ok, my .02 is this for the stumbling, COULD be a clogged cat, howver, my bet is on the throttle position sensor (tps) full throttle it boggs, then gets good at higher rpm, idles fine i assume, maybe a little "miss" here and there? as far as the radio, get a test light and check the wires. you should only have one wier that has constant power with the key off.

 

My opionion, that was a bad idea. Think about it for a second, how many people by 89? Its either the lowest grade or the highest. I have once scene someone by 89, and I wondered why. The longer the gas has sat in the tanks underground, more chance of water and **** going in there. Also, the fact that gas goes bad after sitting.

I would say burn all that fuel up, put in some fresh 87, as you will lose power with higher octane, there is no timing advance on the neon stock that will accomidate the increase in octance.

Goodluck

 

Thnx for the replies all. Mm, more info: Its throwing a code 21 which is an O2 Sensor problem. Also, it seems to not have the skipping/coughing problem when the car is cold. As I mentioned in my earlier post, if it downshifts the problem immediately goes away. Which would suggest its getting too much fuel. Whether its an actual physical malfunction somewhere, or just a confused computer becasue of a faulty sensor, hard to say. I happen to have an extra TPS from when I installed my 55mm TB, so Im gonna swap that out and see what happens.
~Sam

 

Ok, swapped out TPS and no difference. Also never mind my earlier comment about the hot vs. cold. I just got it to do it after running for only 2 min. So, O2 sensor perhaps is the culprit?

Ps. Iv'e also been running on 87 now for some time so, the probability of the 89 screwing with it has been ruled out.

 

Grr, It backfired really nasty today. this thing is kicking my butt.[:@]

 

Im having that proplem with the bogging realy bad when I floor it but it goes ok half throttle. This is im my 2.4 swapped neon I ran awsome and fast as hell then out of nowere it started this crap. Ive changed my injectors, checked wiring, and I think my oil pump is going out IDK yet when it is cold I can get my gauge over 75 psi easy but when warm no more than 52 psi my SOHC would peg 100 psi warm or cold. It all happened when My speedometer quit working no it just bounces up to 10 mph then drops. eeerrrrrrrrrrr!!!!!!!!!!!!

 

has anyone thought yet maybe to take a peek at the cam timing, if they jump one tooth, ive seen the sensor not throw a code on 2 of my cars and they run ****ty. or someone unhooks the battery before checking the codes and loses that one, then it PCM relearns it a tooth off.
i doubt 89 is gonna make it run bad...
god we run 110 in SOHC race cars to keep them from detonating when they reach 250 degrees and they still win races that way. 89 doesnt just sit in a tank forever. you need to understand how the tanks at a station work before you go nuts on that subject.
check your fuel pressure - low fuel pressure will cause them to seem to run fine most of the time but have random issues.
make sure the cat isnt plugged up
air filter?
check the spark, the coils get weak