Has any one had problem with high rpms miss? It starts around 5000. replaced plugs, wires, opti, tried adjusting fuel pressure, and new coil. Any suggestion?

 

intake elbow?leak

 

new 1LE..more than likely not. it is only a few weks old.

 

try o2 sensors.could be other sensors like the map sensor

 

replaced both preccat O2s with bosch units and no change.

 

Have you made sure that none of the new wires are burnt because of not placing them in the right location.

 

put them back in the stock location. But, wouldn't a burnt wire would set a code?

 

Nope, to me, its sounds like a coil problem. So.....did you change the coil wire also?

 

new coil msd...2nd set of wires,,,first set was msd and second set are tpis. car runs better with tpis wires rised the miss high up in the rpm band. it was starting from 4500, but I have made many other changes it has move above 5 grand. I'm beginning to think it is the opticrap.

 

Maybe partal clogged fuel filter and/or injectors, that or valve springs getting tired?

 

fuek filter is new, it is the 3rd one since the new fuel pump.
I don't think it is valve springs because early mornings it is less likely to miss. there times when it runs almost normal (no miss) early in the morning. my thinking is the cooler dense air, which is easier to burn.

this is what leads me to ignition or air/fuel ratio. Thinking of running it on the dyno.

 

Not sure if that would cuase your problem or not, but be sure that the bottom of the intake elbow is on. Mine tends to get folded up/in some times.

 

I had about the same, turned out to be coil and coil to opti wire and....

my valve springs were way too weak for my cam. Maybe your valve springs are getting weak from age?

 

I'll check, thanx everyone for your help!! Back when it was mainly stock, I still had this same problem. I have been trying find what I did to start this dilemma. It has been driving me crazy.