Engine misfire

[200sx-v8]

I'm having some trouble with my engine after rebuild with forged internals.
The engine sometimes misfires on rpms over 3000. When the boost comes on it always misfires a bit. It seems as a 2-4 cylinders are cutting or something. But the idle is fine, and mostly the cruising is fine.

Everything electronic is the same as last year, when it ran perfectly. Except for the injectors.

I have tried to change plugs, plug wires, coils, ignition modules and I have cleaned the rotors and dizzy caps. Checked the ignition timing and afr.

I'm using a microtech lt8s ecu, and it's showing no errors. Any ideas anyone. Have had this problem the last month now, so I'm starting to loose my patience with this.

I'm changing to bigger injectors tonight. But I don't belive they can be the problem. Since it runs fine on all 8 cylinders most of the time.

 

[200sx-v8]

I solved the problem today.

It was acutually the injectors that caused it. Installed my new Delphi 1000cc injectors and it ran very smooth afterwards.

Now I'm going to tune it on a dyno on Friday. Then we will see what power the T51R can deliver on this engine...

 

[V8Datto]

So what was wrong with the injectors?

to small?

Faulty?

 

[200sx-v8]

They must have been faulty.

It was used injectors from a skyline gtr.

 

[Lextreme II]

WOW... you are using 8 1000 cc injectors? That is insane. How much boost are you running or going to run? My project have 1000 cc injectors also but afraid the idle might be little rough.