Pinging under partial throttle

[Vanilla Sky]

Alright, this one is stumping me. I have replaced the following within the past 3,000 miles: fuel pump, fuel tank sock, fuel filter, spark plugs. Within the past 2 weeks, I've replaced the spark plug wires (ripped an end off), changed to a colder spark plug and tried with both a larger and smaller gap, change the fuel filter again, and flushed my cooling system. I haven't checked my tank sock since I put it back in, but crud is getting through it. I think I need to either seal or replace my tank. In the short term, I'd like to get this fixed.

What other things can you guys think of that I'm not checking? TPS, o2 sensors? Temp sensors? I've always had carbed cars and I just ripped the emissions junk off and never had an issue. I'm not to the point I can megasquirt this one yet.

[Keachman1]

Check your ignition timing and vacuum advance to make sure it is not sticking. Too lean of an air-fuel ratio will cause pinging also so check for issues that cause a lean mixture like plugged injectors, vacuum leak, low fuel pressure, O2 sensor, etc. Carbon buildup in the combustion chambers can also a cause it along with too high coolant temp.

[2oodoor]

Good suggestions. The distributor advance plate rests on a ball bearing set that covers the circumference of the dist body, which is the coolest design but it can get gummy and stick after 25 years.

[Legend_master]

I'm not sure about obd0, but on obd1 an improper coolant temp signal can cause a lean issue.

[Vanilla Sky]

Ignition is as far retarded as possible. Vacuum advance works when I cap off the port on the vacuum manifold and pull vac with a mityvac. I'm inclined to install a different distributor since I have one laying around.

[Stealth]

.

[Dr_Snooz]

How many miles on the engine?

[Vanilla Sky]

215,000 on the odometer, looks original to me. I'm not above pulling the head because I have a half built ported head I can finish up and bolt on if it turns out that mine needs to come off for any reason.

Spark plug color reads normal. No oil leakdown, no signs of more carbon ash than to be expected, and they're completely dry. Of course I'm not doing a hot pull here, but that sounds like what I should expect from my spark plugs.

[Vanilla Sky]

So, it pings less in the cold. Seems temperature sensor related somewhere maybe. Has anyone ever have an intake air temp sensor go bad?

[2oodoor]

Sometimes what pinging is tellng you there is something in the compression chamber at a time when there isn't supposed to be. Carbon, coolant, exhaust charge or intake charge, water in fuel, something like that.
That is why the ign timing relates to ping, timed explosion not clear of charges, solids etc.

[cygnus x-1]

These engines are fairly knock resistant so something is definitely wrong. What is your ignition timing advance at idle? Shouldn't be anymore than about 20 degrees. If you have a dial back timing light you can also check it at say 2500RPM and see if it's advancing too much (no more than 35 degrees). If the mechanical advance mechanism is sloppy it could be advancing too much as the RPMs climb. Sticky vacuum advance is another possibility.

And then you could possibly have gotten a bad batch of fuel as well.

C|

[Dr_Snooz]

You sure your timing belt didn't jump time?

[Vanilla Sky]

Tomorrow, I'm going to recheck the timing belt and recheck the timing. The ignition timing is set as far retarded as it can go, so if that's my cause, it's because it's worn out. My next step is pulling the fuel pump and checking that sock. I can see into the tank then, so if it's nasty, it might come out for cleaning and possibly sealing if I find rust in there. The fuel filter was gunked up pretty bad, so I was sure that would at least tell me that a fuel system cleaning would solve the issue.

Would the valves needing adjustment cause ping? I adjusted them a while back, but I'm not terribly sure I got all of the retainers tight again.

[Dr_Snooz]

Usually you'll just get a lot of noise. I've had them pretty loose and didn't get any pinging.

[88Accord-DX]

I'd hook up a timing light pointed at the mark on the flexplate/flywheel & see if your timing is good.

[Vanilla Sky]

I need to find some time to work on the thing.

[Vanilla Sky]

Threw a code today, but turned the car off and cleared it. I've gotten one before under similar conditions (same bit of road, even) that was for the EGR lift sensor. I haven't had any codes for weeks, so I didn't mention it in this thread.

Somehow I think this could be something other than pinging. I haven't had it on a lift to check for anything loose, but it is a thought.

