1Bad93Z

I recently had my car dyno tuned and was very happy with the results, 398 rwhp
However after only 2 days of driving it I noticed a small hesitation at cruising rpms that progressed into an all out misfire at anything over idle rpm the following day. The coil, harness, icm, injectors, and opti have approximately 200 miles on them . I took it back to my tuner for a once over where he swapped out each of them except the opti with new components to test them with no change. He also reflashed the chip and tried a new ecm for fun. He said the misfire seems like its skipping around to different cylinders. After a little google research it sounds like I have a screw or 2 backing out. What have you guys experienced as far a performance when your screws have come loose? My buddy that installed my opti did not loctite the screws and said he installed a gm performance opti from jegs whatever that may be. Thanks if you read this far

SAPPER

iTrader: (10)

I had this happen in 96 or 97 with a new opti cap & rotor button. Destroyed the opti. I now use blue loctite on the screws.

1Bad93Z

Well we don't know for sure yet if that's what happened, the fact that the problem seems ignition related and that's the last thing we have not pulled. The tuner was hard pressed to believe that a gm opti should even need locktite but after reading several post it seems they are not immune to the screw problem either.

RamAir95TA

iTrader: (2)

An ignition problem that seems to be getting worse and worse would lead me to believe a wire/boot is burning and arcing more and more.

1Bad93Z

On that note the wires are new and that was the first thing he checked, condition, routing, etc.....simplest first. He also mentioned it seemed to skip from cylinder to cylinder.

93 LT1 Vette

I developed a miss at high RPM's. I changed coil, ICM, plugs, and wires nothing helped. Finally I bit the bullet and changed the Opti, rotor and cap but not before it left me stranded when it came apart. If it's the rotor loosening up, do yourself a favor and fix it now before your buying a new opti and a trip via tow truck.

1Bad93Z

It's getting pulled this weekend, I was more curious as how others car felt as the screws were coming loose. It's the last piece of ignition that hasn't been pulled/swapped yet.

adanp

I just changed my opti and when i get up to twenty miles it pulls back then i floor it ,it slowly acelerates

SAPPER

iTrader: (10)

In my case. It just shut off on her. I had just replaced the cap 2 days prior. So it was trailered home and when I tried to crank it over I heard it grinding, clicking etc.

1Bad93Z

Awesome, thanks...I'm hoping its just the screws starting to come loose. I'll really be at a loss if its not the opti, I don't have an issue fixing/replacing it. The part I'm worried about is the tuner, which specializes in these cars has said he will be completely stumped if its not this.

Speedy

It might not be screws. It can be a rubbing rotor causing fouling of the contacts resulting in conductive misfires. Take a look a the opti, I'm sure it has something to do with the installation of it.

FAD2BLK93

Possibly a carbon trail somewhere in the cap, check it carefully.

1Bad93Z

Yeah, really at this point as long as its opti related ill be happy just to get it figured out. I'll be sure to post back what we find.

matt94z

iTrader: (49)

Ive broken screws twice... both times shifting from 2nd to 3rd...

97Z28LT1

iTrader: (3)

When mine went out, it left me stranded. I was really thrashing it when it bit the dust. I hadn't notice any misfire prior, but the rotor was certainly very loose when I took apart the opti.