94 Vitara surging? timing?

[fixkick]

surging has 2 causes.
1: lean air fuel ratio
2: ISC is doing it.
The ISC can even amplify the lean surge, UGH!
the ISC can also fail to release as you step on throttle and even fight your right foot, surging, as you tip-in, if the TPS idle calibration is wrong and releases too late.
if engine has full power ,im sure the new MAF is ok.... sure it is... and very expensive.
market 24 car, that is good to know buying parts !

tps bad or set wrong.
or fuel pressure bad,, how is full throttle power? up hills. if weak , low fuel pressure if not gross misfiring.

im sure its a simple problem.
the filters clogged will cause the rear nipple test port to read 60PSI (wrong and shunted) at the filter 6mm banjo test port.
i just did one that read, 55, this caused low rail pressure.
it is a full flow filter so. must never be allowed to clogg.

once the filter is changed you will get 3 pressures good , rail or filter port
keyon 40s
start idle 30s
and then wide open throttle it will bounce near 40s.
this shows FPR as happy and good.