[Legend_master]

Have you checked the condition of the EGR? Technically it could cause some pinging?

[Vanilla Sky]

I have not. The guys that have theirs blocked off seem to have no issues, but I remember it being a huge deal with small block Chevies from the emissions era. Time to pull and check it out. I've been meaning to check it out anyway. So little time, so much to do.

[Keachman1]

The EGR valve sticking open will cause your air-fuel mix to lean out and could cause pinging. Try a block off plate and see if it helps. You will probably get a code but you can always re-install it if it cures the pinging and your location requires smog. Cleaning the EGR valve with carb cleaner works sometimes.

[Vanilla Sky]

Nah, no smog here. If I weren't having running issues right now, I'd likely be working on installing a megasquirt system so I can tune the thing right. I want to put an OEM air box and piping back on and possibly a stock muffler (my only 2 real mods) and dyno tune it compared to the same car on the stock EFI. They probably left a lot of the table with these engines because the tech wasn't available then like it is now. The more sensors and monitors you have on an engine, the closer you can run it at the edge of blowing up, or the longer you can make it last. Since I'm not in this to be a number matching, show-quality car (it already has a transmission from another car), I plan on playing with it, perhaps coming up with some fixes that Honda should have implemented from the beginning.

[w261w261]

Try filling up with 93 octance and see if it helps. Also, you can get one of those video inspection tools and stick it into the combustion chamber and see if there are deposits.

[Vanilla Sky]

Last fill was with 93. No change there.

My EGR valve does leak down after a few seconds, but I haven't had a chance to replace it. I think I'm introducing unmetered air somewhere. I'm thinking it might possibly be my fast idle valve, because it tends to car the bouncing rev (blocking the port in the TB with my finger levels off the idle to 800RPM, so that's an air leak, and at partial throttle, there might be enough air passing through there that i'm running lean. This also explains why I don't hear it pinging at full throttle, because it's just dumping fuel at that point, and the throttle is full open, keeping air from passing through fast idle valve.

I think I might go take a video real quick and post it up for you guys. Maybe you'll hear something I won't.

[Dr_Snooz]

The O2 sensor should be richening it up so you don't ping. That's its job. Unless you have something else going on, a vacuum leak shouldn't give you pinging.

[Legend_master]

Just a quick thought, what about the fuel pressure regulator? If its not working properly your fuel may be leaning out.

[Vanilla Sky]

I could switch out the FPR, that's easy enough, as I have a few that came off of running cars.

It could simply be my O2 sensors going bad. They look new-ish, but I let the car sit up for a long time before I started driving it. Any number of sensors that were a little dirty when it was parked could be really nasty now. I really need to spend the afternoon with my meter going over every sensor.

[Vanilla Sky]

Did some work today. I figured out how to rebuild the fast idle valve, and there will be a how to video coming as soon as I can get to the junkyard for cores.

In doing some exploratory work, I pulled the throttle body. The entire inside of the intake is black. The air ports on the throttle body are plugged up. I have a new TB I'm putting in because it has a known good TPS, just to eliminate that and reduce cleaning time since I've been working on it since 9AM again. Lots of problems fixed, but that fuggin' ping is still there.

[Vanilla Sky]

Well, I think somewhere along the road I sold that spare throttle body. I can't raid my last car for parts because it's gonna be a rallycrosser.

What I hate is that I've been working either on my car or this website at least 10 hours a day 3 times a week for several weeks now. There's going to be a ton of cool stuff coming from this way.

[Vanilla Sky]

Took the upper intake manifold and the butterflies out. The butterflies were covered in more deposits than the throttle plate. It will all be clean when it goes back together, but it looks like that will be tomorrow.

Don't you love 5 minute projects?

[Legend_master]

Dude you should put it all together, and seafoam that thing. Sounds like your biggest problem may be carbon build up.

[Vanilla Sky]

Got the top half of the manifold and the butterflies factory clean. I cleaned the idle air control valve and rebuilt my fast idle valve. My idle is rock solid at 800 RPM now. The ping, however, is worse. This is seeming more and more like a lack of fuel pressure. I have more air going in, now I'm pinging harder.

My other question is whether or not the butterflies being open when they aren't supposed to be cause my issue? Symptoms line up. I ping from 3000 through 5500 RPM, which is when I recall the butterflies are supposed to open and likely get an extra dose of fuel.

