on the way to work this morning..i noticed that the RPMS were "jumpy"...didnt feel any shuttering,just a little loss of power,and the RPM'* wobbling around 1800-2400 at typical daily driving...im thinking either the MAF,or theTPS,cause the O2 sencor is new,coil pack is new,new plugs,wires....and it idles fine,which means that the IAC is good..


any ways to diagnose such a weird problem?

"typical daily driving" as in what? highway? city?

check for codes?

The ignition module (under the coilpack) is the source of the tach signal. Failing crank sensor could do the same thing.

this is normal city driving,usually nothing over 2,300 RPM...she stutteres after accelerating from stop signs..

Most likely ignition. Start tracking it down.

Both fuel and spark advance are influenced by the reported rpm. If that signal is erratic then nothing is going to run right. Might start just by R&Ring the harness on the end of the ignition module and the crank sensor connector.

This is the area where you really need a scan tool to find out what the computer "thinks" is going on but a jumping tach is a good indicator of a primary (low voltage) ignition issue.

Told ya smoosh, scantool is what you wanted.. I was right, once again!


-justin

And there are a bunch of OTC 2000s on e-Bay right now, have seen them go for as little as U$25.00. I have used an 89 GM cart with our 90 Bonneville but make sure the detachable GM cable is included as well as the right cartrige.

Last (and most desirable) Cartridge is the 1993 3in1 so it was replaced by the 4000 a decade ago. This keeps the price down.

ok,this is really starting to **** me off..
.cause i was driving today and took a shark corner and she stalled on me...cause it was downshifting +the sputtering RPM'*..

and also now in park the RPM'* jump from 1-2k..maybe its the IAC now?..can the IAC do other things?