92 Civic VX stumbling/hesitation

[bowtieguy]

i believe that PCV is placed like the dx and lx models...under the throttle body, near the oil filter, and very difficult to get to. i replaced mine(lx) while the iacv was out to be cleaned. makes it a little easier to get to.

[add|ct]

Yes, prolonged use of any solvent-type cleanser may adversley affect rubbers over time.

The key is to change your oil after using the top-end cleaner, for that product type OR to change your oil in short order(1,000 change w/ filter OR 2,500; for example, and include an oil filter change at 1,500 for example basic oil filter not-super efficient during cleansing).

Use of the top-end you are on the right track. You do spray directly into the TB while the engine is running, have a friend or yourself keep the RPMs above 1,000 at least but try NOT to go above 1,500 if at all possible just prevent stalling. You DO want to shake the can so it looks like it's foaming as it comes out of the straw(make sure to have the straw 'seated' into the nozzle to avoid it going into the intake lol), so vigorous shaking before induction(this will feel like 5 minutes of constant spraying so be prepared for muscle ache, stretch b4 hand, the key is constant spray while shaking to make sure it's foam coming out until its empty or really close).

Yes, kill the engine(pull the map sensor if you are by yourself at the throttle body/plate to manually kill) as soon as the can empties or you just can't spray any longer. Close the hood, doing this with the engine at full temp during the day for max heat/chemical soaking, and wait 1.5-2 hours. Re-start with everything re-attached. Blip the idle 'marginally' if initially it wants to stall. Wait for about 5 minutes for the car to get to operating temp again, then SAFELY drive WOT without any traffic behind you. The key isn't speed, primarily, it's torque. Drive in 2nd/3rd most and push 1st initially to 30 MPH, hold 2nd at 50 or so. A few WOT runs, about 10 minutes of driving with varied stop 'n go driving heavy acceleration and return home to reinstall the 02 sensor. If you have your old one(assuming replaced before?) reinstall the old one just enough to not have a big exhaust leak. Or find something with the exact thread pitch/size to thread in to plug the hole for this temporary period of time.

Have you removed the valve cover to check the valve lash/clearance? Easy way to see if there is a lot of crud in valve-train area already, at least. Also, not much can generally be an indication that using cleaning chemicals with responsibility won't risk clogging a return passage or the oil pickup tube's screen, etc. I have not had issues with these processes, I used Power Foam before I got my replacement 02 sensor and have the original lying around if you need it just pay shipping.

[add|ct]

Originally Posted by bowtieguy

i believe that PCV is placed like the dx and lx models...under the throttle body, near the oil filter, and very difficult to get to. i replaced mine(lx) while the iacv was out to be cleaned. makes it a little easier to get to.

^This(if cleaning the IACV), or while removing the oil filter during an oil change.

While no oil filter is in place, you can 'work' the PCV valve out of this breather chamber seen in the pic below(worth removing the chamber itself but I havent yet on my vehicle, been lazy lol). The hardest part after that is removing the tension spring to removal/replace the valve itself, just some angled pliers help with the angle(no pun). Reverse order and seat it securely into the breather chamber.

Pic of area:

http://img600.imageshack.us/img600/8220/1003557.jpg

Notice the oil filter and the black looking box just above/to the right? That is the breather chamber for the PCV system. The PCV seats into the chamber on the left-hand side of that box, accessible with the oil filter removed(here you see the 1 wire plug removed, this is for the oil pressure switch; the dummy light, that I was replacing because it had a small oil leak internally). There should be a 'hollow' elbow plugged into the IM seen between the runners for cylinders 3 and 4 from the top of the engine. That is the PCV valve location on 94 and 95 model VX, Civics etc, IIRC. Our model has the hollow elbow at that location, so some VX owners of our year are running with 2 PCV valves and some may not be aware for the valve at the breather chamber, the actual OE location for those year models.

[benfrogg]

Good advice from all-
It just so happens I have a youtube vid on cleaning the breather box. It shows the PCV valve in detail.
http://www.youtube.com/watch?v=7V-BBmsVmY4

Bruce, engine warm or cold is fine for the diagnostics. Warm would probably be slightly better as idle will have a chance of being most stable (and you can hear differences in idle better).

B

[bcfromfl]

Thank you all for the additional info, and for the pic, add/ct! I just came inside from checking things out with a flashlight -- holy cow, I can't identify ANYTHING from the top-side angle!

The online diagram I use from the Majestic Honda site just isn't clear enough for me to tell if I have one or two PCVs. It seems to say there are two, both for the same price, but it only shows the location of one. Just not clear. The other one is shown as an inset diagram. How high is the confidence that they can be cleaned thoroughly, vs. buying new?

Add/ct -- you asked about the valve clearances. I had them adjusted a couple months back, I think at the same time as the O2. Little did I realize back then that I was just getting started...

