1997 4.3 Vortec questions

[K5Titan83]

I know this is probably the wrong site for this but I haven't really been able to find a good answer for this anywhere else.

I have a 97' 4.3 v6 it has 250k on it and what happened was my fuel pump started going out in it and it was whining and became hard to start, well when I changed the fuel pump the whining had stopped but its still hard to start, it used to be one turn of the key and it was running and now I have to either hold the key for a while to get it to start or I turn the key once and it kinda sputters to life but some times I turn the key and it will fire right up no problem but, I woulda thought with a brand new fuel pump the hard starting would have went away.

I installed new plugs, but not new plug wires, and I have replaced the fuel filter in the last 3000 miles. someone told me the spider injection could be clogged but iv ran two bottles of seafoam through it each time using premium fuel, so im not sure where to go from here.

 

[79bonanza]

I had a similar issue with a 2003 4.3L pretty similar I'd guess. The fuel pump went out and I replaced it, proceeded to crank and crank and crank and prime and crank and prime the fuel system and then it finally started. It took long enough for the fuel system to get the air out that I started looking for other problems. Once it finally did start to run it ran rough for awhile then finally smoothed back out. I haven't had an issue since but I'd say that fuel injector setup has a lot to do with it.

I've primed a duramax with less trouble than that 4.3L gave me.

 

[ktmoutfront]

I just swapped out the old FI spider on a 2002 today. Hard start and surged while driving. Fixed that issue. Now if I can get the miss to go away.

 

[brans87]

i call it back tracking but what might be happening is the white part of the plug has a hair line crack in it new and is arching on that not going through the plug correctly. Had same problem on a gmc sonoma once put 4 plugs in new from ac delco and still misfire so threw wires at it still same problem, then pulled plugs back out to fine one had hair line crack barely see the line put in another plug and truck ran fine after that.

 

[ktmoutfront]

I have made sure that is not the issue. I have another thread going on this.

http://coloradok5.com/forums/showthread.php?p=3527467#post3527467

 

[K5Titan83]

i call it back tracking but what might be happening is the white part of the plug has a hair line crack in it new and is arching on that not going through the plug correctly. Had same problem on a gmc sonoma once put 4 plugs in new from ac delco and still misfire so threw wires at it still same problem, then pulled plugs back out to fine one had hair line crack barely see the line put in another plug and truck ran fine after that.

i put brand new spark plugs in probably a month before the hard starting started from the old fuel pump, and they acted fine, i suppose it doesn't hurt to check though, would bad spark plug wires do this maybe? or what about maybe bad distributor cap?

 

[brans87]

You can check cap for build up and ohm plug wires out

 

[919jackass]

there is a sensor on top i believe it's the map sensor you can take out to look down into and inside the intake. if you see fuel the spider assy. is leaking i have scene that and also the fuel pressure regulator on the back driver side of intake where the fuel line go into the intake.

 

[K5Titan83]

okay so I checked the plugs and they seem to be fine, so I got it in my head to replace the plug wires, distributor cap and rotor, I don't believe they have ever been replaced and the cap was cheap and the rotor wasn't a bad price either and so one thing lead to another, haha. so we'll see what happens after I finish doing those three things.