(CRX Si with a D16Y7 MPFI OBD0) Driving down the highway and lost cylinder 1.. Managed to get home on 3 cylinders and found the spark plug covered in fuel. No CEL. I replaced the plugs, wires, and swapped a known working backup dizzy in but nothing changed. Since it does seem to be getting fuel in there, should I bother messing with the injectors or resistor box? If not, what should I look into next?

 

Hmm, zero compression. I guess a stuck valve...

 

or broken ring, or the valve dropped. good luck

 

I popped the VC off and don't see any damage, but it looks like an exhaust valve is hanging down a bit when I looked into the spark plug hole. Already filled the cylinder with string and am removing the rocker arm assembly. I can get a replacement head from the wreckers if I need to but figured I'd try to repair first.

 

I have also seen valves have chunks break off the face as well. The bottom end was typically fine but the valve seat got ruined.

 

Is the spring destroyed?

 

when you say hanging you mean its not closing all the way, like there is a gap between the rocker tip and the top of the valve stem then that means that the valve is bent its stuck in the valve guide

 

Well this is weird, I pulled the spring off the valve I thought might have been stuck but the valve seems to move freely. No damage at all. I guess now I have to pull apart the other three to check them. I've also got an air compressor I can try hooking up to see if air comes out the valves but this will have to wait until tomorrow.

 

OK it seems I'll never catch a break with this stupid car. I discovered it is actually both intake valves that are stuck open after I put a flat piece of metal across the tops of all 8 intake valves. HOWEVER, the string I put into the combustion chamber to hold the valves while I removed them is now somehow caught on something and won't come out. I'll drive it on 3 cylinders before I bother removing the head, so anyone got any ideas how I can get that crap out? I did rotate the motor a bit to see if it would come loose but no.

 

How thick is the string? This might be horrible advice so I'd wait to hear from someone else, but if its really thin string you could just start it and it should probably either burn up or get shot out the exhaust.

EDIT: unless you mean you filled the combustion chamber with string, in that case yeah don't start it, lol.

 

It isn't very thick stuff, just cheap nylon crap you'd tie down a tarp with or something. I'm not sure how much of it is actually stuck in there as I did remove a bunch... And believe me I am tempted to just fire it up haha

 

You know what, I think it wedged itself up into one of the valves that are stuck open.. If I pull the springs off those and get some movement on the valves maybe the string will come loose. I'll try that shortly.

 

Good luck man!

 

yank the head off of it see if the valves are bent or burnt if bent throw a few few new valves in it hand lap em in and throw it back together, that head should take you no more than 1 hour to take off, if you have done a few, about 30 minutes the head can be off.

 

It wouldn't be worth the effort removing the head honestly. I've got a backup 90 integra with air conditioning I would be driving if this doesn't work out while I build my new motor. The D16 is getting yanked pretty soon so I have a hard time justifying too much work on it.

LUCKILY, pulled the intake valve springs off and the string is now out.. Plus the intake valves are back up to the same level as the rest. I'm about to shoot some air into the cylinder to see how it holds.

 

Out of all the local auto parts places, seems I can't actually find the air attachment to fit the spark plug hole. Guess I'll be cutting a compression tester in half tomorrow or something...

 

Why don't you just stop doing stuff half way and purchase a leak down tester?

 

Nobody sells those locally and I primarily wanted to fix this for zero dollars.

Anyway after new valve seals and making sure the valves were all at the same height, there is no change to the problem. I won't know if the valves are stuck again until I pull it all apart again. I think screw this I'm going to daily drive my old DA and finish the B18C...

 

Do you have an air compressor and a blow off tool or remove the end to allow sir flow? If so...

***WARNING GHETTO TRICK - SHIELD YOUR KID's EYES!***

1.) Remove spark plug from cylinder.

2.) Take hose and wrap cloth around it in a fashion to kind of seal it to the spark plug tube.

3.) Try to use the lowest pressure where you can't hear the air leaking at the input but can hear from where it is leaking out.

Of course you need to be on the compression stroke and follow the basic rules on leak down checking as well. If the valve stems are even I am going to guess a broke valve, badly burnt valve, extremely worn seat, or (doubt it) hole in piston. I lean towards broke valve.

P.S. - Valve stem seals have absolutey nothing to do with compression.

 

I might try that. And yeah I know the valve seals don't have any relation to the problem but mine are worn out so I figured I would take care of them too.

 

Might as well let you guys know what the problem was. I finally pulled the head off today after spending all my time fixing my backup car as it was falling apart (literally). Burned up one of the valves. The rest of them look a little cooked too so I'm just going to swap them all with junkyard spares. I'll have to keep an eye on my plugs because it seems I'm running lean.

 

Hey - I called it! Are the seats messed up too? If not, then be sure to lap the replacement valves properly or you could wind up being in the same boat. If you don't already know how then just ask.

 

Haven't pulled the old valves out yet. What should I be looking for?

 

Deep pitting, dark gouges (actual burn out), seat could be sunken from being worn so much, look at valve margin (face = flat part u can stand the valve up on - margin is the thin strip 90* then turns into valve seat), check stem while you are at it for gouges, ect...