Hi,
I have a '94 Accord LX Auto. My son was driving it when he said it lost power and died. When I got there, I got it started, but it appeared to be running on 1 or 2 cylinders. I checked the fuel pressure and it was fine and there was spark at all cylinders. I placed my fingers over the open spark plug hole and one cylinder seemed to be a vacuum while the other I checked had much higher compression....

Anyway, I have the 94-97 FSM, but I can't find the procedure to perform the real compression test (I have the gauge). Is it in the FSM or can someone point me to the procedure online?

 

There are tons of posts on here about Compression test but I will give you the short version, take out the spark plugs and install the tester and crank the engine about five revolutions then record the numbers. Add oil if a cylinder is low and retest to see if it rises significantly.

 

Thanks for the response. When I checked my boat, I had to ground the distributor wire from the coil and disable the fuel pump... I can ground the coil wire, but is there an easy way to disable the fuel pump?

 

Pull the fuel pump fuse. I don't know 94, but your fuse box lids should have a list of which fuses are for what.

Unplug the wiring harness from the distributor. This prevents the coil from firing, which is a bit safer than grounding the coil secondary wire.

 

Hi Jim, so instead of grounding the coil wire to the distributor, you saying pull the other connector on the coil, correct? That sounds like a simpler solution...

 

I unplug the wiring harness from the distributor, because my coils have been located inside the dist. That's also where the CKP, CYP, & TDC sensors are, and without them the ECU won't fire the ignitor & coil.

But feel free to unplug all the small wires from the coil. If my cars had external coils I probably would have done that too.

You'll generate a CEL for those (CKP, CYP, & TDC) but you can reset your ECU. I figure that's easy enough, to avoid the ignitor & coil firing straight into ground.

 

Well, I got the car home and did a compression test. From cylinder 4 to 1, the compression was 80, 160, 170, 0. I kindof expected cylinder 1 to be bad, but cylinder 4 has me baffled, that was the only cylinder I thought was working originally. Anyway, pulled the valve cover and this is what I found,


The cap to cylinder 1 intake valve spring was off... The valve is not touching the rocker arm, but it does move up and down. My questions are now, what would cause this? How do I fix it, and what else should I check for.

Thanks for your help!

 

So I am on the same page is it that cylinder 4 has 80 and cylinder 1 is 0. In the picture it looks like the rocker is not centered over the valve tip, is that just the photo? To know what failed you need to inspect the parts for that cylinder especially the valve spring keepers. On the 80 pound cylinder did you retest with oil to see if it gets any better. It is good news that the valve is not bent as it may not have done any more damage.

 

I think the rocker arm is centered over the valve, but the spring doesn't have it's cap so it's loose and not centered. I did try oil in cyl #4 and the compression came up slightly, but it's still low. When I did the compression test, the engine was ~40 deg F, so I'm sure that didn't help things.

Anyway, tomorrow I was going to see if I could get the cap back on that spring and then set the valve lash of all the valves and see what happens. Do I need to check anything else before I try to reassemble?

Edit: Looking at the FSM, the valve retainer has a couple of valve keepers to keep in on. I probably need to find those too? Is it possible to reattach the valve retainer and spring without removing the head?

Thanks!

 

Yes you can reinstall the parts without removing the head. It is pretty much the same as doing valve seals and there is a device to connect an air compressor line to the cylinder to hold the valve in place. You will need a spring compressor that is used for the head still on the car. Make sure you find all the parts and inspect them as something failed. I would guess one of the keepers and you may need a new valve seal for that cylinder, and the intake and exhaust may be different seals. By the compression test results not increasing with oil the other low cylinder is from the valves also. Someone may have some tips to doing the job with the head on.