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Love the videos on youtube, great stuff…
A little on the car… 156k miles, only modification is a K&N drop in, which has been in there since 55k, cleaned yearly.
One day coming home from work, about 6 weeks ago, the check engine light came on in my car. Went to advanced auto parts, 5 codes, misfire in each cylinder and a random misfire code.
Did some googling, this is what I’ve done so far:
cap
rotor
spark plug wires (OEM acura)
NGK platinum (made in Japan, not the german)
fuel filter (oem acura)
cleaned IACV/FICV
new PCV valve
checked for vacuum leaks using ETCG video method.
ear to the screwdriver, all injectors clicking
bottle of techron
checked ecu connectors, compressed air and cleaned inside and out.
distributor o-ring (no oil leak inside but a very small one outside)I didn’t do it all at one time but after basically each thing I changed something, i disconnected the battery to reset the ecu.
Between each part change, the car showed the following symptoms:
Rough idle when cold (if you look at the exhaust, you can see it kind of skip every once in a while)
backfire while going up a steep hill, if 50% or so throttle is applied.
flashing check engine lightso flash forward to TODAY and how it runs:
exhaust still skips a beat every once in a while
no more backfire, no matter how hard I trynew symptom: the cat is rattling like crazy inside. So it’s blown.
These are my questions:
is there any chance the cat clog up and caused these symptoms, then finally gave up? Or is it more likely, according to what I described, that something upstream, ruined the cat?
Is it possible for the car to throw multiple cylinder misfires, but only actually be one cylinder? The reason I ask this question is, some say it could be valve/headgasket compression issues. If it was a burnt valve or cylinder issue, why would it say every cylinder is misfiring?Thanks in advance!
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btw took it to an acura dealer about 2 weeks ago, they couldn’t find anything at all. They did say i needed to buy new tires, new wipers, new oil pan gasket (i already knew all of that, declined all). Reset the ecu and sent me on my way.
Backfired/misfired as soon as I left the parking lot. Went back, demanded my money and am fixing it myself. Had to buy a bunch of tools (never worked on cars before) but I don’t trust them.
Well done on using OE parts. You get a gold star for that.
As for the problem it sounds like it could be your valves. I’d adjust them and see what you have.
If that doesn’t work you might want to do a leak down check as you could have a burned exhaust valve. This can cause a misfire.
Leak down testing
Finding TDC
Also, if a timing belt was done recently then check the wire going to the crank sensor. Sometimes it’s not secured properly when doing a timing belt replacement and as a result the alternator belt can cut through the wire going to it.
I don’t think your catalytic converter is bad. It’s more likely that the shield on the outside is what’s making the noise.
Catalytic converter diagnosis
Restricted exhaust
Exhaust rattles
Keep us posted on what you find.
Thank you for the replies, I am very grateful.
college man, I did the vacuum leak test, sprayed down pretty much everything, no changes in idle. power balance test, I haven’t done because the misfire is so intermittent. It’s sooooo smooth then all of a sudden, it will skip one.
I agree the plugs look awfully white, I definately have fuel pressure. I did order a fuel pressure gauge to put on so I’ll be checking that according with and without vacuum (helms procedure) to see if the pump and fuel pressure are within spec.
EricTheCarGuy,
I’m going to do the valve adjustment first thing sat. morning. It was last done at 90k miles, upon my request, when it had it’s timing belt/water pump, belts, ect ect done (not by me). 60k miles, 4 years later, it may be probably due.Going to watch the other videos tonight, fingers crossed the cat isn’t bad! Thank ya’ll again for the help!
Update:
Wenesday, after 2 months of fooling with the car, with no other new changes, the CEL went off. Haven’t heard the car backfire, staring at the exhaust pipe, every pulse is as it should be. Car runs super smooth, 100% full throttle up hills, no problems.
:blink:
Went ahead and installed the fuel pressure gauge anyways.
Factory spec, w/o vacuum line attached
40-47 psi, gauge, 44 psi (fuel pump good)Factory spec, w/ vacuum line attached
36-43 psi, gauge, 35 psi (fuel pressure regulator… hmm)My guess, the fuel filter was really bad, lots of sand, the fuel that came out the dirty end was almost black. I’m thinking the fuel system was in really bad shape and it needed a clean filter and a few tanks of clean fuel to go through to get the pressure back up to spec and was running lean due to lack of fuel pressure before.
What do ya’ll gentleman think? I haven’t done the valve lash yet, valves sound normal but will try if the misfires come back, if not, will just have it done at next timing belt service. As for the rattle, I don’t have a jack/stands, so I need to wait till have access but I think you’re right Eric, it’s very likely to be the shields, otherwise, I’d be throwing codes, having performance issues.
seems to be solved.I hope none of that dirt
made it past the filter and into the injectors.
if the issue comes back.I would remove the injectors
and clean them out with carb spray.I was just about to post!
The problem came back. Drove perfect for 2 weeks.
Came outside of work (nothing odd happened during the day, wasn’t really cold, didn’t rain).
Fired up the car and the idle was very rough. CEL came on, blinking non stop. Not a random miss but the engine shook at a very constant interval (so the problems seems to be at one cylinder).
If I was smart, I would have done the power balance test right then and there and figured it out, but I shut the car off. Fired it back up, problem is gone. Fuel pressure read within spec this time.
I do not have the codes but will go this weekend to have them pulled. May have to get those feeler gauges out and give that a go and clean the injectors/replace o-rings as well.
Oh, and to add to the list of parts changed weeks ago, ignition coil, non-oem.
Update: yesterday, came out of work, engine shakes, so did the power test.
Cylinder 3 was the only one that didn’t make a difference when I pulled out each spark plug wire (which are new as well as the spark plug).
Reset my ecu, since I figured the test may make it throw additional codes.
Today, drove and heard a backfire upon load/acceleration. Light came on immediately and I happened to be .5 mi from the auto parts store.
Codes:
P0706 Transmission code (google says park/neutral switch may be faulty, doesn’t seem like a huge deal at the moment)
P1399 random misfire
Also 3 individual cylinder misfires (2, 3, 4)Valve lash then injector cleaning is next on my list but I’m going to wait till I visit my folks in a few weeks to do them, since I’ll have an extra car to go get parts if I need to.
the random misfires.Are the plugs NGK?
also the wires.if there the OE leave them.
if not use NGK. all your ignition parts should
be OE not aftermarket.Honda ignitions are picky
and run best with OE.Plugs are NGK
New wires are OE
new Cap/rotor/coil are aftermarketI’d buy a new $800 or whatever oe distributor if I knew for sure it was the problem for sure but if I’m just throwing parts at it, it’s hard to justify.
i’m tempted to buy an obdii scanner/software.
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