Help! Check engine light issues

[ri06667]

Last night my engine made a thump and the check engine light came on. It was running fine when i gave it gas, but when i idled at stop lights it was the rpm was fluxuating between 500 and 800rpm and it sounded like it was barely running.

I checked the codes on the engine and it brings up these two:
116 - Engine Coolant Temp higher or lower
538 - Insufficient Revolution Per Minute Change Dynamics
Truck is a 92 2.3 5spd.
Temp gauge on the dash works fine and never goes higher than normal, it wasnt particularly cold out yesterday either.

Any suggestions welcome!

 

[clem1414]

before you spend alot of money on sensors and they do cost alot (maybe).Check wiith ADVANCE or AUTOZONE or FORD SERVICE DEPT.I am going to give this a shot here goes.The 116 is the temp sensor underneath the intake manifold this is for your coolant.The 538 might be your MAP or your CRANKSHAFT SENSOR .Plus check your timing belt to see if you need a new one. Also when was the last time you tune it up.If it is been a while or too long tune it up first.Let me know what happens

 

[Bryan22]

if you got the 116 doing a test while engine is running, it could be that the truck wasn't warmed up enough. If you don't let it get up to operating temp it'll throw that code.

according to the tech library-

538 (R) System did not receive "goose" test - TESTS which means you didn't punch the throttle while doing the test.