99 Explorer Eddie Bauer

[99Ebauer]

Hello everyone, I’ve got a 99 Explorer Eddie Bauer edition with the 4.0 SOHC engine and 356k miles. I’ve got a weird issue I’ve been looking into, wondering if anyone else experienced the same thing. When it gets over about 100 degrees outside, when from a stop and you get on the throttle it feels like it’s struggling to get get fuel in it, almost like a throttle positioning sensor cutting out, or like there’s fuel cutting off or something along those lines. Then once you stomp on the gas it will feel like it’s clearing out and run fine until you stop again or get it down to lower rpm’s. Check engine light doesn’t work at all, but it’s only ever thrown a code once when it does that, 171 and 174 lean conditions. Ran fine all winter and spring until it got over 100 and now. Anyone else experience the same thing and if so what was the fix?

 

[Mike65]

Welcome to the forum. Did you try checking the fuel pressure?

 

[BrooklynBay]

Welcome to this forum! Those codes point to a vacuum leak with the manifold intake gaskets.

 

[99Ebauer]

Welcome to the forum. Did you try checking the fuel pressure?

Thanks! Yes I just got done with that today, idle was at about 55 psi. Then when I shut it off, after about a minute the pressure dropped about 15 psi. Going to swap the fuel filter when I can because it does look pretty old, and hope it’s not the fuel pump. Maybe a vapor lock?

 

[99Ebauer]

Welcome to this forum! Those codes point to a vacuum leak with the manifold intake gaskets.

I’ll smoke test it when I bring it back to work, see if I can spot any leaks.

 

[donalds]

55 psi is low should be 62-65
Change the filter and recheck
If its still low then time for a pump

 

[Fix4Dirt]

wow! 350k? thats great on a SOHC!!!! this one has 332k with an intermittent odometer, so for all i know its about 350 haha keep em going!

 

[99Ebauer]

55 psi is low should be 62-65
Change the filter and recheck
If its still low then time for a pump

So after buying my own tester, have it hooked up and at idle it’s at 50, turn key test is at 30-35, and at any rpms the pressure stays at 50, sometimes fluctuates down to 40-45 when snapping throttle open. About to swap the filter so I’ll see how these results change.

 

[donalds]

New pump and filter time sorry
Here is a guide on how to replace your pump
Its using my 99

Is my fuel pump bad 1999 ford explorer shoc 4.0. Lots of pictures on the replacement

How can I explain this

www.explorerforum.com

 

[99Ebauer]

wow! 350k? thats great on a SOHC!!!! this one has 332k with an intermittent odometer, so for all i know its about 350 haha keep em going!

100%. It looks like at some point the engine and transmission have been replaced. Got pretty lucky to find this truck though! Just have to do that fuel pump which shouldn’t be too hard

 

[Mike65]

I did one on our 99 Sport in our driveway on a cool fall day the same way donalds did his in the write up. I removed the complete pump module & just replaced the pump part with a Bosch pump. Just make sure the tank is very low on gas, it makes it easier to control when lowering it down on the floor jack & be careful of the lines on top of the tank, so you do not break them.

 

[Fix4Dirt]

I did one on our 99 Sport in our driveway on a cool fall day the same way donalds did his in the write up. I removed the complete pump module & just replaced the pump part with a Bosch pump. Just make sure the take is very low on gas, it makes it easier to control when lowering it down on the floor jack & be careful of the lines on top of the tank, so you do not break them.

metal line removers help the plastic ones ive snapped metal has worked the charm and just take your time and itll work it ajn hard jus tedious smetimes

 

[99Ebauer]

So I wanted to let you guys know, I don’t know if I said I swapped the filter already, but it’s still doing the hesitation in hot weather. I hooked up the fuel pressure gauge on it now that I got it to replicate, idle is at 30 and snapping the throttle open brings it down to 15-20 . I’ll be throwing in a fuel pump here pretty quick since I don’t want to melt the head gasket or some stupid stuff. Thanks for the help everyone, I’ll post results once the pump is replaced to hopefully help someone else with the same issue

 

[berniemac73]

So I wanted to let you guys know, I don’t know if I said I swapped the filter already, but it’s still doing the hesitation in hot weather. I hooked up the fuel pressure gauge on it now that I got it to replicate, idle is at 30 and snapping the throttle open brings it down to 15-20 . I’ll be throwing in a fuel pump here pretty quick since I don’t want to melt the head gasket or some stupid stuff. Thanks for the help everyone, I’ll post results once the pump is replaced to hopefully help someone else with the same issue

Intake air temp or maf can effect "hot ambient" running temps.

 

[99Ebauer]

Intake air temp or maf can effect "hot ambient" running temps.

With my little scanner hooked up, it ran better with idle air temps at 180 F than it did at 120F right off the freeway. This Vegas heat is bruuutal. No drop offs with air temp or mass air flow sensor. Same with the throttle positioning sensor. I did swap the MAF and the TPS with the ones on my 2000 Ranger. Still was doing it.

 

[99Ebauer]

Alright so after putting in the fuel pump, used a Delphi full module. Idle is at 63 PSI. Snapping throttle open goes up to about 65. And holds pressure even after 30 minutes of letting it sit with the engine off. Took it for a 50 mile test drive in the 111 degree heat today. Freeway, surface street, and drive through driving and it didn’t hiccup once!! It was that damn fuel pump. It was original, the date was from 6/99. Thanks everyone for the help. Hopefully I won’t be back for more troubles lol.