The other direction to take this is a worn distributor. I think I'm going to do Snooz's lazyman's rebuild on one and install that. The one on there looks to be OEM at 215,000 miles.

[Vanilla Sky]

For what it's worth, the FSM states that you need to make sure all sensors and valves be in working order before troubleshooting any further. That's why I spent so long getting everything clean today. I'm going to work through testing sensors and reporting back.

[cygnus x-1]

IDK man, I've tuned my MS lean enough to where it would misfire badly, but it would NEVER ping. Unless you have really bad fuel I don't think fueling is the problem. Heavy carbon buildup is a very real possibility because it not only creates hot spots in the cylinders that can pre-ignite the mixture, but it also can take up enough volume to increase the compression ratio which increases the likelihood of pre-ignition and detonation. Seeing how your intake was badly plugged up I would say a Seafoam treatment is in order.

The fact that your distributor is retarded as far as it can go is also highly suspect. Even before Seafoaming I would at least check the timing at idle to make sure it's not completely off in left field. And even without a timing light you can check the cam timing by lining up the flywheel at TDC and looking at the marks on the cam pulley. They should line up with the top surface of the head.


C|

[Vanilla Sky]

Since I'm trying to learn more about what's causing this ping, I'm not doing any more treatments. I want to figure out what it takes to make these run like this, so we know how to fix it next time.

One thing I'm thinking is that the last time I did a valve adjustment, it might have ended up too tight. I think that correlates with when it started getting more prone to pinging. I think I'm gonna check them tomorrow. Pulling these heads off is pretty easy, so I might give it a new head gasket and check things out.

[Oldblueaccord]

2nd runner butterflys only open after 5500 rpm as i remember.

[2oodoor]

Ive heard a very faint sound before that kind of sounded like ping but it was something else because ping usually happens only under a load. I honestly thing it is something else that is hitting the same sound frequency. A valve tappet could do that and not even be out of adjustment, or any one of the accessory pulleys or even alternator.
I don't know how loud your sound is.
I still think what you're doing to find out is productive and beneficial because I could be wrong and nobody can afford to be wrong with preignition issues.
I'd put a good light on those rocker tappets when adjusting and make sure the feeler guage lays flat on the stem and not at an angle. Common mistake if you don't have 45 deg angled feeler guage.
If you pull the head, may as well triple check out those valve seats!:)

[Vanilla Sky]

If I pull the head, a freshly built ported head gets installed.

Update for this morning: Been doing some "Italian tune-ups" and the ping has softened a good deal. I did add some Marvel Mystery Oil to the tank (4 ounces to about 10 gallons of premium) and to the crankcase. I've had it work wonders in the crankcase for desludging an engine, but I've never tried it in the tank. I didn't expect it to work, but it may be what's slowly curing my ping. My guess is that it is cleaning out my cylinders, too. I was hoping it wouldn't work, to be honest.

Next thing I work on will be the distributor after I make all of my timing checks. I'll get this thing running right no matter what.

[Vanilla Sky]

Something is askew here.

http://img.photobucket.com/albums/v234/wannabe_otaku/IMG_20130224_123244_zpsfc76aee3.jpg

http://img.photobucket.com/albums/v234/wannabe_otaku/IMG_20130224_123323_zps65dd0c3e.jpg

Not a whole tooth, but it does look like I'm dealing with quite a bit of stretch here.

[Oldblueaccord]

Right side looks like its missing a chunk of belt.

[Vanilla Sky]

Nope, it's the lighting. Camera phone stuff here.

I set the ignition timing to spec and tested the vacuum advance mechanism. Everything checks out and is to spec. Pings worse now than it did before because I've now advanced the timing quite a few degrees. I'm going to look into a timing belt replacement as soon as finances allow it. I still think I'm shooting in the dark there, and I'm going to continue with more testing of sensors as time allows.

[g.frost]

Only time I had pinging was after many years of buying suspect gas at a local cheap filling station. Carbon build up in the cylinders and valve deposits had made it to run like crap. I was able to blow it all out with PEA (Redline SI-1) detergent, full bottle in a full tank and Italian tune up driving. (good and hot on the freeway and climbing a long grade in the Sierra's at full throttle) With that treatment it was fixed after one tank of gas, but really needs to get up, go, run hard and hot to burn up the deposits. That was many years ago and not a problem since....

