SCCS2K

ok update - just replaced the MAP sensor with a brand-new unit, cleaned the socket and channel.

...the problem persists, it didn't help whatsoever.

what's next? the dealer told me the IAC basically only affects idle, and is completely unrelated here.

thoughts?

SCCS2K

sorry for my ignorance...i can do that? literally unplug it and drive around? anything i need to know first?

slightly2ned

Sounds like an issue I have with my Toyota - same symptoms. Try checking to see if your cat is still good, if its broken/blocked, then it feels as if youre pegged with no power in the low RPMs. The engine is fine, however when at 65-70mph, it feels like it takes forever to get back to that speed after decellerating.

negcamber

I'm still thinking TPS or vac leak somewhere.

SCCS2K

It's so annoying that the TPS is bundled with the TB. I'm generally way too lazy to try to MacGyver my own...

bjjs2k suggested disconnecting the TPS and driving around. That's worth a shot if it's as easy as that...is it?

Don't you think if there was a vac leak, it'd always be bad, though, not intermittent? How exactly to I check for a leak, other than obviously listening for one from under the hood? I don't hear anything, for sure.

SCCS2K

Interesting, I didn't think about the cat...should that throw a code, though?

edhs2k

Before you throw a lot of money at parts, do compression test first. If it;s fine take it to good shop and for $80-$100 get it diagnosed. It's wll worth the time!!!!

SCCS2K

see, that's scary, but you're right.

years ago, as soon as i bought the car, i had the pleasure of being surprised with needing a complete valvetrain rebuild, thanks to the previous owner over-revving it. the repair (and paying for it!) was a nightmare, but it's been perfect for years since then.

that makes me wonder...since it had a valvejob when that happened (obviously) - are subsequent valve adjustments still done to the factory specs?

i ask because i noticed this low-rpm power problem beginning shortly after a valve adjustment a few months ago. i assumed it had to be a coincidence, but maybe there's some relation? i figured if the valves were so far off as to kill low-rpm power, i'd certainly hear it, and it wouldn't be intermittent...right?

regarding taking it to a shop for a $80-100 diagnosis, the local dealer (who i actually trust, surprisingly) is unable to find the problem.

SCCS2K

ok, update # 2 - i just cleaned the IAC and tightened the throttle cable (noticed it was a little loose). problem persists, no difference.

this leads me to the TPS, basically, unless anyone has any other ideas. the valve adjustment from my post above has me thinking as well, though...

on a side note - at the end of my test drive after the IAC cleaning, when i was putting up the windows - the car shook strongly, went quieter and acted exactly like it was stalling, although the revs weren't dipping. i could make this happen over and over again just by pulling up on the window switches, like it's putting a MASSIVE strain on the car. although this is new behavior as of right now, i don't think it could be related. (the battery is basically brand-new, btw.) any thoughts?

PWRMKR

Were you at idle?