Me and my father just dropped in a new engine because the old one blew on me.
We got a D16Y7 with about 128,XXX on it.
It is a 1999 Civic DX and im currently using it for my winter beater.

The engine swap has been done about 3 weeks ago, and ever since it was done I keep having this weird problem. It only occurs after about 30-45 minutes of driving... When I start the car in the morning, for the first half hour or so the problem does NOT exist, after about 30-45 minutes the problem starts up, so Im guessing its something with the temprature.

Anyways Im practically ripping my hair out here! We've tried everything.
The problem is that after that period of time (30-45) minutes, when the RPM is held steadily at 1,500 it... "Shakes" or whatever you wanna call it, blah I dunno. It just bounces up and down between 1,500 and 2,000. When I pop the hood and lightly hold the throttle you can hear it shaking AS WELL as see the engine shaking back and forth...its driving me crazy, when I drive, after about half an hour, when im in that area, 1,500-2,000 the car shakes like crazy, and im almost ALWAYS in that zone... Now I have to rev to 4 in each gear, and shift, just so my car doesnt shake like crazy on the road, and its such a waste of gas lol . Seriously when its in 2nd gear, and im at about 1,800 the car just goes completely retarded, like an 11 year old learning to drive manual...shakes insanely back and forth.

Videos to help explain:
(Here you can see the engine bay, im holding the throttle steadily and it just bounces, and the engine shakes, cant really see it shaking in the video but it goes back and forth like its bouncing.)
http://www.youtube.com/watch?v=X8I9KX7o93w


(Heres how the Cluster looks, when I hold the gas between 1,500-2,000 you can clearly see it shaking)
http://www.youtube.com/watch?v=JqTheAkywAM


Ahh please help! I've been to like 3 shops and they're all scratching their heads...
- Btw the intake on the car is what came with it orginally, it was on the old D16Y7 and didnt have the problem, but im still in the process of getting the STOCK intake for the car.
-Timing belt, spark plugs, all the little things have been changed and are new...

Maybe the D16Y7 is from a different year, like 97 or 98 for example, not 99, would the computer for a different year be different, could that be the problem?

Someone help...lol please!

 

wow thats weird. there shouldnt be an issue with the computers being different although you ecu could be bad...does it do that only when you stay in the range or does it do it even when your just going throw a gear and revving out the engine

 

i know this is basic, but lets start small..have you tried bleeding the coolant? sometimes air in the cooling system is known to cause an erratic idle...

 

I'd double check the timing, all vacuum hoses, the thermostat, and bleed the coolent.

 

Yes coolant has been bled and all.
It doesnt happen at idle, only wen i gently sit on the throttle to keep it at 1,500-2000.
When i let my foot off the gas completely, in neutral whether driving or standing it just sits at 1,000 fine.
When i touch the gas, its extremely sensitive, and once it hits 1,500-2,000 ... it does that, unless i slam the gas and get past that point as fast as possible, then im fine shifting at 4-5 every gear. Lets say im in 4th gear, doing 80km/h (50mph) or so, and i let off the gas completely, keep the car in 4th, once the RPM gets back down to 1,500-2,000....car shakes like crazy, back and forth, while in motion, like going over an insanely rocky road.

 

it really sounds like a throttle problem...possibly the throttle position sensor...which if im not mistaken is not servicable and would require an entire throttle body...but id try to get it diag'd completely before throwing parts at it...

 

I had the exact same problem with a car i just bought that had a mini me swap running on a po6 ecu...(bouncing and struggling at 1500rpm) so i replaced all the sensors with some off a friends car and the problem was still there....one day when i was at his house he told me that it might be the a/f ratio or wat ever its called...

long story short i unpluged the po6 then plug in the correct ecu and the problem went away!!! no more bouncing at 1500, no more struggle just smooth low rpm driving.......hope this helps good lucc

 

make shore you have no vacuum leaks

 

oh and put some gas cleaner and injector cleaner in mine did that for 2 days and i put fuel and injector cleaner in and it stopped you never know stupid stuff like that is all you need sometimes

 

loose ground or loose dizzy

 

Double check spark wire order just in case

 

tps?

 

Just searched and found this. I'm having the EXACT same problem with my B16A2 in my EJ6. Me and my boss were looking at it at work and both developed a few theories. He thinks it's something to do with the ignition system. I think it's something to do with the fuel or throttle. My car did this once ages ago after I had filled up at a station I've never been to. The problem disappeared when I filled up at a usual station but it's come back again and didn't disappear after filling up at a usual station so I'm no longer assuming bad gas like I did the first time.

here's mine about a year and a half ago:

http://www.youtube.com/watch?v=OKGzVt7tJwM

Oddly though, If I shut off the car and restart it, the problem is gone for a while. Also , it seems like there is a dead space in the throttle when the problem surfaces like when I'm driving, if I just barely let off the throttle, it violently loses all throttle when normally it'd just lose a little. I also got the jerking real bad when taking off in lower revs. I have to rev the **** out of it just to take off without getting brain damage from shaking.

 

miscalibrated tps

 

Iavc..?

 

did you ever figure out what the problem was or is??