I have since switched to only using top-tier gas and adding maintenance dose of SI-1 to the gas.

[Dr_Snooz]

Not a whole tooth,

It looks like a tooth to me. If you retard it a tooth, it might be enough to allow you to adjust out the rest at the distributor.

[Vanilla Sky]

Well, I'm going to pick up a timing belt anyway. If that one slipped, chances are it will happen again. Gives me a chance to install a front main and cam seal.

[cygnus x-1]

It looks like a tooth to me. If you retard it a tooth, it might be enough to allow you to adjust out the rest at the distributor.


:confused:

I'm not seeing it guys, that looks damn near perfect to me. Replacing the T-belt might be a good idea anyway if it's old, but if it was off a tooth either way it wouldn't even be close to the TDC mark. And seeing that your timing checked out ok with a light, I would go back to looking at carbon buildup. The only other ignition problem you could have is a mechanical problem with the distributor, like if one of the springs broke and the mechanical advance is coming in too early or too much.


C|

[Vanilla Sky]

Just installed my GE cam gear and verified 100% that my timing belt is now on correct. It was a tooth off. I put the GE gear on because I had it, not for any other reason. It is set at zero. I set the ignition timing again with my timing gun. Lots more power.

Still pings.

It did occur to me today that I haven't even had the cap off of this distributor. That leaves the condition of this distributor a complete mystery. I'm still thinking ignition, but now I'm thinking mechanical advance. I still don't think this engine is carboned up bad enough to make it ping like this.

Now, I did do a full throttle 3rd gear pull to redline today. I don't think it pings or makes any noises other than a little valve noise when I do this. I got no puffs of smoke from the tail pipe when I did it, and I was fully warmed up at the time. If I was going to burn carbon off as smoke, it would have been then. The lack of soot when doing this is why I don't think this is carbon related.

[89T]

By chance have you checked the oil pressure?

[Vanilla Sky]

I have not, but it sounds like ping, not a knock.

[2oodoor]

By chance have you checked the oil pressure?

^^^this is a good idea for anybody with these cars because those oil pumps have that internal rubber seal very much like the oil filter adapter seal, it is round stock rubber like o ring and can get a crack in it. This can randomly and intermittently affect oil pressure and you would never know it without a gauge on it.

[89T]

Low oil pressure will make all sorts of different noises.

[Vanilla Sky]

Very true. It doesn't help that our oil lights only light up at like 4 psi. I will check it when it stops raining.

[Dr_Snooz]

Vids of pinging please.

[Dr_Snooz]

:confused:

I'm not seeing it guys, that looks damn near perfect to me.

Looking at the photos again, I think you're right. On first glance, it looked like the cam marks were aligned, while the crank was slightly past. Having looked again, both marks are slightly past.

My bad.

[Vanilla Sky]

Snooz, when I aligned the pointer, it was a tooth off at the cam. I put my GE cam gear in because I needed to remove the stock one, and when I rechecked the ignition timing, I had to advance it quite a bit to get it back in spec.

I've tried to get videos several times, but I haven't been able to get a good sound recording of it. You can really only hear it when I have the window down, and the wind noise cancels out most other sounds. I am thinking about mounting a camera in the engine bay, I just have to find a place.

[Vanilla Sky]

So, I read over in Civic land somewhere, that they have EGR valve issues that cause exactly my symptoms. I'm also throwing that lift sensor code. You guys think the EGR is doing this? I mean, plenty of you guys just block it off with no ill effects.

My other worry is that my oil is thin. When I did my change, I used 10W30 instead of my usual diesel oil fill, which is 15W40. I'm going to give that a shot, too, to see if I clear anything up that way. I do know my oil looks pretty nasty and ready to be changed at just under 1,500 miles.

[dieselgus]

Hmmm. Interesting point. Generally extra EGR cycling will cause effects other than pinging though (running rich, hesitation, lack of power). The real trick thing to do would be to use a vacuum pump to manually cycle the EGR and see if it does it repeatedly. Secretly I am thinking something in ignition land like a slightly lazy advance mechanism.

Maybe it is the other way round, and you have some slight clogging in the EGR passage of the intake, and when the ECU calls for EGR there isn't enough going in there and it is causing adverse effects (it can happen.)

