Chugging Tbird

heliarc

Registered User
90 Tbird SC, 172 K miles

Does this when warming up ... not cold, not warmed up yet,
starts when you decelerate, as you are taking your foot off the gas, if you try any application of throttle after that, starts chugging, about 3x per second

If you pull over, shut off the engine and re-start - then everything
is fine.

Once warmed up - fine for hours.

Tried taking it down to drive from overdrive this evening when
it started - after a bit of tranny confusion, it was OK, shifted back
to OD and it was still OK.

Had it do something similar to this once, but was really limping,
and was bad no matter warm/cold/hot/restart - was the Cam
sensor that time.

Any Ideas ? Similar experience ? What should I keep looking for ?
Intend to continue trying the OD-D-OD trick for now to see if it is
OD related ?

thanks for any help
 
Well, for one thing - I'm not sure it's the trans...
Read a few of the trans-shop horror stories on this board
and no- I'm not ready for that yet.

Like I mentioned - it's done something similar in the past
with a cam sensor failure - don't think the amco guy's gonna
be much help there.

Thanks for the post though - better than nuttin I guess.
 
You should always start by checking for codes - sometimes you are lucky and the computer will tell you what's wrong (or at least what it thinks is wrong...). Probably not related to the transmission. Shifting from OD to D will bring up the RPM's so maybe that's why it helped.
 
Can you describe what you mean by chugging more specifically? For instance, is it like a miss & temporary power loss, or like a small reduction in back pressure when it occurs? Can you hear this or feel it? See if you can recreate the condition in neutral.
 
maybe it's another cam sensor. mine would jerk violently usually at highway speeds. i'd pull over, turn off and restart then it would be fine. it was the cam sensor. good luck
 
lot's of things

IAC sticking till it gets heat .. or you reset it by turning the car off and back on ...slap it into neutral ..when you let off the gas ..and see what the idle and vacume does... then back to OD give it gas ..OD to D I don't think will do to much for testing speed sensor


IAC gasket leaking

Dirty thottle plate allowing air past once close and IAC is trying to recover

O2 sensor getting weak only working once they warm up ..and calling for more gas when it's cold ..

bad plug or plugs .... gapped to wide or not enough ...could be oil fouled and needs the heat to clean them off

bad pcv filter ... forcing more oil into the intake from the vent being thicker when cold

maybe a dead spot in the ECT range

really need to look for codes first off

or none of the above ....dave
 
Resolution

Thanks for the help everyone,

Codes indicated cylinder ID failure,

Changed the cam sensor and the problem went away.

I had the AC converted to 134 not to long before this,
and I think some oil must have gotten dumped on the
cam sensor in the process (could see some in the well
when I changed it.)
 
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