What would cause all this?

[Devin Wright]

Well, this is really hard to explain all this. But, my Explorer starting doing this about 6-8 months ago.

When you crank it up, even if it's the first startup, it'll start, idle highish for a few seconds, then drop down from 1200RPM's to like 300RPM's, then back up to 1200RPM's, and repeats that.

If the car has been running for a while, and the engine is warm, right when I crank it up I have to immediately throw it into gear or it'll just die on me.

Also, even if the engine has been started from the first startup, there will be times where if I come to a stop it'll die on me. Like, just going down the road sometimes slowing down it'll just die. Kinda scary driving when you have to stop randomly and pull off to the side of the road to start your car back up.

What it also does this time of year, during the warming years, is it'll not at all wanna start. It'll sit there and crank and crank and crank, but will not fire. And I won't hear the fuel pump's buzz when it kicks on. And I replaced the fuel pump assembly about two years ago because during the summer time then, it was 50/50 if it would start or not.

During the winter time, I always hear the fuel pump kick on and the car start. During the summertime, it's 50/50. I've figured out a thing where if I take out my fuel pump relay and put it back in, it'll start up. But, sometimes I'll have to do that 2 or 20 times. Driving this car is getting reaaaaally annoying.

But, as I really can't just shell out the money for a new car, what could cause all these problems? This is becoming a pain in the ass, and considering I now have two jobs and work 65-70 hours a week, I REALLY need a reliable car. Sometimes I'm lucky enough to get to drive my roommate's car when mine is acting up. But, he has a job too. And he's not always off on the days I work.

But, enough rambling. If you amazing people could perhaps help me with figuring this out, I'd love you guys forever.

Car: 1995 Ford Explorer XLT, 189k miles.

 

[seville009]

Have you checked for codes? Those should steer you in the right direction if any exist. Even if there are no codes, that kind of helps because at least it’s not something “hidden”

 

[974X4BLACKSPORT]

FOr your first problem with the idle up and down, sounds like a vacuum leak, check vacuum hoses and upper/lower intake manifold gaskets, plus idle air control valve.
For your second problem, try replacing the fuel pump relay, and verifying proper fuel pressure during cold start, hot start, and under load conditions.
Have you replaced the fuel filter?

 

[Devin Wright]

FOr your first problem with the idle up and down, sounds like a vacuum leak, check vacuum hoses and upper/lower intake manifold gaskets, plus idle air control valve.
For your second problem, try replacing the fuel pump relay, and verifying proper fuel pressure during cold start, hot start, and under load conditions.
Have you replaced the fuel filter?

I actually have replaced the fuel filter. Bro, I've done so much stuff to this car, easy to forget! lol.

But, something I also didn't mention, and this might not matter too much or would make since. But, when it does idle low, you can see the battery hand go up and down. And, if say I have an interior light on (also can see this with my exterior lights.) that when it does idle low, they go dim.

 

[rasouth]

I would say that if your battery gauge is going up and down and lights are dimming when idle is low you might want to check your alternator. It's your alternator that runs your electronics when the engine is running. You should have around 14 volts at battery when engine is running. Low electrical output could cause fuel pump issues, weak spark at the plugs, not enough power to run lights...

 

[Mbrooks420]

I’d clean the Idle Air Control valve.

 

[BUXTER]

Ditto IAC & yes often it throws no codes - With motor cold & snorkel off u can try shooting some spray Seafoam thru it while idling … OR just replace it.