I am new to the forum im having problems with a blazer i bought its a 1996 blazer 4.3 have had some issues with it just recently had random misfire and code for m.a.f. changed maf after that ran fine for a week .random misfire came up again .it stumbled while i was coming home parked it .wouldnt start but cranks.checked plugs wires cap rotor.fuel pressure at 61 ,compression good on all cylinders. i smelled gas when cranking but no leaks.fuel pump holds pressure good. plugs were pulled smelled of gas .put them back in sometimes will start but when it does it starts instantly .its at a garage they cant figure it out thought ecm was bad tried another still no start .battery good temp sensor good cam sensor good crank sensor when it runs it runs good also has a new ignition switch,and key switch .i follow this forum quite a bit would appreciate and advice or knowledge sent my way.fuel pump was changed 2 years ago. thanks

 

I had a fuel pump relay crap one time on my P/U (C1500)
SOB had random start issues

 

If its a no start, turn the key forward and listen for a buzz coming from the fuel pump, if theres not a buzz its either your fuel pump or pump relay. even if it was changed 2 years ago they will still go out, those fuel pumps suck.

For the misfire how did you check your plugs wires cap and rotor?
Whens the last time the where replaced?

 

yes plugs wires cap and rotor sorry for late reply im new to a forum.never been on any type of forum kind of lost .when this happened i checked them thought i would do tune up . still had a small miss.upgraded the spider to the mfi injector set up 2 years ago .fuel pressure key on 61 psi wait 5 minutes down to 58 . if one injector is possibly plugged or leaking doesn,t explain why all plugs are wet .fpr should,nt be leaking from results of the leak down test. checked also battery,ground wires cranks fine just wont pop off .tried a little squirt of starting fluid didnt work .i am getting spark just cant tell if maybe its not hot enough spark.thanks for your response and help.

 

changed relay no change thanks any help is great.i seem to be getting plenty of fuel all plugs wet ,can smell fuel .crank for a while crank crank .

 

Fuel pressure and leakdown are good. Sounds like an ignition problem. Pull the coil wire out of the cap, pull the boot back, lay the terminal about a half inch from ground and crank the starter. The spark should jump the gap with a blue, not orange, spark. Fairly common for the coil to arc to ground too: spray a mist of water over the coil and crank the starter, see if it arcs to ground while cranking. Very common for aftermarket distributor caps to fail too. I've seen some bad ones right out of the box, use AC Delco cap & rotor.

 

sorry its been so long it has been at a garage everything checks out but minute u turn the key it floods all cylinders.friend mechanic said check the spider.so i pulled it found everything washed .got another spider put it in .still no start.so i thought am i over thinking this.checked wires plugs cap rotor.pulled the cap expected rotor to be pointing to the 6 on distibuter.and its not pointing to the oposite side .so i rolled the engine over timing top dead center.checked again hit the key it fired right up and ran like a top .for 4 days no problems ,now dead in driveway again .checked cap same thing.took the distributer out the rotor appears warped .im thinking it jumped time not firing in right order flooding engine in fuel .havent had time to work on it till winter eased up brutal winter this year here. whats your thoughts.i dont get on computer much. im gonna pull the timin cover and check everything any tips?

 

I think you need to find tdc on #1 and make sure the distributor is correctly installed. Do a quick search on youtube for some videos, there are some real good shops out there making videos on them.

Also you need a scan tool to find out camshaft retard setting seeing how the distributor has been played with once up and running. Captain hook knows more about how to check that. I know engine needs to be running though and revved up to 2000 rpm etc.

If you have a timing light you could check each wire to see it's getting a spark when cranking it.

Double check wiring firing order.

Also there is some good distributor videos that talk about removing some vent holes in the distributor base to help ventilate the unit. All on youtube.

 

Check the memory for DTC's, if P1345 is present, the distributor is not installed correctly. No P1345 in memory, the distributor is meshed correctly.

Be aware that if you remove the timing cover, the crankshaft position sensor relearn MUST be done afterward. It requires a capable scan tool to perform the relearn, not all scan tools can do it. Timing chain issues are almost unheard of on this engine so you might want to check timing chain slack before you take anything apart.

Edit: Your fuel pressure and leakdown are fine. If the injectors were leaking, it would show up on the leakdown test, and it didn't. If the cap & rotor have crossfire going on, when you crank it, the injectors will still squirt fuel. Might want to consider installing an AC Delco cap & rotor.