Ok I have a 2000 Blazer with 4.3. If its cold out I have to hold the gas to the floor before turning the key on or it's a nightmare to start. seems to be ok once its run for awhile and then try to start it. Also throwing code for random misfires and I can attest to it. Any time I give it gas or rev the motor I can hear and feel the misfires "a lot of them".

This is what I've checked and replaced so far.

Plugs
Cap and rotor
Air intake temp sensor
Distributer timing gear
Checked Fuel pressure

"DO THESE REQUIRE THE PLATNIUM PLUGS" I have heard some of the S-10 series don't run right without thembut not sure if it's accurate or if mine applies.
Really want to get this back on the road but With it running this way I don't want to get stranded and I don't know where to go next.

 

These things are very fussy when it comes to tune up parts. They like AC Delco 41-993 plugs, a good quality plug wire set, and last but not least, use AC Delco distributor cap & rotor only. Don't waste your time, money, or sanity with aftermarket stuff.

After you replaced the distributor gear, did you check and adjust camshaft retard? It's part of the job, and it must be done whenever the distributor is removed. It requires a high end scan tool, the El cheapo $500 jobbies can't access the data stream.

What were the results of the fuel pressure and leakdown tests?

Does the check engine light work?

Is the check engine light on or flashing while driving?

If so, what DTC's are in memory, and what order are they in?

 

check engine is on all times not flashing. codes are 1st : Multiple random misfires 2nd: Multiple misfires on #4

I used ac delco plugs but not the platinum. Would plug wires cause multiple random??? I would think it would be on one cylinder??

 

What part number spark plugs did you use?

Faulty plug wires will definitely cause P0300 and P0304.

What brand distributor cap & rotor did you install?

Did you check/adjust camshaft retard after replacing the distributor gear?

Each one of these can cause misfires.

 

The cap and rotor were farm and fleet and as far as the cam shaft retard, this is actually the first Ive heard of doing it and I have no idea how!

Now I feel like an idiot!!! Should I?????

I have a innova computer I hooked up to see the real time and I'm not sur if this is normal but the ignition advance is all over the place.

 

What part number spark plugs did you use?
I realize the cap & rotor are from Farm Fleet, but are they AC Delco parts?
The wires are due to be replaced at 100K miles. Good quality, not some cheesy store brand.

Adjusting camshaft retard is done by viewing the live data stream on a capable scan tool, while slightly rotating the distributor to bring it within spec. The procedure is similar to adjusting ignition timing on a 1970's vintage vehicle, but rotating the distributor on your vehicle, does not affect ignition timing. Very important that camshaft retard is within specs. When you remove and install your distributor, your odds of getting camshaft retard correct, are about the same as winning the lottery...twice If you don't have a high end scan tool, take it to a qualified technician that is familiar with what camshaft retard is, what it does, and how to adjust it. In the meantime, make sure you have AC Delco plugs, distributor cap, distributor rotor, and a good quality set of plug wires installed.