Qld:rb25det Not Revving Under Load

[sriver killer]

hey guys

here is the story...

i have a r33 series 1.5 1995

i was driving under load a while ago, then i blew a cooler pipe,..

after a comp test, i soon replaced my motor with a healthy rb25

after i did the engine swap, and got everything running

the motor doesn;t want to rev under load, it gets to about 6 grand then splutters

what i know:

there are no leaks in the intercooler piping

sparkplugs are new, changed spark plugs with bcpres11 gapped to 8 mm

brand ew replacement nissan coilpacks, 40 thousand kms

what i have checked:

replced coilpacks with another set, engine is still the same

some of the factory nissan hoses are split, the one on top between the two rocker covers

can;t find any vacuum leaks, or pressure leaks

the only thing i can really think of is my afm or ignitor pack or my aac valve

i haven;t checked my afm or ignitor pack, as i have nothing to replace them with

questions:

i looked at my aac valce on the back of the manifold, the purple plug that is on there it has broken off, but the wires are still in tact. is this a sealed unit? will it still work even though the purple plug on the valvebody side is broken off?

could the height of my sparkplugs be interfering with my coilpacks? sounds strange but i ran the coilpacks on teh sparkplugs without the coilpack holder holding them down and it went through every gear without popping under load???

i run a saas pod filter, would that interfere with the afm?

in the ignition line that plugs to all the coilpacks, there is an earthing line, does this have to be earthed in any special place? ie would the earthing of it to the coilpack rail interfere with whatever it goes to?

would blowing a cooler pipe disrupted something electronic?

is there anything else that i might be missing at all?

its a possibility that i could have gotten two dud sets of coilpacks, but i have tried mismatching the two sets for hours

any help would be greatly appreciated

[BH_SLO32]

Sounds like a fuel problem. Have you checked your fuel pressure? When was the last time you replaced your fuel filter?

[sriver killer]

no i haven't checked fuel pressure, what is factory fuel pressure?

the problem is intermittent, i'm leaning towards faulty afm, or dodgy fuel pump

would fuel pressure be different under load than when the car is at a stand?