Thanks for the detailed steps on the cleaning. I've babied this car so much, when I read your recommendations with WOT, I cringed a little. 200,000 miles, and all that! Years ago I had a high-performance Mitsu Starion with competition parts, and I drove that way, but not with this little sweetheart! (I'll give you a nice bath and wax job afterwards, OK?)

Ben, I just watched your video. Wow, just wow. Nice to have a lift so you can get at stuff underneath! ;-) Now we've brought the breather box into the discussion. How important is this? (I note that Majestic wants $41.25 for a new one.) Did you do this primarily as a concern that crud would get sucked back into the PCV? Do you think the crud inside the box is free-floating, or is it more of an oily crud that has adhered to the sides?

I must admit that I'm getting a little overwhelmed at this point. So many different ways to go with this! I'll start with the EGR diagnosis, I guess.

Thanks a million!

-Bruce

[add|ct]

Bruce, the breather chamber is like a bolted-on catch-can, it traps a lot of the vapor portion of the crankcase emissions(ventilation system). If the PCV valve is in a non-operational state or 'failed' state for too long, the vapors and byproducts of combustion will begin to oxidize faster and lead to a gummed up PCV system. This may lead to more carbon deposits in the piston head area, valve-train gunk. Long-term with extended Oil Change Intervals can lead to sludge in extreme cases + bad driving conditions(short trips, cold temps, excessive idling and stop 'n go driving as well as prolonged racing, driving a few times at the drag strip for 1/4 mile times is NOT racing and healthy on occasion for your engine in fact, similar to downshifting and using engine braking helping the ring land areas to true up if they have some imperfections).

For 1992-1993 VX models, I have a Canadian built/Canadian VIN, BTW, well it seems the FACTORY PCV valve is in the breather chamber and ONLY a 'hollow' elbow is mounted at the Intake Manifold itself(behind the valve cover, in between the 'runner tubes' for the driver-side 2 cylinders. Notice about 0:42 into ben's video[which is what I also will be doing for my breather chamber], no need to buy new unless your box is visibly cracked or damaged, just replace the o-ring on that big orifice that mounts to the block to prevent a small vacuum leak from developing and to ensure proper functioning PCV system).

Anyway, you should not have 2 valves. Honda part(s) sites like Majestic, etc. will show parts for 92-95 model VX when you specify your car.

I'd 'hope' the dealer has the original style, but both a straight and elbow 'dealer' seem to be offered, though 'apparently' neither one at the box. I'd imagine the straight style that is still available(picture as though it'd be in the IM location) may work at the breather chamber. Either way, delete one or the other, if you are running 2 valves and consider getting a elbow at the breather chamber if you move to a PCV valve at the IM location itself.

As for cleaning(top-end, ben's vid for breather chamber cleaning is a good idea), again it's suggestion. I've done that for my VX. It has other issues. Oil consumption is at 1 quart every 3,000 miles or so. I had the clutch replaced recently with an EXEDY OE style and I resurfaced the flywheel(original) + replaced the rear main seal while the clutch housing was open/flywheel was removed.

The VX transmission can take 1st gear up to around 35 MPH(its either 34 or 36 exactly cant recall), so driving 1st up to 25-30 to expel isn't an issue. WOT alone isn't an issue, running to redline 'may' be if your car is about to break anyway. What is your current oil consumption like? The key to using those top-end cleaners is to expell with torque/high revving with a load only for like 3 or 4 'drag strip like' runs of WOT. Just get up on it between 3,000-5,000 RPM from a stop; shifting where necessary, just enough until you don't see smoke from the rear. This will encourage any carbon deposits or other loosened up crud to be expelled(the reason for removing the 02 sensor).

Change your oil after. I went from using high-mileage oil(about 10,000 miles during first year of ownership), to full synthetic 0w-30 oils at 5,000 mile intervals with a goal to settle between 7,500-10,000 with UOAs to back it up. I've gotten a few Used Oil Analysis performed on my car, things look good. I have a drop-in K&N air filter that I now regret buying, so FWIW don't buy those, lol.

[bcfromfl]

OK, so I just performed the first of the EGR tests. The engine stalled quickly after I pushed the diaphragm up. I didn't do the vacuum test, for a couple of reasons. I wasn't sure about the condition of the hose (although it looks OK), and I figured I needed a better backup plan with a replacement hose. Maybe even hook up a longer hose so I could do the test more comfortably. However, I think it's a safe assumption that the EGR is probably in good shape.

While I was warming the engine up, something unusual happened. I did a 5-2 upshift into a left-hand corner, and as I goosed the accelerator to match RPMs, I got a single cackle/knock from the engine. It's never done that before, and almost sounds like a timing issue to me (although the timing was checked). Could this also be an air/fuel symptom as well?

I've been trying to construct a logical flow chart to attack this, and was thinking that the power foam thing would be a good precursor to try before dismantling or otherwise swapping out the IM, but now I'm wondering if this is the right direction. The power foam probably won't hurt, but I guess I need more convincing that I'm dealing with a crud buildup issue.

