Hi,
I have a 92 Accord Lx with 480,000 original miles. It blew a head gasket and rather than rebuild the head(it needed it), we found a used engine with 150,000 miles on it. The engine is in and runs well. We used all of the external parts from my car. The engine came out of a 1993 EX car. The engine is fundamentally the same right? (I had originally thought they were an identical engine. oops) What are the differences that might cause these issues?
My concerns are:
The check engine light comes on at about 35-40 mph and stays on. The car runs perfectly fine. I wonder if the sensor from the engine I put in is not communicating with my computer like it should. Any ideas?
The tach is being weird. At idle, the tach shows 0 rpm's and yet the car is idling fine. The tach does not appear to be accurate anymore. It goes up and down like it should, but seems to be off some.
It does have the erratic idle issue. I am not worried about that. We have fixed that before. No real issue there.

Any ideas??
I tried to read the CEL codes and cant find the little plug on on the passenger side kick panel area.

 

Not much difference. Find the plug, read the code. Problem solved.

 

The ex has a different intake, exhaust and camshaft. You can take your old camshaft, stick it in new engine. Use the old intake and exhaust.

 

Btw, the ex used f22a6, vs the f22a1 of the lx. Look and see if you have the a6 or a1?

 

Thank you. The engine says F22A1. So, maybe it isn't an EX engine. That's completely fine. We used the intake and exhaust from my old engine, as well as, the distributor. The surging idle is now fixed. We knew how to fix that easy enough. It does want to idle really low though. It has died a few times and starts right up. Most of the time it idles low, but is fine. The tach reads at zero at an idle now. It does go up as you drive, just shows zero at an idle. Driving it runs great. It seems down on power somewhat, but I have been driving my Acura lately, so I could have just gotten used to that power. I am not as worried about the power issue as I am in getting the car to idle normal. Any ideas with this new information? Thanks again for your help!

 

You probably should try to find the EX ECU... I did auto to manual swap in my 94 EX and didn't realize the 5spd ECU I got was from an LX... Car had no Vtec didn't rev past 4K and didn't run correctly... Once I got the correct ECU everything started working perfectly... Not positive it'll help your issues but I'm sure it'll help somewhere