[Dr_Snooz]

EGR does cool the mix, so theoretically, it could be EGR. I've never heard of it, but I'm not omniscient either.

[cygnus x-1]

Lots of old GM V8s would ping if the EGR stopped working. The reason is because the ignition timing was advanced to compensate for the slower burn caused by the EGR. So without the EGR the faster burn would cause pinging unless the timing was backed off. I haven't heard of it happening with an A20 but that's not to say that it couldn't. Perhaps this combined with the heavy carbon deposits (and maybe worn distributor) is enough to make it ping.


C|

[Vanilla Sky]

Well, there was far far less pinging today. I had to try to make it ping. This may be the MMO that's still working its way through the tank and cleaning the deposits out. I need to take it out on the highway, but I really want to get it aligned first, and there are some things I need to replace before I have it aligned. Time to buy lifetime alignments?

[ecogabriel]

I had a lot of pinging when my EGR valve was defective. EGR flow is supposed to cool down ignition temperature and prevent pinging.
Once I got a working one from the jy the pinging stopped, and I passed emissions. Had no problems since. I should have a working EGR spare if you need one, but 4G EGR valves should work if you know how to wire them (the connector is different. I may need to do the experiment in my car (a 4G accord EGR valve in a 3G) and see how it goes

[Vanilla Sky]

I think I'll give the EGR valve a shot since I'm getting an EGR lift sensor code. I'll troubleshoot that system and see where it leads me.

Like I said, Civic guys have issues like pinging with a bad EGR valve. They have a rebuild procedure and everything.

[ecogabriel]

I think I'll give the EGR valve a shot since I'm getting an EGR lift sensor code. I'll troubleshoot that system and see where it leads me.

Like I said, Civic guys have issues like pinging with a bad EGR valve. They have a rebuild procedure and everything.

If you have a code 12 it may be an indication of the valve not opening enough (you said the valve did not keep vacuum). If you search the forums, I believe I posted how to test for the lift valve sensor with a vacuum pump and a multimeter. You may also want to test whether you have 7-8 inches of vacuum at the vacuum regulator (the green-white disc inside the infamous black box)

[Vanilla Sky]

My issue is that my vacuum pump leaks down. I need to replace it. I can't accurately test anything with the vacuum system until I do.

[Vanilla Sky]

And yeah, code 12. I'm sure I need to pull my lower manifold and properly clean the EGR passage.

Either that, or I can get a computer from a 3gee with no EGR, lol.

Edit: Well, I remembered that I don't have to remove the intake manifold to hit both ends of the EGR on these, but it might make it easier. I really don't mind getting it all nice and clean.

[Vanilla Sky]

Cleaned my EGR valve and tested it. That's working properly. My brother in law put $10 of regular unleaded in a near empty tank, and now it pings worse. I'm really thinking about another heat range colder on the spark plugs. Still within spec per manual. The last heat range colder seemed to help a good bit.

I wonder if it's possible that I'm developing hot spots due to coolant flow. I seem to get normal flow at the radiator, but I know everything is pretty crusty in there.

[2oodoor]

I think at this point I would a different set of injectors, probably pick some up at the yard off something that appeared to be taken care of. I'm not sure if you tried that yet or not.

[Vanilla Sky]

Yeah, I don't think that's a bad idea. I've thought about ordering a set, but I'll need bigger ones when I turbo it.

[Dr_Snooz]

I may need to do the experiment in my car (a 4G accord EGR valve in a 3G) and see how it goes

It would make a great How-To. 3g's are getting scarce in the yards so conversion instructions would be useful.

[Vanilla Sky]

So, I cleaned my fuel injectors. I have a pump setup that runs solvent through them and pulses them. No change. I need to set up a timer so they will pulse automatically and let them run for a while. It's something I'd need to do to a junkyard set anyway.

I really think this is something else. It seems to be able to supply the fuel at higher RPMs, so I don't think it's a supply issue, but I do think it could be a sensor issue. As soon as this GB passes, I can start spending money on this thing in earnest again.

[jbabb]

you may have worn part of the pcv system you said it got better with thicker oil (less blow by) lots of blow by gasses can get oil in the intake manifold causing a gunky manifold also would richen up the mixture.