Next I suppose is removing the EGR to inspect, but I need to get out the tools and make sure I can do it first with what I've got, based on Ben's caution. Also should pick up some gasket sealant so I can recycle the old one. I'm going away for the weekend, so I may not be able to get to this for a few days.

-Bruce

[bcfromfl]

Forgot to reply to all your helpful comments, add/ct. Thanks for the additional info!

My car doesn't burn any oil. I use either 5w30 Mobil 1 or Castol Syntech, and change...dunno...given my driving habits with this car, once a year.

I remember buying a K&N filter for my dad's '84 Supra, twenty-five years ago, and he hated it after it got dirty!

-Bruce

[add|ct]

^Might need more info and attempts to 'repeat' the symptom you had earlier.

Oh, and I just mentioned the K&N b/c I don't like it passing more dirt into the oil which can lead to more wear. I'm deciding on going paper or investing in a Pro Dry S by aFe.

So, no consumption? Any oil leaks visible anywhere on the block? Vtec solenoid or housing gaskets? Do you monitor the oil level at all between changes?

When you say 5-2 upshift, what do you mean? Dropping(downshifted) from 5th into 2nd while entering a left-hand turn/corner? What was the MPH at the time? Did it pop while in neutral or after you engaged 2nd and the engine/transmission caught each other?

Good idea to check the timing. You can pull the valve cover gasket and then safely remove the upper timing belt cover to inspect the belt condition. Make sure one side has plenty of tension(usually means a good tensioner) and that one side of the belt doesn't have more tension than the other. Some slack on the water-pump side is normal, the side with the belt straight down needs to be solid. You could always use a timing light and check the timing. IIRC, the VX needs to be at either 16 or 18 degrees (before?) TDC. The manual linked spells this out. Will look myself and report back later.

Also, as long as you change your oil afterward and don't risk fouling your 'new' 02 sensor, I see no harm in a top-end cleaning. Also, I've done a top-end cleaning(drive to expel) THEN followed immediately with an idle 'flush' for 15 minutes before dropping the oil. This gives the best 1-2 punch for a 'mild-moderate' clean attempt. As long as you have no actual sludge, we're only talking deposits and some mild slimy grime, etc, then you aren't risking anyway. Bathing the engine in plain solvent and soaking or prolonged engine OCIs might lead to gasket failure, using a High Mileage oil for a year or 15,000 miles; for instance, is a good step for any older vehicle. If on full synthetic already, Mobil1 High Mileage 5w-30 is a great 'full synthetic' HM oil, I also like MaxLife full synthetic from Valvoline(have used their red bottled blend with some success regarding leaks before).

If you did that top-end cleaning, run a full tank down to near empty with something like Red Line SI-1 Fuel System Cleaner; prior to the other, for a complete 1-2-3 area attack at different locations for contaminant 'settling'. I've done Power Foam twice on the VX, idle flushes at least 3 times, and fuel system cleaners with PEA about 3 times since owning just before 2010 started.

Get the timing checked if you are concerned. You can also try cleaning/replacing or adding more grounding wires. I cleaned mine, haven't cleaned the fuel injector ground, yet though.

[bcfromfl]

Hi again, add/ct! Thanks so much for your continued help!

The engine was fully hot, and I was driving maybe about 43 or so in 5th. I shifted into 2nd, then goosed the accelerator just before releasing the clutch. (I don't double-clutch.) It cackled once, as I gave it gas in neutral to match RPMs. The timing was just checked within a couple of months, as I'm getting close to the timing belt/water pump replacement, and the mechanic wanted to eliminate this possibility. I can't remember exactly, but I'm around 50,000 miles since the last one.

Another thing I noticed as I was warming up the engine. I'm paranoid about the tachometer since the issue with the ignitor, and know now that the tach is a good indicator. But as I was accelerating at that spot about five miles from our home, where before with the old ignitor it would stall (and give a Code 15), I got a pause then "jump" with the tach maybe around 50mph in 2nd, from ~3k to 5k. This was such a brief, unexpected thing, I'm not totally sure, but I think there was a slight accompanying pause from the engine. Certainly not a huge hesitation like the tach seemed to indicate. I know the tach is electronic and not like the direct link cars of old, but the tach normally operates smoothly without blips. When the engine was fully warmed up, no blip could be replicated after this point.

This seems to be telling me, again, that there seems to be an electrical problem and/or sensor issue, that's somehow temperature related. Perhaps there's two things wrong, and the symptoms from both issues are confusing the diagnosis!

From your description of your VX, it sounds like it was really, really messed up with crud. I can't imagine how an engine would get that way. I have no oil leaks, save for perhaps a small one around the oil pan gasket. Not enough to drip yet. I check the oil level a couple times between changes, but there's absolutely no consumption.

This is really discouraging. Seems like there's just no easy answer...

-Bruce