Fuel Pressure Regulator Problems?

[camREEtrDEE]

Hello all! So I have a 1993 Ford Explorer XLT, and I just replaced the fuel injectors. They were all gummed up and some of the nozzles were cracked. After getting them to line up (which was a pain) and seat into the manifold, I replaced the fuel plenum gasket, and upper intake manifold gasket, and I put everything back together. After triple checking the vacuum lines and torque on the manifold bolts, I fired her up. Much to my dismay it runs even WORSE than before. E.I it barely runs. It will smoothen out for about 30 seconds then go back to almost dying, and cycle back and forth. Giving it a small rev helps for a bit. Now I know the injectors are plugged in correctly, and they are all brand new injectors from RockAuto that have been tested thoroughly.

However when I was replacing the injectors, I took the vacuum line off the FPR, I noticed fuel leaking from it, as well as the fitting on the regulator being wet with fuel. From what I understand, this drains back into the engine to be burnt, at the cost of running rich.

TLDR; Would replacing the fuel injectors make an already failing FPR worse? Maybe due to increased demand?

 

[Turdle]

A fuel pressure gauge will tell for sure..

Cheap air gauge will get ya there, engine running .


First though. Fix the common mistake we all make when working on the sweet ol v6

Double check, then, triple check the firing order on the driver side of engine. I bet you have 2 spark plug wires cross connected

 

[camREEtrDEE]

A fuel pressure gauge will tell for sure..

Cheap air gauge will get ya there, engine running .


First though. Fix the common mistake we all make when working on the sweet ol v6

Double check, then, triple check the firing order on the driver side of engine. I bet you have 2 spark plug wires cross connected

I didn’t remove anything with the ignition system though. Maybe that was my mistake and it caused me to unknowingly pull on a plug wire too hard. In any case, the regulator diaphragm is leaking so it needs to be replaced anyways. I was just scratching my head as to why replacing the injectors seemed to aggravate the issue. It was drivable before. Now it’s definitely not. I had the fuel filter show up today since I planned on replacing it too.

 

[wollimann]

the regulator diaphragm is leaking so it needs to be replaced anyways.

If the FPR looks like this, i would change it.

 

[camREEtrDEE]

If the FPR looks like this, i would change it.
View attachment 466495

It is actually all dirty, and most likely the original. It only has 83k miles on it, but from what I understand there aren’t many of these first gen’s on the road with original regulators, reguardless of mileage. I’ll get a picture up soon. Just gotta wait till that next paycheck hits to replace it lol.

P.S. Those zip ties are holding the vacuum line on the FPR. It’s so slippery with fuel it wont stay on.

 

[410Fortune]

Any fuel on the vacuum side of the regulator means the vacuum regulator is bad

There should never be fuel in the vacuum line

You need to test fuel pressure if it acts up after replacing the fuel pressure regulator

The only way fuel gets to the vacuum side is if the diaphragm rips

 

[camREEtrDEE]

Any fuel on the vacuum side of the regulator means the vacuum regulator is bad

There should never be fuel in the vacuum line

You need to test fuel pressure if it acts up after replacing the fuel pressure regulator

The only way fuel gets to the vacuum side is if the diaphragm rips

On the list. lol. I have the lower manifold off right now since I have a coolant leak at the front drivers side, leaking down the block over the fitting for the oil pressure sensor and onto the ground. I could not for the life of me figure out where it was coming from. Sure enough, I take the lower manifold off and gasket around the front drivers side water jacket is split/cracked. I’m hoping thats the problem and not a head gasket lol.

 

[410Fortune]

Lower intake gaskets are known for this
Have a good look at your freeze plugs too they can leak water in that location

Sound Like you found it! I say it all the time, there is not a out 4.0
Put there that does not need intake gaskets they simply do not last 25+ years, especially not with ethenol fuel