Missing at high RPM

[Sagecoach]

Bought another GN. Has rebuilt motor 20M miles on it.Red"s 93 chip.Red stripe injectors.Otherwise stock.One lifter ticks at times.Idles and runs strong till about 4000rpm and then craps out.Almost like valves floating and occasional jerk.Scanmaster shows 840-870 02's with no retard.No error codes.Suspect coil pack.Don't suspect fuel system because o2 volts high.Anyboby had this problem?Any advice would be appreciated before I tear into it this weekend. Thanks.

 

[salvageV6]

Coil pack.

Beg, borrow, steal, a Caspers tester or use your spare coil pack.

 

[b231v6]

Coil or bad gas,, experience them both.

 

[BLACK6PACK]

Ditto on what has already been said. my car sat for about 2 months and the gas was bad. It had the same problem you are having, high 02s due to gas not burning and popping and surging.

 

[Sagecoach]

I have Casper's coil pack tester Will check the pack this weekend. Thanks guys!

 

[John Griffin]

Having the same issue... What did you finally find out?

 

[Sagecoach]

I honestly don't remember
It's been 12 years and I don't even remember which car it was (I had 7 of them at one time) Sorry I can't be of any help John.

 

[John Griffin]

Thats ok... just trying to find any possible solutions. 7 at one time!!! Man that is awsome

 

[Sagecoach]

Here's a good story for our turbo Buick community. Back in

 

[gnmaster2004]

plugs and wires

 

[UNGN]

For the idle tick, feel the cap of the Cam sensor and see if the tick corresponds to a tap you feel through the cam sensor cap.

My TTA has an idle tick and it is most likely the cam sensor gear because I can feel it in the cap.

By "otherwise stock" it has to have a replacement fuel pump, right? most cars should be on their 2nd or 3rd pump by now. If the car runs out of gas it may not knock or have low O2's, it just shuts off. Empty cylinders filled with just air may not knock.

My TTA ran like crap above 3K RPM for the last few weeks and I didn't think it was fuel, because I had a new fuel pump and a racetronics hot wire kit. After swapping out nearly every electrical sensor, it was fuel.