Ok, a few weeks ago I posted something about my truck not wanting to start in the mornings, but cranking fine after being run for any length of time.

This all started after I replaced my alternator and battery, both have been checked and appear ok according to the local parts store(s). After some suggestions here I did the following; replaced the fuel filter, breather element, PVC valve, cleaned my KnN, and ran some injector cleaner through it. After this, all was well for about 40-50 cranks.

Then, yesterday morning it started acting up again. I was thinking of replacing the plugs, wires, cap and rotor. Anything else I should consider?

Something I just thought of while typing this. About the same time I noticed the drag in my morning cranks, I started buying 93 octane fuel from the local warehouse shopping place. My truck really does not like 82, and at this place the 93 is cheaper than any of the normal gas station prices for 89. Could it be that this engine is rejecting the good stuff? It's pushing about 175K miles and runs like a dream....once it starts....

 

your fuel pressure regulator might be going as well, have you checked it. the gas could be your problem, i would try one take of 93 from a real gas station to see if that helps at all. have you checked the timing, with that many miles it could be your problem as well. might also replace the coil to , not sure but worth a try.

later

 

in the morning turn the key to the on ponistion and wait til the buzzing/fuel pump stops then crank it

 

I do that every time I crank it, and when it's acting up, it still drags. I've even primed the pump by cycling the ignition switch a handful of times to no avail. Since posting my question, it's started fine every time - cold or hot.


This non-starting (for whatever reason) thing seems to be an epidemic with Broncos.....

 

Test the fuel pressure.

 

Like maybe your Idle Air Controller. Take it off and clean it with some carburetor cleaner, they can get carboned up after a while.

Billy: in the morning turn the key to the on ponistion and wait til the buzzing/fuel pump stops then crank it

Homie: I'm not a real big fan of that one. Hard on the fuel pump. If I was a betting man, I'd almost lay a beer on it being the idle air thingie. It acts as a kind of 'choke' on fuel-injected vehicles. Sometimes when you clean your throttle body, you accidentally clean some of the carbon off of the idle air controller (IAC) and it will straighten out for a little while. Try this: Pretend it's got a carburetur with a lousy choke and treat in the same way on cold starts--you know, hold the pedal down a tiny bit at cold start and pump it (a tiny bit) and if it reacts well, then it's most likely that idle air thingie. Mine does the same thing, especially when it's warm out. In the winter it goes right to high idle instantly but in the summer it sucks. Cleaning it might solve the problem, or it might cure the problem. I might break down and buy a new one for mine. Then again, I'm a little on the cheap side.

 

How exactly is letting the fuel pump pressurise the system hard on the pump? That's it's normal job, nothing out of the ordinary.

 

When the motor is running, the unused fuel returns back to the fuel tank, the fuel pump is running all the time. At start up, the regulator shuts it down when it over-pressurizes the system. Or at least that's what I was told. Makes sense to me.

 

It never "shuts it down" - it just restricts it to create a larger pressure drop, but it's still no problem for the pump. It has an internal overpressure valve.