Engine will crank but wont start
 

Hey there, new owner and member here. Have been searching and can't seem to find a definite answer to my problem. Hoping its nothing to serious or expensive. I have a 98 4x4 4 dr with the 4.3 vortec. I haven't had any problems with it until now I just bought it a month ago, with 108,000. I am gathering its most likely the FPR but all the post with with pics describing how to get this done show an upper intake plenum thats cast aluminum while mine is a black plastic.

Now to describe the symptoms, Started her up tonight and kinda was sluggish for a second I didn't rev it up or anything and it went away. Drove not even a mile down the road and it died, would turn over no problem but didn't even try to fire. I turn the key and don't hear the fuel pump at all. Relived the pressure from the schrader valve and it barely ran out. Turn the key over and check for pressure and there is none.

What are your thoughts? FPR or Fuel Pump?

Thanks for any help seems like I have had a stream of bad luck here, The blazer replaced my 2002 Intrepid with a bad trans and blown motor.

I would check the fuel pressure with a gauge, but to me sounds like a fuel pump. These vehicles are bad for that. don"t forget to change the fuel filter to. You are probaly looking at the upper intake, it's plastic, the lower is aluminum.

Ive always known fuel pumps to slowly go out not just up and quit. But guess theres a first time for anything. The thread im referring to shows a cast upper with humps directing the air flow where mine does not. I have W engin code in my vin again its a 98 4.3 vortec 4dr. any other thoughts? I just filled my tank today so Im really hoping its not the pump.

I seen then just go out before. did you try hitting the botton of the fuel tank to see if it would run again?

Tried the hitting the tank this morning, thought maybe something would happen letting it sit over night but no change. Still cannot hear the pump turn on when I turn the key on. Are there any ways test the pump?

yes you need check the fuel pressure to be sure, make sure the fuse and relay going to the pump are good, but most likley it sounds like the fuel pump.

so talked to my mechanic today, he said to spray ether in the throttle body and see if it starts just to zero out the CPS. Well sure enough it started but obviously didn't run for long. Still no prime from the pump at all either, Thanks for the help!

Jack

You have narrowed it down to a fuel issue. If the pump isn't priming, you can try hot-wiring the pump. On a '98, this is accomplished by supplying +12V power to the proper pin at the relay. I know I have detailed this in the past and do not currently have time to go through it again. A search for "fuel+pump+relay+pin" with the author set to "swartlkk" should turn up the info you need.

will do a check real quick thanks for the help.

How do I know what is the correct pins on the relay via that diagram. Are pins 30 and 87 to the front of the truck or rear? If I'm standing on the drivers side of the engine bay, which pins do I need to jump on the fuel pump relay?

As I said, I have detailed this completely at least once. It may take some searching to find it though.

Also, please edit your post to include more information if another member has not yet responded. Rules of the forum and all. :icon_wink: