mylsone

I changed my plugs to TR55's and now I have rough idle. Do you need to gap new plugs? If so how? Thanks!!

01Z0H6

iTrader: (63)

I too have changed to the TR55;s.
I have put these plugs in my car twice with no issues @ all.
To answer your question yes, you should check the gap before the install. They "should" be gapped @ .055!! Did you change your wires too? ,did you check your wires, to insure proper
fitment? Hope this helps. These are an Excellent plug for the LS1.

Fulton 1

iTrader: (9)

Yes, you should always check the gap on new plugs. As Pewter mentioned, the TR55's should come gapped at 0.055", but that doesn't mean you shouldn't check them (assuming that's the gap you want in the first place). To check the gap just pick up a sparkplug gapping tool at any auto parts store (a feeler gauge or the type with the little wire loops will work the best).

As far as the rough idle, I'd double check to ensure that all your wire boots are properly reconnected to the sparkplugs. #6 and #8 are always the most difficult IMO. If you have autotap you could also monitor misfires and see if anything unusual shows up on a particular cylinder.

dand35th

just make sure all wires are snapped on..

99 Black Bird T/A

iTrader: (4)

Update?

Was it a wire that wasn't snapped on tight?

Jabroni

FWIW, I just checked the factory gaps on a set of 8 new TR-55's. Of the 8, only 1 was gapped properly from the factory. Check 'em all!