86 GT slight hesitation, bouncy oil pressure needle question

[Andy]

I drove my 86 GT to work the other day. At lunch, I got in it to get
something to eat. After driving for 5-10 miles on the interstate, I noticed
that when I tried to accellerate, the oil pressure needle was pretty bouncy
(may not matter), the car would hesitate just a little and then it would
speed up. 1/2 way home my service engine soon light illuminated. I noticed
the hesitation more when I started from a stop. I was able to get all the
way home without breaking down but now I'm afraid to drive it to the shop
because I get the impression she isn't going to run much longer without some
attention. The service engine soon light did go off after a while but I'm
sure I still have some kind of a problem.

Not sure if that is enough information for anyone to have any ideas - my
thoughts were fuel filter or fuel pump. I have a new egr valve - that seems
to be a common source of problems. Not sure what else to try. I was going
to pick up one of those computer testers today and see if an error code is
stored.

Thanks in advance all!

Andy

[Andy]

I just drove it to the gas station, and put a full tank of 93 in it, checked
the oil and added about 1/4 - 1/2 the bottle. It seems like the hesitation
becomes more apparent the warmer the engine gets. Started to do the same
symptoms on the way back from the gas station although I parked it before
the trouble light came on. Is my next step to check the computer with a
tester I guess?

Post by Andy
I drove my 86 GT to work the other day. At lunch, I got in it to get
something to eat. After driving for 5-10 miles on the interstate, I
noticed that when I tried to accellerate, the oil pressure needle was
pretty bouncy (may not matter), the car would hesitate just a little and
then it would speed up. 1/2 way home my service engine soon light
illuminated. I noticed the hesitation more when I started from a stop. I
was able to get all the way home without breaking down but now I'm afraid
to drive it to the shop because I get the impression she isn't going to run
much longer without some attention. The service engine soon light did go
off after a while but I'm sure I still have some kind of a problem.
Not sure if that is enough information for anyone to have any ideas - my
thoughts were fuel filter or fuel pump. I have a new egr valve - that
seems to be a common source of problems. Not sure what else to try. I
was going to pick up one of those computer testers today and see if an
error code is stored.
Thanks in advance all!
Andy

[chrishizzle76]

sounds to me like your O2 sensor is going out or already is out. Or
you have a vaccum leak (likely possibility) because the engine is
losing too much power at once to take off.

[Andy]

Post by chrishizzle76
sounds to me like your O2 sensor is going out or already is out. Or
you have a vaccum leak (likely possibility) because the engine is
losing too much power at once to take off.

Thanks Chris! You win the prize.

I took the car into my Pontiac dealer and he said the O2 sensor was
literally broken off. Unfortunately this caused my oil / air mixture to
become overloaded with gas so I need an oil change, new O2 sensor and they
were going to flush the engine and go from there. I guess they need to look
at the catalytic converter once this other stuff is done too. I'll update
this thread once they have gone through the stuff they know I need.

[chrishizzle76]

lol yeah it sucks... mine was broken off too. Seems like they do that
alot..