I've got a 2000 ranger w 158k miles, been having issues with a missfire over 65mph, and it's been throwing a check engine O2 sensor code. One of the probable reasons for the O2 code read low fuel pressure... so my husband got the bright idea of replacing the fuel pump.

That turned out to be a big story in and of itself. BUT we got it replaced with one that works, however.... now it won't start!!! You have to pump the gas and like crazy and hope that it'll start, it will eventually... but not without a bunch of coaching.

Once it's running, it's running ok. The first day after replacing the pump it was AWESOME, ran like it used to years ago, no missfire, smooth as could be, no rattle, no check engine light. But it all came back it's missfiring again, rattling when you accelerate, and the check engine is back on. I haven't had a chance to go run and get the codes ran again, maybe tomorrow I'll be able to do that in between errands. Oh, and we are gonna replace the fuel filter at some point in this week, see if that helps.

But I just need it starting again!! I'm trying to sell this vehicle and this is not helping. So... HELP!! Any and all suggestions would be appreciated, we would really like to try and avoid $500+ in mechanic fees.

 

Back in the days of carburated engines, pumping the gas pedal would pump fuel into the intake manifold. Now, with fuel injected engines, "pumping" the pedal only flops the throttle plate back and forth. No gas is pumped.

When you turn the ignition key to the START position, do you hear the fuel pump run? If not you have an electrical issue. The electrical connection to the fuel pump may be dirty or, for some reason, makes a poor connection. If the pump runs, you may have a problem with the fuel filter or with the injectors or with the pressure regulator. Another possibility is that you have an ignition problem. Since the new pump seemed to work fine, then everything went down hill, I would first suspect a pump wiring problem or a fuel filter problem.

 

Well, that's good to know about the pedal pumping!! Ha.

I will double check, but last time we inspected, yes we did hear the fuel pump running. What's interesting is that, we initially put in a faulty pump and it died on us, we put the old pump back in to get the vehicle home (that was fun...) and even with the old pump it wouldn't start up properly anymore. We then got a replacement and that pump is working fine, I guess it started up just fine the first couple of times after putting in the pump, but then went to not wanting to start right away.

I'll pick up a fuel filter tomorrow and see if that helps! I hope so anyway.

 

Do a KOEO & KOER fuel pressure check at the on engine mounted fuel rail schrader valve test port & post the numbers. Good idea to get the computer scanned for trouble codes, so post All of the code Numbers, as you may have more than one problem & trouble codes can offer up good trouble shooting clues.

If your hearing spark knock/ping, it indicates a lean air/fuel mixture for some reason.

If it's past time for a fuel filter change, I agree it's probably a good idea to change it out, especially seeing as how you have a new fuel pump in place.

As michigan 66 said, fuel injected engines shouldn't have the accelerator flogged on a start, as holding it down opens the throttle plate & further leans out the air/fuel mixture & makes for a more difficult start on an already lean mixture condition.

On fuel injected engines, the computer properly configures the engine controls for a proper start, so all we need to do is turn the key. SO, if it won't fire & run, we likely have a fuel or spark delivery problem & from your description of how it's acting, right now I agree, it sounds like a fuel delivery problem.

When you turn the ignition switch from Off to Run, (before going to Start to crank the engine), do you hear the fuel pump run for a couple of seconds & stop???? If you don't hear it do this Each time the ignition is switched to Run, suspect a fuel pump electrical feed problem as michigan66 has suggested. So add the under hood fuel pump power relay & the in cabin fuep pump inertia cutoff switch, or their electrical connections or wiring, to your suspect list.

If you Don't hear the fuel pump run when it's in one of it's no start fits, thump the fuel pump power relay, or swap it out with a like relay not needed to run the engine, like the A/C power relay & see how it goes. If no joy, try thumping the inertia switch to trip it, then reset it & see what happens. If still no joy, try wiggeling the power feed wires & connections & listen to see if the pump runs for a couple of seconds & cuts off at KOEO.

If you still can't hear the pump run at KOEO, then break out your multimeter to see where the fuel pumps B+ voltage goes missing. If you have B+ all the way to the pump, check it's ground connections for loose or corroded connections.

A bunch more thoughts for consideration, let us know what you find.

 

I have the exact same problem but no engine light. Slightly rough idle, hard to start-especially when hot/low of fuel. I did not bother to check for codes since my engine light does not come on. I did buy a pump and filter, but I did not put either in yet. Mostly because I was never sure I needed the pump. Should I just change the filter and see how it goes?

 

If the fuel filter is due for scheduled maintenance replacement, or you don't know when it was last changed, by all means change it & see how things go.
Running the tank below 1/4 remaining isn't a good idea, as the fuel pump depends on fuel to keep it cool & happy.
If it still acts out after filter replacement, come by a fuel pressure gauge & perform a KOEO & KOER pressure check & a delivery rate over time check & post the Numbers.
I'd also do a scan for trouble codes as you could have pending codes stored that haven't turned the CEL on yet & that's assuming the CEL isn't burned out, it does light up for its KOEO self check....right???
EDIT: BTW Welcome to FTE.

 

Take the bed off if you are doing the pump. I just did it Wednesday on my sisters 2000 2.5L. So much easier than the tank drop dealie o.

 

How much voltage do you have at the pump?