You have the original OBDII P2P ECU for a 98 EX but the swapped engine may be from an older OBDI Civic, which would cause the ECU to look for sensors that are not there. The previous owner may have disabled the CEL to mask this potential issue. When you turn the key to ON(II), the CEL (see my avatar picture) should turn on for 2 seconds and then off. If the CEL never turns on, then it may have been disabled by removal of the bulb in the cluster.

 

Oh ok the cel (check engine light) yes it comes on and goes off like you stated ........how can figure out if I have the right ecu?? I really apreciate the help.

 

As you don't have any CEL codes, the previous owner must have rewired the system correctly.

 

Ok I guess that is good ....so should I replace the thermostat and bleed the system???.......thanks

 

If the engine is running cold, then definitely replace the thermostat and bleed the system.

 

Ok I will do that first.....where on the gauge should the needle be to run normal?? And is it ok to drive the car cold and at those rpms???......

 

I think you can put a D15B into a stock EX if you only use the block and the head, keeping the manifolds and all the sensors from the EX.

It's OK to drive for a while cold like that, mostly what happens is the ECU puts extra fuel into the engine (to keep it running more smoothly until warmed up), wasting gas. Your oil will also sludge up faster. Normal reading on the gauge is about halfway. It should come up to a certain point and stay there regardless of outdoor temperature or driving conditions.

 

i think you guys got me on track here ,..i started my car 15 minutes be for i left work and turned the hot cold bar on the ac to cold and left it off most of the way home (40miles) and it ran at 26-2700 going 70mph all the way but i did turn the heat on for a sec and after 2-3 min you could see the temp dropping so i just put it back and drove the rest of the way ,......we will get it changed out this weekend ,..just 1 more?? if i may,....should i use a ,..170 degree 180, or 190, ??? sorry about all ?s just wanna be sure ,....i don't know much about it that's all ,.....i really do appreciate all the help

i will update as soon as i get results.

thanks again

 

I think that stock is 190 or 195, use the stock temperature one. You aren't doing any favors with the colder ones.

 

ok heres an update,..........i replaced the thermostat put a 195 in there it had a 170 in it ..but it runs good now and the rpms are down but now when i stop it feels almost like it dies and the rpms go down to 500 ish (it dont die it seems like it did) ,....is this normal??.......and also the whole car stats vibrating after i sit still a minute or two,...what could that be ?? i will replace the plugs and wires, cap,rotor button, tomorrow if you guys think that will help....not sure how old they are anyways ,..................again i do really appreciate the help.