Hello, I know this is a tuff one to answer but I was hoping someone could give me a couple ideas?......I have a '91 civic with a 1.5 Japanese engine I just put in cars starts and runs fine. but after a couple minutes ( 5 or so) the "check engine "
light comes on . Car appears to being oiled fine and all wires appear to be hooked up correctley , the only thing that seems to be possiably not working right is the
Fan has not come on yet but I do not remember how long it took before and I have not been able to drive it enough to see if it does come on ( I turn it off after the "check engine light comes on"
Any help would really be appreciated.
Thanks, Bob

 

you need to check and see what code your ECU is throwing. either go to Honda and pay 45 bux to have them check out what the problem is or use the paper clip trick to bring up how many times the check engine light flashes. the amount of flashes dtermine what problem the engine is having. do a search. cuz i don't remember the link. if you get a "45" 4 long flashes and 5 short flashes, that means you're running rich. it's a dumb code. i get this all the time. Honda still hasn't fixed this problem.

 

actually on his 91 a paper clip is not needed. all you need to do is pull the capet back on the passenger side foot well (where your feet sit) where you will see a gold colored metal plate with a hole in it, your ecu is below this plate. with your key on you will see a red light flashing through the hole in your plate (window on ecu) count the flashes to get your code and go from there

 

I am glad I found this thread I was wondering this also. I just replaced my engine in my 88 dx this w/e, I swapped it with a 91 engine. It runs great but after starting it my CEL comes instantly on. I found the gold plate and the hole but OMG either I have a bunch of codes in there or I just dont know how to count. It flashes so fast it is hard to tell the long flashes from the short ones.

 

I suggest you just go to a Honda dealership and have the professionals check out what codes your ECU is throwing out. Its is easy to check the codes by yourself providing that YOU KNOW what you're doing. One blink of your eye is all it takes to miss the flashes and next thing you know you just found out a wrong diagnostic fault code

 

Would autozone be able to check your code? They always carry some test equipment.

 

I checked and autozone only does 96+ hondas