Engine Pinging and lack of top end

I purchased a 91 Civic LX about 2 weeks ago (107000 miles) and there's every indication the car was well maintained. However I have a slight pinging on the engine around 2900 - 3500 rpm under load as well as what I feel is a general lack of top end grunt after 3500 rpm. I had this same car overseas (only difference was that one was carburetted vs FI on this one) and the car overseas would really start to pull hard at the upper end of the rev range.

This one by comparison really struggles at that rpm range. I changed the spark plugs, pcv, air filter etc and even ran some seafoam thought the vaccum lines as well as add some to the tank. Filler her up with 93 octane and the ping went away. However this morning I tried 89 octane and the ping is back.

Is it possible that the timing belt on this was changed, the it was aligned one tooth off or something. Any other ideas? Thanks in advance.

On tooth off would probably produce more than just a ping...check your timing, if it is advanced too far it will ping...

the lack of top end sounds like valve timing to me could easily be a tooth or two off.

but the pinging shouldnt be coming from that and you said it went awap with 93 which is more strange. i say pull the timing cover and set #1 to TDC and see if the cam gear is at the tdc possition.

Thanks for the tips. I dug up the ole timing light last night and I'll check the timing tonight. Does the Valve cover need to be removed to remove the timing belt cover?
Looking at it, there's a black piece from the valve cover that seems to be overlapping the tb cover.

Thanks

yeah you gotta pull it off.

I have a 91. I used a oil additive called Auto Rx. Then i went back down to 87 Octane . And the pinging went away.

Best of luck to you

Yesterday evening, I checked the ignition timing and it was way advanced. The marks on the pulley were over an inch away from the marks on the block (not sure how many degrees that is). I had to rotate the distributor all the way to one side to get the center mark anywhere near where it should be (it's still a tad too advanced).

The car drove much better after that and the pinging is gone and the top end is back. However, being that I had to go to the extreme on the adjustment range, I am convinced the belt is off a tooth or 2 at the cam.

Any idea how complicated adjusting the belt would be. I am hoping I can take the top belt cover off (along with the valve cover), loosen the tensioner and slide the belt over as needed. If this sounds right, what else do I need to remove to get to the tensioner? I looked at the Chilton manual and all of them have the tensioner adj as part of the belt replacement - where a lot of other stuff is removed anyway. Any ideas?

Thanks

One more thing, I am also accumulating oil on the #3 spark plug tube. I searched some of the forums and heard about the some seals that might be bad requiring the cam to be removed. However, is it possible for that to happen as a result of a bad valve cover gasket during the timing belt change?

More likely that it is just the grommet that actually seals the valve cover and the top of the tube. Grommet mounts under valve cover, can either replace, or try dabbing a little grease on it to reseal it.

Yeah, if you can loosen the belt then all you have to do is rotate the cams into position, but remember to retime the ignition because the distributor should be off again. And if I didnt readthat wrong, it sounds like im right on the ignition..could be a mix of both the cams and distributor though.

FordoGT: Yep - you were right on the money about the ignition timing. Yeah, I will remember to reset the timing after the cam adjustment.

Gunknad: your guess makes sense since I can see the trail of oil dripping from the top end of the tube (between the tube and the valve cover). If it was the other seals that I have heard some mention of - I am guessing the oil would be seeping in from the bottom of the plug tube.

Thanks for all yours' help on this issue. I'll post an update once I change the cam and get everything sorted out.