OK, heres the background: 96 honda civic, sohc motor.... We port and polished the intake manifold, throttle body, and just the beginning of the exhaust manifold. We removed the entire head because we were going to do everything, but because of time restrictions, never were able to do the head.

The O2 sensor (no idea if its primary or not, its located on the bottom of the the exhause manifold) was wired up to 4 wires that were located right next to the sensor. When I bought the car, it ran just fine with it not hooked up, and we hooked it up while doing the work.

So after re-assembling everything and getting the timing belt back on, we replaced the spark plugs and gave her a shot. (no timing done)

The engine started and reved by itself all the way up to redline, upon which i turned off the motor. By adjusting the distributor by hand, we could kind of get the car to not rev on its own, but it would die after a few seconds...

Any ideas what we did wrong??

 

You ported the throttle body? Are you sure it's sealing while closed now? If not, that might be why your engine is revving itself to redline.

 

that doesn't seem like it would cause it to go all the way to redline

When I was adjusting my throttle cable I tightened it to much and it revved to 3000 rpm. I loosened it a little and it went back down. Thats a possibility but a doubt it. Let us know if you figure it out cause I'm curious what the problem is.

 

I'm with inspyral, if you "ported" the throttle body, and didn't replace the throttle plate with a larger one, it's very possible to have run-away. Adjusting the idle just threw the timing off so far that it couldn't rev easily. If that's not the problem, you most definately have air being sucked by a gasket, or have an open vaccuum port.

 

Either that or TPS? (just a guess)

 

Im not anywhere near my car right now, its just sitting in my garage 2000 miles away, but we did get a b16 throttle plate. I dont think that it completely filled the throttle body, there was at least a few millimeters on all sides. How much room should there be around the plate?

Also, do you think the O2 sensor could have anything to do with the problem? I dont think that it would cause it to rev up to redline on its own.

 

Oh yeah, and another quick question: If we took the head off and didnt touch a single thing on it, then put it back on, would it have to be timed again? I didnt think that it would because nothing on the head moved, so basically its like we never took it off at all.

 

There's your problem, the throttle plate should firmly seal against the throttle body.

 

Yup, there shouldn't be any gaps around the the throttle plate when closed. That's why Honda uses that black sealant stuff to make sure the plate gets a good seal.

I'm not sure what kind of timing you're talking about, so I'll assume it's ignition timing. Even if you didn't touch the distributer, chances are, your ig timing may still be slightly off, so it's not a bad idea to re-set it.

 

I love you guys :thumbup: