I've been noticing this since some time after installing a high flow catalytic converter, I don't know if it's related or coincidental.

2002 Acura RSX, K20A3 (has dual runner intake manifold), 84K miles.

Under ~ 2K RPM, in gear and with load, there is a slight hesitation and lack of smoothness. I thought maybe it was my spark plugs again, so I replaced them with OEM spec NGKs, same part no. as per the shop manual. It seemed a little smoother for about a day, but now it seems the same as before the new plugs.

The engine smooths about above 2K RPM, and there is no other driveability issue.

Could this be a valve adjustment issue? I don't think it's a PCV problem. Maybe a vacuum leak?

These cars are notorious for dirty IACV problems (the IACV sits at the bottom of the throttle body and stuff just naturally falls into it), I clean mine out annually with TB cleaner. But a dirty IACV usually results in crazy idle fluctuation, not hesitation and roughness.

One other thing - I broke the IM bypass control solenoid nipple a long time ago when replacing a tiny inline filter and used superglue to patch it back together. It hasn't come apart, but it feels a little weak when I put mild pressure on it.

Anyone care to chime in on what the issue may be here? Thanks in advance!

Only engine code is intermittent P0420, which is caused by the high-flow converter. I've replaced both O2 sensors - I just need to add a defouler on the secondary sensor.

Thoughts:

. Clean IACV, IACV hoses, ports, throttle plate, and throttle body.

. Replace PCV Valve and clean hose with brake cleaner.

. Replace fuel filter.

. Check vacuum hoses and intake manifold for leaks.

. Ensure coils are fine. Did you coat porcelein and main electrode with dielectric grease? Attenuated spark on a 4-cylinder engine is noticeable.

You're a smart guy and I doubt, from afar, that I can "nail" the solution for you. Just go over everything.

Thanks for the suggestions.

I plan on doing all of #1.

#2 I have been postponing because I think I will have to at least partially remove the IM to get a wrench on the PCV. Grr!

Fuel filter! Really? It consists of a screen on the fuel pump, inside the gas tank. There is an access hole under the back seat, but I've heard they rarely need replacing. Of course, anything can happen.

When I pulled the IM to replace my starter a couple years ago, I reused the original rubber seals for the ports to each cylinder, even though the shop manual said to replace them.

Coils are almost new, I bought them from a salvager with ~ 11K miles on them after my originals were soaked in oil. Only thing I see with them is some rust on the outside, from being in contact with lightly rusted spark plug tubes.

Two of the plugs (and their corresponding coils) had white chalky stuff (almost like a salty substance) on them when I replaced the plugs last weekend. The other two did not. I don't know what the cause of that stuff developing is/was.

No, I didn't use dielectric this time - I did on the last set of plugs and they were the ones in use when the issue developed.

I just checked - the filter is part of the fuel pump assembly, can't be purchased separately!

New from dealer, pump costs ~ $250!

Interestingly, although Honda/Acura parts sites don't list this part, I found this on eBay. Wonder if it's any good:

2002 - 2004 ACURA RSX FUEL FILTER NEW OEM:eBay Motors (item 130303113202 end time May-27-09 21:20:24 PDT)

It's likely the real deal, if the part no. checks out.


I changed the fuel filter, after 25,000 miles, on my Taurus this morning.

Quote:

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Originally Posted by TxGreaseMonkey

It's likely the real deal, if the part no. checks out.

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I punched the part no. into an online Honda parts catalog - nothing came up.

I asked the seller about it, I haven't heard back yet.

Quote:

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Originally Posted by TxGreaseMonkey

I changed the fuel filter, after 25,000 miles, on my Taurus this morning.

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25,000 - or 250,000?

I change it every 25,000 miles. Ford recommends replacement every 30,000 miles.

Well, then, it's really odd that Honda/Acura has no replacement interval for the fuel filter - or the PCV valve - on this car/engine...

I always thought that was odd.

Guys on the RSX forums say the fuel filter should be good for the life of the car!

Many makers say replace platinum plugs every 100,000 miles. In most cases, they NEED to be replaced at 50,000 miles or less.

Leaving a PCV Valve in too long is a good way to prematurely wear out an engine. On my Civic, Honda recommends replacing it every 24 months or 60,000 miles, whichever comes first. For the fuel filter, Honda recommends replacing it every 48 months or 60,000 miles, whichever comes first. Lack of regular preventive maintenance is often a marketing ploy, since most people don't want to be bothered.

Well, it seems like there are plenty of recommended service intervals for this car, just a few odd omissions.

Like the PCV and fuel filter.

As I just finished asking on another forum - why is there no ordinary in-line fuel filter for this car, like there is on most cars? Are we supposed to buy ultra-clean, pre-filtered fuel from the stealerships?

Furthermore, the fuel filter I posted the link to is usually described as a strainer, as if it only prevents large particles from entering the fuel supply.

Have you ever worked on a K20A3? (Base model RSX and '02-'05 Civic Si, though I'm sure other Honda engines are similar.)

The PCV valve is nearly impossible to get a wrench on. And the only fuel filter is located in the fuel tank!

Have you ever replaced an in-tank fuel filter that is the only fuel filter for the vehicle?

Oh, BTW, my iridium plugs (supposedly good for 100K) looked horrible at 50K or 60K, when curiosity finally (and luckily) finally got the best of me!

The most difficult PCV Valve to replace is on my 24 valve Duratec engine. I had to design and fabricate a tool, in order to replace it. The local dealer wanted $350 for the job, because they would have to remove the UIM and LIM. With my tool, I replaced it in 45 minutes. Not one of Ford's better ideas.

There's always a cost to pay, when working on performance engines.

:eek: $350 to replace a PCV valve?

Well, I'm not sure I have your talent, but where there's a will, there's a way...

A lot of these RSX guys have made custom oil catch-cans for their PCV systems.

Is this really as helpful as they claim? If oil getting into the intake system is such a problem, why don't manufacturers put a filter on the PCV system?

Dayuuuummmmmmm!!

PCV was almost a piece of cake after all!

Had to go to two stores to find one in stock. But removing it was not as bad as it looked like it would be.

Used a long, straight, slender screwdriver to remove the tube from the PCV, then I unclipped one electrical connector that was in the way. After that, I was able to slide my 17mm deep socket right on that sucker, and broke it loose!

Great. Did it help the situation? Be sure to remove the hose and clean it thoroughly. Also, clean the port going to the plenum.

At first it felt like it resolved the problem completely, but after driving around a bit, I'd say it resolved about 90% of the problem, LOL.

I ordered a PCV, washer, two clamps and the entire hose (it's only about 18" long) from a Honda dealer in AZ yesterday. So I think I'll replace it all again when those parts arrive.

Who knows - the OEM PCV may be better than the off-brand part I bought. And the hose will be new and clean.

BTW, the PCV itself had some gunk on it, on the outside. It looked pretty clean inside, as did the threads in the crankcase. The little ball still rattled around like it should, but the spring was probably ready for retirement and I'm sure there was crud build-up inside that I couldn't see.

That sounds quite successful.

Quote:

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Originally Posted by TxGreaseMonkey

That sounds quite successful.

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:p

Yes - thanks for your advice and encouragement!