Misfire at high RPM's

[Donf]

based on the age the fuel injectors are dirty put some lucas fuel injector cleaner 5 oz per gallon of fuel will do the job

They were replaced last month. Thanks though

 

[Donf]

Well, I swapped plugs, no change, I swapped wires, no change. Dumped a big bottle of Techron in it, now just have to drive a few hundred miles and see.
Compression test if not better.

 

[BG1988]

Well, I swapped plugs, no change, I swapped wires, no change. Dumped a big bottle of Techron in it, now just have to drive a few hundred miles and see.
Compression test if not better.

not a fan of Techron

I bought chevron gas from 84k to 103k and my injectors were never cleaned


I ended up using lucas fuel injector cleaner which did the job...

 

[Fless]

Big fan of Techron additive bottles, but not at the pump. Girlfriend (wife, later) had a 1986 Bronco II that wouldn't pass emissions. The Ferd dealer cleaned the injectors and it barely passed. Two tanks of gas with Techron bottles added and the next emission test it passed with flying colors, and ran a lot better.

 

[OR VietVet]

The additives for the cleaning of injectors really kick in in the Plus Grade at Chevron. I use that.

 

[BG1988]

The additives for the cleaning of injectors really kick in in the Plus Grade at Chevron. I use that.

yes it was the premium grade fuel but I suspect they were cheating and putting 87 octane in the 91 pump ('premium fuel')
as well as a few other gas stations in the area.

you can tell because the AFM will hyperloop on/off rapidly and destroy the engine with 87 octane

it does not hyperloop with 91 or higher octane.... I have it disabled with a chip btw

 

[OR VietVet]

Even when I was in KC, Mo. and there were no Chevron stations there at that time but I did buy Techron and use it with good results. I know there are other cleaners but I know this has worked before and still does for me and I have no problems with my engine running the Plus Grade.

 

[exp500]

DonF- Were you able to get live data on your scanner? Might plug it in and see if your fuel trims and manifold pressure aren't wandering around While you are putting miles on her.