I'm ba-a-ck! Told you I rarely get time for this. Thanks again for everyone's input. Quick question: does the ULEV designation "change" anything, as far as the so-far-advice goes? This Accord is a ULEV (has that sticker on the rear door window!). To TexasHonda, yes the other three cylinders have good compression and are within 10-20 pounds of each other. The only thing I've done since September is try to look into that cylinder with an inspection camera, but of course it was a millimeter too large to make it past the spark plug threads (in other words it was a useless effort). Sounded good, but...

I'd like to "see what's going on" by (maybe) taking off the head. Is that too drastic a next step? Must be a lot of work, yes? Anywhere to get real (shop manual) step-by-step for that if it comes to that? Thanks again y'all. I plan to get into it again this weekend. We'll see.

 

I agree it's time to remove head and examine valves/pistons/head.

When you ran leak-down test, were you not able to determine source of leakage? That much air leakage should be easy to trace. It has to go somewhere.

A good 98-02 Honda Shop Manual is available from automanualsource for $22. As near as I can tell only differences in SULEV are exhaust and use of A/F sensor rather than O2 sensor. Manual does not seem to have extensive mention of SULEV.

good luck

 

Thanks TH. I thought it was odd too that it was hard to tell where the air (pressure) was going. I know I could hear/feel just a little at the oil drain holes in the head and assumed "a little" is always going to get past even good/perfect piston rings. I plan to re-do the leak down and maybe have a helper this time crack the air open and shut while I jam my ear against the tail pipe, WOT the throttle, and so forth. Thanks for the manual source. I hate spending money on a manual that says "remove old ____, install new ____" as if that wasn't obvious. We all need the tricks of the trade so to speak. Seeya!

 

Okay, here's what I learned today. One, I evidently did something wrong on the first leakdown test. To make a long story short (shorter) today I removed the entire cam follower assembly and ran a leak down test on all four cylinders. All held 80-90 PSI of air as long as I wanted to leave the air "on". Of course there was some "leakage" past the rings. The rate of leakage was consistent in all four cylinders. Having the whole follower assembly off means all valves on all cylinders are closed, period! Yes?

Before I did this I had my son crank the engine over with a rachet on the crank center bolt. CCW. I was watching at that time for something unusual, or different, at the third cylinder rockers, then assuming a valve may have been stuck open or whatever. BEFORE that I turned the engine (rachet on crank bolt) with a 3 foot steel brake line down the #3 cylinder spark plug hole, and watched it ride up-n-down on the piston.

Okay, so I figure my next step is to start her up again (gotta get a battery) and read codes. Sound like the right thing friends? Thanks again!!

 

Set the valve clearances before you fire it up.

 

You may have a misunderstanding of leak-down test. Leak-down test measures (relatively) how much air is bypassing all leak sources. It does this by supplying a regulated air pressure to an orifice and measures pressure on the lower side of the orifice. So if you supply 100 psi regulated pressure to the orifice and downstream pressure is 80 psi, the loss is (100-80)/100 or 20%. Was this what you did?

See following link for video on procedure.
good luck

 

TH, thanks for the lesson. I was simply applying air pressure to each cylinder and seeing if it held (with all the valves closed since the follower assemblies were "gone"). So officially that isn't a leak down. I'll do a real leak down next. Roader, will I (definitely) need to adjust since all I did was lift the assembly straight up then drop it back down? Thanks all!

 

Okay, fired her up today and she started right up, but ran pretty rough. DTC P1399 was the only code. Erased it and it came back. Ran better right at start up (because cold??) and after maybe a minute or two (tops) began surging/revving at idle. Drove her up and down the driveway a bit, but hesitant to take out on the street. What are my next steps? I'm heading back out to do real leak down test, based on TH's video. Thanks y'all!

 

P1399 is apparently an undocumented code that occurs w/ misfire. Did you get any misfire codes?

Leak down test seems logical.

If engine is running rough and no misfire codes, something may be wrong w/ ECM.

good luck

 

Hi ya TH. I did the leak down test (the right way this time thanks to you!), and here's what happened. The details: I removed all the plugs, set the gauge to 70 PSI and attached the quick-connect to the hose screwed into the cylinder. The gauge dropped to 64-65 PSI and held there. Rather than cranking the engine to TDC for each cylinder test, I removed the follower assembly again (assuming this would "simulate" TDC with all valves closed). The result (70 drop to 64-65) was identical in all four cylinders. The plugs I think are giving me a clue though. Plugs 4, 2, and 1 were "sooty" from the few minutes running earlier. Plug 3 is shiny clean with no soot/carbon. Can I assume there is no fuel getting into cylinder 3 perhaps? These plugs are brand new BTW, as they were the first thing I tried a lo-o-ong time ago. Whatcha think?