[Vanilla Sky]

See, that's something that the service manual tells you to check before doing anything else. I haven't even tested mine, even though it's a quick test. It's a $2 part, as long as you don't need hoses.

[2oodoor]

you may have worn part of the pcv system you said it got better with thicker oil (less blow by) lots of blow by gasses can get oil in the intake manifold causing a gunky manifold also would richen up the mixture.
Valid theory, that makes a vicious cycle of crud since that would in turn clog up the vac port for the pcv.
The plugs should be spilling the beans on the chamber enviornment, if the preignition culprit doesn't evaporate it has to be a solid ash after combustion.
This is a great thread and every suggestion has been something that proactively affects the enviornment in the chamber and has caused ping in other cars.
If there is a cyl creating more heat , that should be detectable using an infrared thermometer.

[Vanilla Sky]

I said it got quieter with MMO treatment in the fuel tank and crankcase. It took about 20 minutes to help, making me believe it was a fueling issue with the MMO possibly giving more detonation resistance.

[Vanilla Sky]

For what it's worth, no CEL in a couple of days, so the EGR valve cleaning solved that issue.

[Vanilla Sky]

Alright, it pings a lot less now, but I am running 93 octane. Last premium fill was 91 octane.

Now, here's a question. I'm not pinging at all with the motor dead cold. No ping until the coolant is warm enough that the TW sensor tells the ECU to switch to the O2 sensors for fueling. Every time I've let a car sit for more than a year or so, it's needed a new O2 sensor to run correctly. I think the next thing I'm going to do is change those out. They can be tested with just a multimeter, but the process is annoying enough that I'd rather replace them. What do you guys think?

[Vanilla Sky]

Now I have another issue. Any time the car is in motion, it acts like I have a sticky throttle. When I come to a stop, it idles fine. I checked the throttle linkage, and it looks fine and I didn't see any obvious vacuum leaks, but this sounds like a fast idle valve issue, right?

[stuntjunkie199]

I had a similar problem a few months ago. The idle "hung" high until the wheels came to a stop. I thought it was in the he throttle linkage/ cable assembly but it turns out the IACV was defective. I cleaned it first, no change. Then I cut a piece of cardboard and blocked the air flow from it. Fixed the problem right away. You could test it like that in just a few minutes. Don't take completely off just loosen it up enough to get the cardboard in behind then tighten back down. I'd bet this will take care of it.

[niles]

Great writeup Vanilla.

I know it's been a while but did you figure this out? I am experiencing very similar issues right now and am early-on in the troubleshooting phase. I can't use regular gas or it's ping-city! I've gone full retard on my timing too.

[Jacques]

If you have a aluminum intake tube, like most do for a pod air filter, they can cause a harmonic that sounds like a ping. The sound is usually at over 3000 rpm. Just food for thought.

[Vanilla Sky]

I got it fixed, but I forget what fixed it. The motor blew in that car, so it's been parked for a little over a year now.

[Dr_Snooz]

I got it fixed, The motor blew

Oh! Great fix, VS! :rofl:

[Vanilla Sky]

Well, I haven't had a single idle problem out of it in over a year.

[niles]

I will add blowing the motor to my list of possible remedies ;)

For me, full-retard and premium fuel is working for now.

[2oodoor]

Great writeup Vanilla.

I know it's been a while but did you figure this out? I am experiencing very similar issues right now and am early-on in the troubleshooting phase. I can't use regular gas or it's ping-city! I've gone full retard on my timing too.

possibly an intake valve or two not seating well, or small head gasket leak not totally rearing its ugly head yet.. not much that hasnt already ready been covered in this thead regarding causes for ping or preignition and or preignition symptoms. Anything that is making the engine run hotter than usual too. No way in he11 would I run full retard, I would have to fix whatever the issue, that would annoy me to want to blow it up...hesi hesi heh heh hesitation

[2oodoor]

Well, I haven't had a single idle problem out of it in over a year.

that is hilarious dude, the comment not the other thing...

[g.frost]

Before you pull too many parts or hairs out, Put a full dose of PEA based detergent through the gas tank. (Like Redline SI-1)
Clean out combustion deposits that cause pre-ignition. Get it fully warmed and do some full throttle spirited driving to burn the crud out. Don't bother with stuff like MMO for this treatment; PEA is the best chemistry for this.