VN misfire

[IhateRICE!]

hey all
i've been driving the ss lately and the tacho has be really erractic and the motor is misfiring and feels gutless and the volts on the MAP sensor is fine. i did a code check today and got a code 22. which is a TPS saying the voltage is to low. so i check it and it shows 4.9. and it says it's spose to be between 4 to 6 votls it's got me F#*ked

any help would be great

[88GreenVN]

Dizzy cap/rotor button
Plugs n leads
Injectors clean?

[IhateRICE!]

dizzy seems fine. plugs and leads are fine check all them today. and i changed my manifold to a torque power manifold with a top mount throttle body. so i changed the o rings and the mesh things on top of the injectors.. when i back probed the map sensor it didn't read any vots at all. sign of it being stuff. and also change the vacuum hose for the map sensor to..

[Cheap6]

Did you clear the codes, drive and recheck to be certain that there is a genuine fault present?

The TPS and MAP sensor (and MAT sensor) share a 5V reference. This is the grey wire to each, C14 at the ECM and should read, funnnily enough, ~5V relative to earth with the ignition on.

The blue wire to the TPS, C13 at the ECM is the TPS signal wire and should read < 1V relative to earth - the exact value depends on the model - with the throttle closed rising to the maximum ~5V value as the throttle is opened.

The light green wire to the MAP, C11 at the ECM is the MAP signal wire and should read ~1V relative to earth at idle rising to the maximum ~5V value as engine load increases i.e. drive up a steep hill +/or check with the engine off.

[IhateRICE!]

i did a erase memory. and try and reset it but when i try to rev it to 3000rpm it just misfires and carry's on. my tacho is really erratic and sometimes peaks at like 5000 to 6000 thousand when your now where near it. like driving along and slow down using the gears and it does that. any more idea what it could be?? computer problem? ignition, fuel pressure??

thanks for the help

[IhateRICE!]

how much does the spark lead resistence matter.??? if it to low.