Starting "concern"

1996 GMC Jimmy SLS. I've looked at the "starting issue" threads in this forum but none are quite the same as mine. When you initially try to start the Jimmy (cold or warm), it seems to just crank for 20-30 seconds before it even tries to fire. New plugs, cap, rotor, wires. Battery is 2 months old, and so is the alternator. No idea about the relays or starter. It's not an intermittant problem either. This happens EVERY time you start the vehicle. The jimmy sat for a good while before we bought it, but would that cause the starting issue? It seems to run fine after it starts, but hesitates (stumbles)a little coming up off idle when its warm. Any ideas?

Have you checked the fuel pressure? Is the check engine light on? Any codes? When it is taking it's time starting have you poured a little gas into the throttle body or checked for spark? When was the last time the fuel filter was replaced?

Have you checked the fuel pressure? Is the check engine light on? Any codes? When it is taking it's time starting have you poured a little gas into the throttle body or checked for spark? When was the last time the fuel filter was replaced?


No lights on (though I have verified that they work when the key is first turned to acc), and no codes. The fuel filter was just replaced 2 months ago. Also, it does this whether its got a 1/4 tank or 3/4, no difference. Did check for spark while cranking, seems strong. I dont have the tools to check the fuel pressure on it, but I can take it to a friend who does. This may be totally unrelated, but the fuel gauge swings wildly the entire time we are driving the thing. I was thinking about fuel pump, but the guy we bought it from told us it was only about a year old.

Update:

Checked the fuel pressure, 62 psi with the switch on and falls to about 54-55 after about 5 minutes. I was told the fuel pump had been recently changed. New fuel filter too. I left the thing sit for about a week and it simply would not start. I could hear the fuel pump run for about 2 seconds every time I turn the switch on. It tried to catch twice but then just cranked. After about 10 minutes of that, and the battery starting to die down, I shot 1 little squirt of starting fluid in it and she fired right up as soon as I hit the key. Drove it around for a few hours yesterday shutting it off about a dozen times. It fired right up at the hit of the key every time. What in gods name is causing this? Could it be as simple as a dirty injector??

It wouldn't hurt at all to run some strong fuel system cleaner through it a couple of times to clean it out if you haven't already, make sure it's system cleaner and not injector cleaner. Fuel pressure seems fine, so does spark. You might be on to something when you question the injector.

I'm going to run 2 bottles of Techron fuel system cleaner through it and see what happens. I'll update after that.