1999 chevy blazer wont start

not knowing the condition of you suv, replace fuel & air filters, very important, replace distributor cap & rotor, spark plugs & plug wires. that should do it, good luck

Blow out fuel line put 3-4 cans of dry gas & try again might have injector problem now

Could be the EGR valve or the idle adjust valve. Check Engine light on? Any codes?

Check the plug wire from the ignition coil to the distributor cap.
If you haven't already, replace the distributor cap and rotor.
The GM Vortec's have issues with moisture getting inside the cap and rotor and causing problems.

I’m happy to help further over the phone at https://www.6ya.com/expert/jason_00b31cc8f593773a

first check for spark disconnect any plug wire from the spark plug remove the spark plug from the engine reattach the plug wire and set it on the fender well DO NOT TOUCH THE PLUG OR WIRE AND CRANK THE ENGINE AND SEE IF THERE IS A SPARK BETWEEN THE ELECTRODE AND ARM. if there is no spark you have an ignition problem check for 12v at distributor.
if you have spark then check fuel pressure the fuel pump could be bad.

When you go to an auto store and they give sell you spark plugs they should already be gapped to spec. There is no need to adjust the gap. This may be the reason your car will not start. I would try new spark plugs first then wires. Since the vehicle is a 99 it probably could use a tune up (spark plugs, wires, coils, cap, rotor, chassis lube, and transmission fluid check and flush if needed). Also make sure that the engine block ground strap is in good condition and that there is no corrosion covering the ends of the ground strap. The ground strap is typically located near the firewall and is directly attached from the engine block to the frame of the car.

Check the wireing to the pump they had problems with it it tended to over heat and corroad there is a service bulliton on the prroblem #25215705and a kit with new wires and connector to resist over heating Icould give you the kit # but i got a DELPHI pump and the connector dosn;t fit a chevy pump

You are getting good spark to the plugs? Have to assume you retimed it after you changed the rotor and cap. Wires are good?

Could be the ignition module, but they usually are either good or bad and not itermittent(sp)...

If it trying but just not 'catching'.. seems like a timing issue, or possibly the coil (although coils tend to be good or bad as well)

Looks like you've covered the basics, make sure the firing order is correct with your spark plug wire replacement. Hope this diagram helps.

Test for weak spark when it wont run....my guess is that its the ignition module inside distributer...they heat up and shut off spark,then cool down and work again for a while...good luck..Lee