95 monte carlo 3.1 won't shift ino fourth gear
 

Hello everyone. I am a proud owner of a 1995 Monte Carlo LS, 3.1, with 194,000 miles, and trying to work all of the bugs out. I have been doing alot of research on this forum, and have gained alot of useful information, but I need a little help please. Let me start from the beginning. I have owned this car about 3 weeks now. I have always been an import kind of guy, but my main car's transmission went out, and I acquired this for a decent price. Anyway, I am trying to get is running the best I can, because it is now my daily driver. I have to replace the fuel pump, and filter, because my fuel pressure is alittle low, and I car hesitates when I take off. I just changed the thermostat, because the car wasn't reaching operating temperature. Now to the main problem I need some help with - I drive mainly on the interstate to get to work. I have noticed that most of the time, my car will not shift into fourth gear. It wants to stay in third, and going 70 mph the rpms are at 3,000. My service engine soon light comes on usually everytime I drive on the interstate after about 20 minutes of driving. I have tried checking the codes with a OBDI and OBDII, and it won't pull them. Now, since, I have been reading on this forum, I tried this last night. I turned the key off and on while on the interstate, (I don't recommend this, by the way), pulled over, and cranked the car back up, put it in OD and took off. After doing this, the car shifted through the gears and went into fourth. So I continue to drive home ,and about 15 minutes later, the car falls out of fourth gear and the rpms go back up, like it is in third. Does this sound like a major transmission problem, or maybe the shift solenoids, or what? When I drove it last week, the car ran all week shifting into fourth. It seems to have a mind of its own. I thank you in advance for reading my rambling, and look forward to getting some insight in this problem. Thank you!!

I'm not very knowledgeable in transmissions but as far as reading the check engine you're going to need a obd 1.5 reader. In 95 they used a in between obd known to some as the bastard

if the car hesitates when taking off, you may have an engine related problem that is affecting transmission operation. 95-96 used a vaccumm modulator to control shift points, shift solenoids, and a tcc solenoid. The engine code is vital in diagnosing your problem, ie. is it dropping out of fourth or convertor lockup?

Where can I get the codes pulled?

Oreillys auto parts will usually scan it, or other part stores