odd idle, acceleration bog

[bbender85]

hello, some of you may recognize me from clubgp, efi, or wbody... but here goes.

1995 GTP, goofy idle and a power loss under acceleration. idle goes up and down, up and down... kinda like a leaky intake gasket, but sometimes it just up and stops; idles fine, like it snapped out of it. under modeate to full acceleration, engine feels underpowered, but to let off just a little it feels/sounds healthy. that kinda seemed like secondary ignition to me, but plugs, wires, and icm are all brand new.

any ideas? fuel system, EDIT: sensor of some kind, maybe in fact intake gasket? (which seems unlikey; been replaced three times, twice during the timing belt job and once a few years back.) any input appreciated, thanks guys.

[d.o.h.c]

i have the sam proble but not under a loss of power and i just did my intake gasket. i will redo that and see if it works and will get back to you

[d.o.h.c]

DO YOU THINK IT COULD HAVE ANYTHING TO DO WITH THE 02 SENSOR

[stantmann]

Possible vacumm leak. If you've checked for leaks. look for a worn vacuum hose, especially on the the MAP sensor.

[pocket-rocket]

Clean the IAC pintle maybe? Could be carboned up some. Run some GM TEC while you are at it. Carbon sucks, lol.

[stantmann]

It very well could be the o2 sensor, but as many of us have posted before, with a bad o2 sensor normally comes with a clogged or partially clogged catalytic converter. It backfires on you, then I would go that route first. Look at the converter at night and see if it is orange hot. Then you'll know...

[93luminaz34]

My car had very similar symptoms that were caused by the timing being wrong. My timing belt tensioner had gone bad causing the belt to slip and lose the engine's timing.

[pocket-rocket]

Another note, under WOT, the O2 sensor is not used by the ECM. There is someone else here on the board I was talking to the other day that pretty much has the same problem, but his is only acting goofy at idle. I suggested to him to check his fuel pressure to see if the FPR is going.