I just picked up a 94 civic VX. It has the D15Z1 motor in it, with 170K miles.
It has been sitting for the past year, and little to no maintenance was done in the 20K previous to it being parked.

As soon as I got it, I did the following (all honda parts):
Oil change
plugs and wires
dist. cap and rotor
fuel and air filters
added 1/2 tank fresh gas.

I did a compression check, but I am seeing now I did it wrong. The engine was mostly cold, and the throttle was not open. The numbers were:
120, 120, 90, 120.... cyl. 1,2,3,4 consecutively.

The problem is that the car idles within spec only sometimes, but after throttle, it will drop back down to the point of almost dying. At idle, the car shakes to the point where you can feel it sitting inside the car. You can see the motor shaking more than usual, and the exhaust has a slight mis sound.

The plugs look good, not too rich or lean.

Next up on the list is a proper compression check, alternator check, valve clearance adjustment, and perhaps a throttle body cleaning. But after those are done, I am running out of ideas. Any thoughts on diagnosing this "miss" would be appreciated.


Modified by LoudLude at 1:05 PM 1/16/2006

 

how much gas was in the tank, i'm assuming less then half, since you put that in. Did you throw in premium? That gas is gonna be nasty regardless, sitting for a year, plus chances are there could be some serious crap floating around in that tank now, not being full. May want to pull out the fuel pump, and check out the condition inside the tank, and the filter on the end of the fuel pump. Also, get a proper compression done, and see what it is, you might have a bad cylinder, which would definetly cause a miss. Could be valves, or rings. My friend picked up a car that had been sitting for a long time, burned a ton of oil, and on a trip we took to ge tanother motor for it, dropped a valve, well a quarter of it anyways, best part, it made it home over 700 miles. Sounded like hell, but she ran. If your compression comes out decent, drive through that tank, and put in some premium. If you have any spare injectors around, swap those in, after you clear out that tank of gas. Good luck

 

I only put 1/2 tank high octane in, since the tank was already 1/2 full. As soon as this tanks gets low I will definitley be running some quality gas through it.

Compression test results are in:

warm engine, WOT, cyl. 1,2,3,4 respectively.
185.180.125.175

after adding a cap of oil to each cylinder.
225.210.165.200

I am thinking valves on cyl. 3 are hosed?
Keep in mind I only want this to be a reliable stock car. Also, with the motor running, I can pull cyl. 3 wire and the car will barely stumble from its current running state, but the wire is definitely arcing to the valve cover.

 

well, valves have been adjusted, but the miss is still there.

I swapped injectors #3 and #2 to make sure that was not the reason, and I can still pull plug wire #3 without killing the motor, where as each other plug wire pulled will kill it.

Any ideas by looking at those compression #s? Rebuild top end, bottom end, or junkyard motor swap?

 

try replacing the piston rings on cylinder 3

 

Honestly, i'd just buy a d series swap. YOu can find non vtec's for under 300. A rebuild, done properly is gonna cost you more, but it'll be the most reliable in the long run. Theres a ton of options for swapping though, a z6 or a y8 will move that hatch nicely, and thanks to the light weight get great gas mileage.

 

Thanks for the ideas guys.

I want to keep this a stock car, so a different motor is out of the question.

Wouldnt the compression test on cyl. 3 be higher after the oil was put in if only the ring was shot? I have been leaning more towards valves.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LoudLude &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for the ideas guys.

I want to keep this a stock car, so a different motor is out of the question.

Wouldnt the compression test on cyl. 3 be higher after the oil was put in if only the ring was shot? I have been leaning more towards valves.</TD></TR></TABLE>

Bingo, do a leakdown test to make sure its vavles but I think your right.

 

cool, glad to see someone seconding the idea. It sucks, but I would rather rebuild a top end than a bottom.

I have never done a leakdown test, should I buy the tools and do it myself or just leave it to the mechanics? Basically I dont understand how letting air seep out of a cylinder pinpoints rings or valves.

 

listen thats all very extreme what there saying .First take the cap off the dizzy check for oil or debis it happens all the time then if that does clear the problem make sure plugs are gaped right then if that does work replace the plug wire of the cylinder thats missfiring one of those three should work if not get back to me ill come up with more

 

thanks for the ideas pootsi, but the plug wires are brand new, and all resistances are within spec. Plugs are gapped. dist. cap is new, no oil or debris.

The cylinder that is misfiring has spark.


hmm... how often does a fuel rail clog?

 

wow........do u have an air compressor? if not u need one for a leak down test. 3 is deffinetly low

 

Swapping in another d motor, is basically keeping your car stock. There is not much to it at all. Do a leak down, or pull of the head and see what you got. I too agree that if it didn't go up with the oil, your looking at valve issues. If your fuel rail was clogged, it'd mess up more then just number three, plus i've never heard of it Your not using any coolant, or in all my cases of a headgasket, filling up your over flow are you? I'm still going with my original post of valves are all gunked up, my buddies valves looked horrible when he bought his car. Good luck !!

 

Well, until I can get it into a shop for a true leakdown test, I did a makeshift test...

I just pressurized each cylinder at TDC. Results go like this:

Cyl.1: Blows air through the oil passages.. filler hole and dipstick hole
Cyl2: Tight. yay.
Cyl3: Blows air through spark plug holes and exhaust
Cyl4: Blows air through spark plug holes.

So now I am thinking headgasket as well. Which is strange, because the oil is not milky at all, and I have no coolant loss or white smoke. This thing has me pretty confused. Thoughts?

 

if cylinder 3 is blowing compression out the exhaust its the imfamous d series burnt exhaust valve and the head has to be taken off vacume tested and valves have to be replaced