my buddy blew his engine in his 99 civic i don't believe it's an SI. but he got a 98 engine. we put it in and it starts but won't idle right because of the IAC. the problem is the 98 intake matches up to the block fine but the IAC is different and we could splice and swap the connector but the 99 harness has 2 wires and the 98 intake requires 3. we are thinking about machining the intake so the IAC can be swapped. the other problem is the 99 intake that works with the connectors for the IAC doesn't match the block so we have a huge vac leak which causes the idle to be all over the place. is there a adapter gasket seal that we can use. the 99 and 98 seal don't work with this set up. any info would be helpful.
thanks

 

I'll make this as simple as possible....there were 3 basic engines in the 6th gen civic: The B-series was in the Si (DOHC), the EX was a Vtec D series and the rest were non-vtec D series of some sort (with the exception of the E-Vtec trim that I don't remember). The intake manifold is very different on all three. The EX and Si are horizontal inlets and the rest are verticle. I believe the airboxes were different also.

Your best bet, get the engine code f/ the front of the block and let me know / search. Then hit a junkyard for the correct one. They'll probably even trade for the one you have.

 

i can't help you out, but i'd just like to comment. i thought it was illegal(in most states) to install a motor that is older than the car. in your case, you can install a 99 and up engine but you can't install a 98 and lower engine. some one correct me if i'm wrong. and sorry if my question ends up hijacking your thread.

 

if that was the case, then k20's and all b series motor swaps would be legal in EF's, EG's and EK's .... but its not...

 

i'm not sure but he was short on cash and the 99 engine was 1500 and the 98 was 800 and only had 74K on it where the body has 143K. we have tried swapping different year intakes on it. my first suggestion was for him to not be a cheap ass and get a 99 engine. he does have a non vtec i believe and if it is a vtec you wouldn't know it because he weighs 360lbs haha. but thanks for the info xscaraudio.

 

oh and you can install whatever engine you want into any car. it just gets emission tested for the year of the chassis. so if you have a 2008 s2000 and you decide to put in a 88 chevy 350 with a blower it gets tested as if it were a 2008 which means you fail. also because it has to have the original equipment on it. so lets say your car has an air pump and for some reason the older or NEWER engine doesn't ...you fail even if it produces less emissions because it doesn't have the original equipment. hope this helps clear some things up!

 

I don't know how the rest of the states are, but in California, you cannot install an older year engine into a newer chassis. The engine has to always be same year or newer.

If I'm correct, last time I talked to the Honda dealer, the 98 and 99 civic had two different computers.

I would take the intake manifold and intake off the 99 and adapt it to the 98. That would save you a ton of headache, because all the sensors would be the same.

 

yea i told him to do that too but he is short on cash. my comments were this in order
1. you should have bought the 99 engine
2. you should have bought the harness and the ECU for the 98
3. you need a second job
4. I would have checked this before i installed it if you would have paid me to install this rather than saving money on a dude that has never done it
5. put honda bond on the intake and pray it holds the gap closed

i'm not sure about cali but in pa we can do kind of whatever we want as long as it "passes" emissions
i'm going to just push for him to let me pull the 98 out and get his money back and get the 99 or just putting the money up for the 98 ECU and harness. thanks for the info