Hi everyone. First time post here and new member. I am having a problem that no one seems to have an answer to. I have a 98 blazer the 4.3 vortec, it only starts if I boost it with my charger. Fuel pressure is @ 59lb. I am gettin spark. I gave it a small shot of starting fluid and still fails to start...untill i boost it. Brand new battery as well. The only code auto zone gives me is P0453 for the tank pressure sensor. from my understanding this should not cause it not to start. new ignition control module, new coil, new cap n rotor and plugs. no excess smell of fuel anywhere either. Runs great once it is started....any suggestions or ideas on things I can check?

 

What brand tuneup items did you use? (Cap, rotor, wires, plugs) These blazers are picky on those. In fact i think i remember a fellow member here posted once that he did a tuneup with bosch plugs and it went from running rough to a no start condition immediately upon changing to them. The plugs were the culprit in his situation.

 

Well I don't remember what the cap n wires were, but I can tell u I had this problem before I changed those items. I do remember I had ac delco plugs and during this problem I put in champion plugs. Still the confusing part is everytime I boost it...the darn thing starts. Thanks for your suggestion I think I might go get another set and try it. If that is not the problem I'll have new plugs for my next tune up. I'll post in a couple of hours and let ya know.

thanks

 

well not so good news...my own diagnostics evidently failed (reason I am not a mechanic). just for fun I checked the fuel pressure AGAIN and the reading is 52. A shot of starting fluid will make it fire of course but won't start. If I boost it...of course it will start. How do I test the relay? hopefully this could be a simple problem and avoid purchasing a new fuel pump. Any ideas? I have heard after market fuel pumps for some reason the connections will go bad at the fuel pump and can easily be fixed.

 

It's probably the pump. Relay's either work or not in most cases. The only other thing it could be is the fuel pressure regulator, however that's' a far less common failure. Click the link in my signature for the DIY section and go back through all the testing procedures for the fuel system. Make sure you didn't miss anything. You will more than likely find it's the pump, But double check to be sure.

 

Well the problem is fixed...what should have been a couple of hours was ALLL darn day! Fuel pump was the problem, but not before the stud to hold the strap on the front of the tank broke...as well as the stud that hangs down the the rear strap twisted and snapped off as well. Also the lil plastic (tank selector) piece toward the front of the tank on top broke as well when pulling out the tank. 2 hours at a junk yard saved me almost 75 bucks. Found good straps and a tank selector. the whole 9 yards for 10 bucks. Next time someone else is doing it.

 

What do you mean "tank selector" I'm lost here......got a pic of what you're talking about?

 

Bet he means the vent valve nipple. Good thing his vent was the replacable type, mine wasnt.. so I had to get inventive.




Actually the reverse. The OE wiring connectors often go bad. The Aftermarket pumps themselves aint up to it.

Perhaps the beginning of that is old style of several years ago before all new pumps came with new style harness connector.

 

Mine wasn't either, I wound up having to get a new tank cause of HOW it broke. You got lucky there (or my mechanic just got stupid)