DriftR

iTrader: (4)

Im the original owner, and the motor is all stock internals with 170k on the odometer at the moment without a re-build. Motor has been strong all it's life and since getting married it has only seen occasional weekend drives and slightly spirited driving. I decided to freshen it up with some routine maintenance and put new Auotolite Iridium plugs in it but before I swapped out the wires I noticed a hestitation when tryining to accelate from lower rpm's while driving. Once the rpm's picked up, It pulled hard right to redline. If you didn't get on the gas too hard, you would never notice any hesitation at lower rpm's but steeping it out from around 2000 rpm's it would break up and hesitate.
It has been like that for a month but last weekend I put my foot in it a bit and all of a sudden something let go and it does it all the time, like it's running on 7 cylinders. The exhaust smell seems different and you can detect raw gas in it. I thought a wire may have simply come off but they all seem to be on good.

Where should I look first... could this be the opti or should I be doing a leak down test, maybe lost some exhaust valves?
It's not burning any oil and I pulled the drivers valve cover which I suspected was the noiser side and no broken valve springs and clean as a whistle inside! One thing I did try was pulling off one wire at a time while it was running and oddly it seemed somewhat smoother idling when a wire was pulled...

Any HELP?

myltwon

iTrader: (1)

What is the plug gap at? Maybe you cracked a plug while changing them? I would pop the hood at night and look for arching.

96z28_lt1

iTrader: (3)

definetley look at night for arcing, opti is always a culprit but always save that for last because for the most part a lot of the times thats not it. when dide you last do cap and rotor though, or even just replaced the opti?

DriftR

iTrader: (4)

Thanks for the quick replys... and the advice. I finally got a chance to look under the hood at night and I see the coil wire pulsing dim light through it and the plastic side tabs of the coil itself pulsing light as well. It's not super bright but it is easily discernable... That's not normal is it? The plugs are gapped to .055 and I didnt see any other bright arching around either side of the block. The cap and rotor were done a couple years ago along with radiator and water pump but only have about 5 thousand miles on them. I had to replace the ICM last year.

Formulaslp95

Auto light is the first problem. I ran those on mine and they only lasted a few days I went with regular ac Delco plugs non platinum gapped at 50 ran great more power it doesn't take much to foul an auto light from my experience. Is the opti am oem or is it like an accel or msd?

DriftR

iTrader: (4)

The opti is OEM Delphi. Should I be seeing light pulsing through the coil wire and around the base of the coil at night though?

96z28_lt1

iTrader: (3)

I've never had a problem with autolite plugs. But OP you should not see any pulsing coming from the coil, its leaking electrical current, on shbox website he has a way to test the coil

Blue96Z28

Doubt the plugs are the issue unless one was DOA\damaged in install. Autolite is recommended by the majority of LT1 performance shop documentation I have seen. Both LE and Golen Engines recommend them with their builds.

draggin97s10

iTrader: (2)

Plain jane plugs are always the best from my several experiences... I will never run an iridium or platinum or blah blah 4 sparky special this that...you get the idea. I don't understand what you mean about a coil wire pulsing, or dim light???

draggin97s10

iTrader: (2)

Right, the standard autolites like 103's or 104's or 106's not the iridium's?

Formulaslp95

No the base of the coil could have a small hairline crack allowing spark to jump take the coil off have it tested maybe get a new coil and coil wire and see what happens it could be losing to much spark between coil and opti