here's the story I got the car with a blown head gasket which I have now fixed compression and timing are all good. now after a few weeks of driving it has started to hesitate from about 3 and not pulling like it should. now after another week I can start it but it will die shortly after and I want be able to get it started again.

Things I have done to try and solve it.

-Changed fuel pump to walbro 500.
-Changed fuel filter.
-Changed plugs to nkg platinum.
-Swapped distributor cap and rotor.
-Swapped afm with a turbo bluebird one.
-Cheeked for any boost leaks seems ok.
-Mechanic has looked at the vacuum lines changed one or to and got rid of my boost tap in case that was playing up so I would say they are all ok now but who knows.

None of the above made any difference could this be electrical or is there still more I can try.

Any help would be much appreciated.

Swapped afm with a turbo bluebird one.

54C has a unique MAF -- if you are running the Pulsar ECU, use the Pulsar MAF...

Yea its running factory maf now but is there any way of knowing if that's the problem.

It's always worth it to clean the MAF -- when I first dropped the Pulsar engine in my Sentra the MAF was dirty as hell. The car ran terribly. Rough idle, no power, etc. Shot some MAF cleaner on it and it ran great...

I have got another gti-r maf lined up is there any other things that could be causing my problems I herd that spark plugs make a lot of difference and also i was told that Nissan ignition modules pack up.