Hi all, I purchased a 1997 Honda accord 2.2l VTEC A/T. when I bought it the car would start but it created plumes of white smoke. after a compression test it was clear that the head gasket was blown between cylinder 1 and a coolant passage. I pulled the head, and sent it off to a machine shop to be milled, pressure tested and cleaned. I got the head back and they said there was no warpage, and no cracks in the cylinder head. while the cylinder head was off I went ahead and threw new rod bearings and piston rings on the engine, and replaces all the gaskets, seals and timing belt along the way. I also threw in new valve seals and adjusted the rockers. I threw everything back together and it fired right up. However, when I got the car out on the street it had no acceleration and when the engine reaches between 3500,4k RPM I get a dead misfire on all four cylinders. The RPM where this happens is not always the same, sometimes its at 3500RPM, sometimes 3700RPM and sometimes as high as 4200RPM. I started with the general diagnosis procedure. I checked faults and sure enough I had a misfire on all cylinders. but no other codes are present. I started by replacing the spark plugs and wires, they were old and needed replacing anyway. I then tested the distributor and there was alot up buildup on the cap so I went ahead and replaced the cap and rotor. None of these things fixed the issue but they were all due for replacement, so I went ahead and replaced them anyway. I checked spark on all the cylinders and everything looks good. So at this point I am sure the ignition system is good. over time while diagnosing the issue I found many things wrong with the car that I wanted to replace, regardless of If it would fix the issue because the car has over 240k miles and I want to get all the repairs done and make the car last. At this point in time I have also replaced the fuel pump, fuel filter, all fuel injectors, the fuel pressure regulator, Throttle position sensor. I figured after replacing all these things one of them would have fixed the issue, but it didnt. im still having the same problems.
I recently checked the MAP sensor and at idle i am reading 1.7V, I read where at idle the voltage should be between .8-1.1V im thinking this is likely due to a vacuum leak somewhere, but im not sure that a vacuum leak would cause such a missfire. Im planning on using the smoke machine today to try and find a leak somewhere.
any ideas of things to test, or other known causes for these symptoms would be helpful.

other pertinent information:
Compression test dry results
1: 150
2: 150
3: 150
4: 145
checked cam timing with timing light
I do have access to a high end scan tool and can get any PID data that I need as well as I have some special functions and tests I can run.

I am at my wits end on this car. and If i cant figure it out soon I may just take it to the Honda dealer down the street and pay their diag fee. I dont really want to pawn the problem off on someone else but It seems like my last resort.

 

What plugs and wires are you running..honda are picky with its ignition system...timing is non adjustable after 96 on these accords..hopefully someone will chime in soon..keep us posted...

 

was the rocker assembly installed when it went to the machine shop?

 

Probably a large vacuum leak. Use the carb & choke cleaner or starting fluid test, start it up, let it idle and spray the vacuum lines and fitting where there could be a leak, listen for changes in RPM, if it goes up, you got a leak there.
Honda's PGM-FI system is a speed/density type fuel injection system that uses throttle position & manifold pressure readings to calculate fuel delivery, a large enough vacuum leak could cause fuel pressure regulator problems and manifold pressure problems.
Also check the ignition coil.

 

Verify the engine harness main ground is properly attached on the end of the manifold.
Check the boost chamber on the plenum on the back end of the intake manifold as well.
Depending on options, there is usually one or two capped off vacuum ports. While working on the engine you may have dislodged a cap or damaged it. Verify they are all there.
Verify you have reinstalled all your vacuum lines correctly. B1 engines have a few extra vacuum controlled components for the air injector system as well as the air intake resonator assembly.
Verify the PCV valve is working correctly and hoses are connected.

 

^ Dude, MAD MIKE, thats what I think we ALLLL wanted to hear, that something that comes as easy to you as it does to others? lol, you honestly seem to like, "just chillin on a porch" talk these forums. I mean, you get it

Main harness ground is crucial, easy to overlook, good recommendation. It could be, though unlikely, the ecu too. It could be a kind of freak problem with it, like reference voltage output/regulation to sensors or a fuel injector driver circuit problem. Not to worry you, just a possibility.

Yeah, I don't have all that much to add really