Long answer, painstaking work, or paying somebody else to do it, sure if you want all that work and spend money and down time.
Would like to drop / hack in a CRV drivetrain in my integra, but don't have any where near the money to do so.
Also, Bad spark plug wires will cause stumbling when you really step on it, had it happen to me on 3 different cars. It also seams to be constant, not random.
I'll check it when I have some time, thinking about redoing the wiring harness because somebody that swapped the engine before I got it left all the mounting brackets for the wiring harness off.
Edit: too the car for a drive in the mountains, Had quite a few problems with it then it went away...
I got the same hesitation problem, but also the car is very hard to start to now.
It seams to be hard to start almost all the time, and also stumbles on acceleration except for really slow acceleration.
Can kill the engine when I really step on the gas (fuel pressure spikes to about 42psi when...
Check Spark plug wires those can go bad and cause lack of power.
also for lack of power stuff for where to start looking http://www.clubintegra.com/board/showthread.php?t=87424
The tensioner, it spring loaded, so pull it all the way down to release the tension and tighten down the bolt to hold it in place, then after you get the belt on release it and let it take the slack out of the belt.
First thing, Double Check everything you touched when doing the head gasket replacement. Check for Fuel and Spark and Compression.
Their is a ground wire running to the valve cover to the front radiator support, not sure if your valve cover has a separate bolt hole for it.
Check and make sure...
When you say pulls do you mean the car is pulling one side when accelerating or sometimes it has power and accelerates good, and other times the car won't accelerate good?
Also if the car is pulling to one side, Lift the car up and wiggle the front wheels around up and down and side to side.
It...
If you drop some oil into the spark plug holes it smokes for quite a while.
Recommend Testing it first before you do anything. First Step in fixing anything Verify the source of the problem.
go to the the junk yard and pick one up or is it on the bottom of the injector because that's different. Broken one on another injector once.
Filter sits in top of the fuel injector which goes into the fuel rail, also some times you don't even need to remove the fuel injectors from the fuel rail...
Go stick the bolts down in the holes but don't tighten them.
Then you can see which ones are too short or too tall and move them around till you find where they go.
Or it could be the threads that are longer than try finger tightening the bolts till they stop.
Also you Cylinder Head could have a...
First thing Check your fuses. Never Hurts to check them one by one.
Fuse No. 4 is a 10 A fuse for your left low beam.
Second, Check your driver's side headlight Bulb, it has both high and low beam in one bulb. So Generally the Low beam burns out first.
If your bulb is good Check for Power and...
You have to remove the cable that goes to the speed sensor in the instrument cluster. That is what is holding it in after you have removed the 4 screws 2 at top 2 at bottom
The Cable goes to the transmission its on the rear top of the transmission, right below the throttle body, near the rear...
RE Edit:
Ok before I start jumping off on tangents and stuff.
What is the last few things you did to your car before this started happening, Even if you think they are unrelated list them or a month or 2 off or more.
Some Things you may want to check.
Also are your tires Round, lift the car...
So it shakes really bad in the steering wheel? and did you get a 2 wheel or 4 wheel alignment, because I know my car shakes because I haven't aligned it yet.
Also your cars Wheels do they fit centered on the hub or do you need the lug nuts to center your wheel?
I had shaking caused by that...