wht
2. grn/wht
3. wht/yel

Make sure the connector with those colors are not plugged into the tps.

 

After checking that the tps and map are connected to the correct sensor.

Check for vac leaks.....any gaskets (intake or tb), vac lines, pcv hose or valve to cover, ect.....

 

I did notice that they are the same plug...Thank you..I confirmed they are correct before responding. (also my wiring harness is set up so they clip streamline.

 

The only vacuum leak I have currently is the 1 I forced. I have sprayed brake cleaner on all my vacuum connections and visually inspected, as well as around my TB.

 

I bled the coolant...and still smell coolant (no leak that I can find) I replaced the radiator cap just to know it's good.

Replaced plugs/wires cap/rotor and gaped the plugs to.40

Pulled covers off to triple check the timing. Cam & crank both line up TDC. also balance belt lines up to it's marks too.

 

WOW just filled up and the MPG is terrible. I can usualy get 400 mile a tank +/-

This has been a problem for a week and only got 300miles on this tank

PLEASE throw out some more idea's

 

Do you still have the original motor?

Also, try tapping on the IACV with the handle of a screwdriver. See if that will change the idle.

I think there will be a sticker with the vacuum hose routing. I would double check that you have have the hoses connected properly.

Maybe check the fuel pressure regulator to see if you have switched the supply and return hoses?

I'm just trying to throw out some simple suggestions.

 

Yes I still have my old motor, I have tried each of the IACV's...and cleaned them both out. I am curious about the fuel regulator....where is that? I haven't checked that yet.

And thank you sooooo much for any suggestions....this is driving me crazy. I am learning to be a Honda guy, My thing is rock crawling and that's all about metal fab, my Honda is my daily driver

 

It is bolted to the end of the fuel rail on the passenger side. It will have a vacuum hose going to it. Pull the vacuum hose to see if you have a strong smell of gasoline.

I would download a 94 shop manual. Go to the common diy thread on top of the gen tech form. There is a link to online shop manuals. That will have much of the information you will need.

The vacuum hoses will show the routing. The electrical section will show the location of the grounds.

Clear the codes by removing the 7.5 amp backup/radio fuse in the engine bay fuse box for a minute. Take a test drive, then recheck for codes to figure out is one of those codes you listed is a real error code.