97 BLAZER recently has a hard time starting

97 4dr 4wldrv blazer 120,000 miles car needed a quick jump sunday then started having a hard time turning over, but does manage to start if I rev rpms to 10 the engine soon relaxes a bit. and won’t stall. if i let it nearly stall i hear somthin like a belt squeeking til i shift in drive new battery installed <6mths ago but i’m suspicious of the alternator or perhaps the timing belt needs to be changed. last oil chnge suggested belt was almost worn out. Any ideas on the cause? ps y’all are my favorite weekend show so keep the smiles comin …lord knows the world needs to smile more but few can make car trouble into car laughter. Thanks for the many years you’ve given me!

Have the battery and the charging system tested. Many auto parts stores will do this free. You may have a worn alternator that is not keeping the battery fully charged.

If the alternator drive belt is loose or slipping it needs to be replaced/tightened. The noise you hear may be a loose belt.

Your engine does not have a timing belt, it has a chain, which does not need to be replaced under normal circumstances.