Bumpin' Yota

You know what probably happened? It was there all along but now that you just got done working your butt off on this thing you were REALLY listening to the engine. Not just listening but LIIIISTEENING!! [/psycho wispering voice] (dane cook quote...sorry lol)

But now that you did all this work you really listened to the engine and picked it up now that you've got a keen ear to it. I think I did the same thing after my reshiming of the valves. I second most of what Gwhayduke said, well save the 4000rpm comment...

When I pulled my heads, OMG carbon everywhere!! Black piston tops black combustion chambers, carbon hanging off of the combustion chambers, etc.

WMI will get rid of your carbon though. Just have alooksie at my HG thread and notice the cyl with the HG rupture is CLEAN. Water kicks carbons hind end!

TNRabbit

Igwhayduke: f you read this thread, you would have seen that I just pulled & cleaned the injectors and did the Seafoam treatment. It ran fine after all that & I found my vacuum leak, but then suddenly developed this detonation/rattling between 48000 & 5200 rpms two days ago. I don't usually rev this high, but I was reveling in my newfound power after all the work I've done....

None of your suggestions would appear suddenly; those come on over a period of time the engine has periodically (if not daily) been run up to 5k rpms over the course of the past 6 years and it's always run great & never had any major problems other than replacement water pump & power steering pump @ 198,000 miles.

Bumpin' Yota

Hmmm interesting. Pull your EFI fuse or the battery cable for about 10 minutes. See what happens after you refire it up. Wasnt that the area you were having stumbling issues earlier? Perhaps the computer purposelfully leaned out the mixture in that area from the vacuum leak...even though you should be in closed loop if the pedal is floored.

I know nothing changed, but try and see if the timing did change. I dont see how or why it would change a lot but who knows...stranger things have happened.

Could the gas have some contaminents in it causing it that might have got in whilst you had the fuel rails off?

I know im going to have to drain my tank... Thats like 10 gallons of 93 octane im goin to loose too!

TNRabbit

Siphon it off into gas jugs!

Thanks, Bumpin'--I'll reset the EFI relay, check the timing, & try some new gas.

TNRabbit

OK, I put a tank of 93 octane in her and she shows NO SIGNS of pinging at all! Now, If I can just get her to do that with 87 octane....

Quick Question: When I jumpt the terminals, the idle doesn't change AT ALL. What would cause this?

ovrrdrive

I swear I've read that the idle not changing indicates a tps problem but I have not experienced it myself.

Btw, the higher octane fuel is a temporary fix if it ran fine on lower octane before. I suspect the problem will return shortly.

Did you check the EGR?

TNRabbit

I disconnected the EGR and experienced no change in operation, (except check engine light), so I reconnected it.

I know the 93 octane is a temp fix. I've Seafoamed her also in hopes that I just got bad gas in the tank. I plan to run it dry this tank...

I just adjusted the TPS and know that is NOT the problem....

gwhayduke

Yep, I read it. And I've posted a couple times trying to help you out. You obviously know more than me . Good luck on your own kid.

Bumpin' Yota

Easy there, I think he does appreciate your input (I know I do cuz I have the same problem) I think he's just frustrated and accidentally took it out on you. Interestingly enough his problem has been the same as mine ever since i reshimed the valves on my 3vze...i just chalked it up to not having heard it before i worked on it, put 93 in, backed it down to 10*BTDC (from 15*) it and never thought about it again...mine would still ping at a 55mph cruize or a slight application of throttle from a cruise.

Could this be some sort of sticking VSV, or a vacum tube leak? To be safe Im going to replace all of the vacuum tubes on mine and likely extend them so I can route them neatly from the VSVs to the intake plenum.

Do you think perhaps this could be sparkplug related? Im running the proper heat range for denso double platinums...maybe I should just go to the old NKG single ground base plug?

Right now im also cleaning all the carbon (lots of it) out of all cylinders and cylinder heads. Im hoping after all of this I wont have the ping, but its a worry in the back of my head....



Hey TNR, put your old plugs back in if you still have them...doing that would eliminate one variable...

TNRabbit

Sorry, gwhayduke; didn't mean to come across as an @$$hoal. I had just done the things you suggested and was a little perturbed from work, so you receive the brunt of it. Apologies!

OK, I fit the final pieces together this evening. For those of you doing an O2 sensor replacement for the first time, be sure to get A FLANGE GASKET & 12mm NUTS from the dealer before you pull the old sensor off! They don't come with aftermarket sensors, apparently (NFK).

Here's the pics of the old sensor after I Dremeled the nuts & broke them loose with a pair of vice-grips:




...and here's what the O2 hole looked like when I began taking the old gasket off (geez, it was like a part of the exhaust!):



Ran good when I took her out for about a 5 mile test drive. Seems to be running good--no hiccups at all and I actually hit the REV LIMITER (woohoo!) going down a long straight!

I'm going to end contributions to this thread and if I ever find out what is causing the pinging, I'll start a new thread & share it with you all. Thanks to everyone who gave sugggestions & encouragement!

Bumpin' Yota

Hey! I still had some in depth questions too! lol