EG_SINZ

posting for a friend

quick questions before i dive in. long story short my head timming was 180 off of my crank pully tdc. so im pretty sure my valves are bent because we started the car like this. ran like **** but ran. so i did a compression test and every cyl is 200-210?... if i have bent valves should i not be getting compression? car is now all set up right but still wont run right. no smoke or knocks just wont idle or rev up. i have bought just about everything to do a head job but before i pull the head i just would like to know has anyone else ever bent valves and still had compression?

car idles like its missing. if you try to snap the throtlle its sucks air and dies out. you can slowly rev it up and it clears up a bit but not much. i had my timming checked to make sure im not out a tooth and he said it good. when i put my timing light on the crank it looks like in 30 degs advanved. as in im the same mount of space away from 16deg mark as its away from tdc mark. engine code 9 is coming up. obd 1 comp and moving the cap does not bring me into spec

whitaker_1991

Usually a compression test won't tell you very much about bent valves because the engine is not turning very fast. What you could do is a cylinder leak down test, but if you don't have a cylinder leak down tester you can do a dynamic compression test. When you do the dynamic compression test the engine will be running and you will compression check one cylinder at a time. Running at idle your compression should be half of the cranking compression and when you snap the throttle it should go up a little bit more.

kchungb17a

Ignition timing can only be correctly checked and adjusted with the engine at operating temp and the service connector jumped. It should be at 16*BTDC +/- 2*. That's it.

Bent valves will not keep the engine from reving. You may have a rough idle, but off idle, it should run ok. Reduced power, yes, but it will run all the way to 8k rpm. Compression may still be ok. Only way to be sure is to do a leak down test, but at 200-210, you are pretty close to spec.

Code 9 is for the CYP sensor. I believe that's in the distributor. Are all the components the same OBD series? Is the distributor OEM?

I'm not sure what you mean when you say your head timing was 180* off. The cams spin at half the rate the crankshaft does, so to say your head timing was off by 180* only tells me you were looking at your cam timing when your engine was at TDC for cylinder #4 instead of #1. In other words, if you spun the engine another full turn (counterclockwise, of course), you should be at TDC#1 with arrows on cam gears pointing straight up. If that's the case, your timing was not off and you (likely) did not bend any valves.

It is more likely you have a simple driveability problem. What ECU are you running? Is it a virgin ECU? Do you have an OEM distributor and OEM wires with B18C1 spec'd NGK plugs? How is your fuel pressure? You gotta go back to basics.

whitaker_1991

My bad! I did not see that code 9. You should probably try to fix that first. The only thing I can think on the cam timing off on 180* part was they had the cam flipped upside down and tried to start it. Seen that happen a lot when customers think they can fix there own car, but every time it has happen they also just get a new motor for it and I never bother to see if the valves actually did mess up.

beecee18

Its also possible for the vtec solenoid to be stuck open and running off the high cam all the time, check pressure at the solenoid service port on the cylinder head.

Or swap out for a known good solenoid for testing porpuses,
this just happened to one of our builds and netted us that same symptoms, and code also. but only after trying to start it repeatidly

Solster

ok first off if Both cams are 180* out from the crank then you will be fine.

keep in mind when you set the cams and crank to TDC and rotate the crank the cams will be 180* when the crank turns the first 360*.
When you rotate the crank another 360* the cams return to TDC and will be in line with the crank.

now if you have air compressor and a good Compression gauge you can screw the hose of the gauge (make sure it doesn't have a One way valve) into the head and connect the hose to the compressor.
Now eather make sure the Cyl is at TDC or lossen all the tappets so NON of the valves are open. you have put your ear to the throttle body and hold open the butterfly if you hear a Hiss the valves are leaking on the intake side. if nothing hold your ear to the exhaust pipe if you hear a Hiss the exhaust valve is leaking if not move on to the next cyl