1990 runs like poorly when outside temp is high

[TurnNburn]

Have been having some trouble with the engine hesitating, bogging down and then dying for about 2 weeks now. Fires right back up but still runs like crap and will die again unless i keep the RPM's above 4k. If it sits for even a few minutes it will run normal. I recently got around to installing my wideband and found out that i have been driving around town with an air fuel ratio between 10-12 to one... what?! and when it starts to act up it pegs the gauge to 10.0, which is maxed out, so who knows what it really is at.

Seem like a MAF problem that i had before so i swapped one out (man it is really hard to find the metal MAFs). and it didnt fix it.

Got the car hot. without turning the car off, i disconnected the oxygen sensor and random misfire i have had forever went away and the AFR's went up to 13.2 and hung out there. I proceded to flog the car to within an inch of its life and it runs great, a bit rich as expected as it is now is default mode without a signal, but way better then with it attached. Which is good, seems like the sensor is bad.

I drove it like this for 35 miles. Started it up and drove 7 miles to work. so 42 miles total and i have still not thrown a check engine light. What the heck is up with that?

[wtdash]

Yeah...the O2 may not cause a CEL. You can still see if there's one 'stored' - code is 32.

TD

[TurnNburn]

really? seems crazy that this wouldnt immediatley cause a CEL for no signal or low signal voltage. Especially with it running so badly it would have caused some other codes. i wish it had, would have saved me 50 bucks...

[wtdash]

Here's ONE (old) example of no CEL w/the O2 unplugged.

[TurnNburn]

interesting... thanks for the link. The car is going down tonight to pull the cams for a regrind, but i will slap a new o2 in and repost if it fixes it.

[Legacy777]

How old is the coolant temp sensor? That may be something else you may want to consider replacing if it's old.