1995 Saturn SL2 1995 Saturn SL2 (my mechanic is stumped by

First of all thanks for ur donation it really helps to keep this site going so we can answer everyones questions. Ok do u have any codes?If u don't know anyway u could have them read?I think what's happening here is u have a bad coolant temp sensor it's screwed into ur head below where the upper hose goes on. It has two wires going to it a yellow one and a black one going to it. Check the connector if it's corroded u will have to replace it. Make sure u get a brass tipped one the plastic tipped ones crack. Make sure u replace the bottom one with the two wires going to it with the colors I told u. There under 20 for the sensor it's ur best bet for what u described. Let me know what u find and how it runs.

here is a pic of where ur coolant temp sensor is located.i have worked for saturn dealers repairing cars over 16yrs i have only replaced a handfull of map sensors and throttle postion sensors in that time on the s model saturns they dont go bad often thats one of the last things i ever look at on those cars.the coolant temp sensors i have replaced over 100 thats probably a very low number saying over 100 i have know idea how many at this point they had problems with them from the begining on that model from 1991 till in the 2000 or 2001 when they changed it to a brass tipped.funny thing is when they were using a seperate gauge sensor till 1995 they were brass tipped and i hardly ever replaced those.but the plastic tipped coolant temp sensors cracked got coolant in them shorted out and will cause high idle overheating no starts car dieing while driving and then not starting surging bucking while driving idle thats searching not stable.power loss when opening the throttle bogging or delay in throttle reponse.a very over looked sensor that alot people just dont think about that it could cause so many problems.its job is to tell the computer what temp the engine is so it can run richer or leaner depending on the temp of the engine.lets say the sensor says 50 degrees but the engine is realy 200 degrees the car is going to run like crap because its getting way to much fuel.also if it says 200 degrees but is really 65 degrees then it will be starving for fuel.i suggest the coolant temp sensor because its under 20 and they go bad all the time and could cause the symptom u have.the other thing i would check on ur car is ur fuel pressure but unless u have a fuel pressure gauge then thats harder to test.also when u get alot of carbon in those engines it causes the valves to stick when u go from cruising to a stop light they will stumble and die out sometimes.not when excellerating that i have seen.anyways check it out and let me know what u find also dont forget to check the connector they get corroding from coolant and if its corroded replace it.also u want the bottom sensor with the two wires going to it.