Weird idle issue with motor wanting to stall

[NavyVet88]

2002 Ford Ranger Edge 3.0L 80k


I was idling at my local zaxbys drive through getting dinner for the wife and I earlier and the truck just started acting like it wanted to stall all of a sudden for about 15 seconds and then it recovered on its own. It then drove perfectly fine with multiple intersection stops and stops signs before I got home about eight miles down the road. My train of thought On this is fuel related. It still has the original fuel pump and all the parts listed below were replaced with OEM except the fuel filter which is duralast brand.

In the last year and a half, I have replaced the plugs, coil pack, plug wires, MAF, TPS and IAC and fuel filter as they were factory parts that were nearly 20 years old when I bought the truck last year. The original MAF and IAC were replaced most recently due to becoming faulty.

I suspect the fuel pump is about to surprise me at the most in opportune time that it can. Is there anything I can do to determine if it's the fuel pump at this point?

 

[JimPghPA]

Is the oil warning light working? If not, it could be low oil pressure because of a failing oil pump. When they go bad the first sign is poor idle because it is at low RPM that the can not supply enough pressure.

 

[oldhp]

Other than putting a fuel pressure gauge on it, nope. No codes? It takes about 3 hrs to replace. Pull the bed off, much, much easier to do. Have helped with 2 of them.

 

[NavyVet88]

Originally Posted by JimPghPA
Is the oil warning light working? If not, it could be low oil pressure because of a failing oil pump. When they go bad the first sign is poor idle because it is at low RPM that the can not supply enough pressure.


No oil light. I forgot to mention also that I did replace the cam shaft synchronizer about a year ago too.

 

[NavyVet88]

And no codes of course.

 

[eljefino]

Look for gas in the vacuum line to the fuel pressure regulator.

 

[Lubener]

Originally Posted by NavyVet88
2002 Ford Ranger Edge 3.0L 80k


I was idling at my local zaxbys drive through getting dinner for the wife and I earlier and the truck just started acting like it wanted to stall all of a sudden for about 15 seconds and then it recovered on its own. It then drove perfectly fine with multiple intersection stops and stops signs before I got home about eight miles down the road. My train of thought On this is fuel related. It still has the original fuel pump and all the parts listed below were replaced with OEM except the fuel filter which is duralast brand.

In the last year and a half, I have replaced the plugs, coil pack, plug wires, MAF, TPS and IAC and fuel filter as they were factory parts that were nearly 20 years old when I bought the truck last year. The original MAF and IAC were replaced most recently due to becoming faulty.

I suspect the fuel pump is about to surprise me at the most in opportune time that it can. Is there anything I can do to determine if it's the fuel pump at this point?


Check the fuel pressure.

 

[andyd]

Originally Posted by eljefino
Look for gas in the vacuum line to the fuel pressure regulator.



X2

 

[Falkirk88]

There are two things that can happen with the Fuel Pressure Regulator. One being that the diaphragm splits and allows fuel to be sucked into the intake creating a rich condition. Another issue is if the regulator does not open. This will cause a spike in fuel pressure and push more fuel through the injectors.

Hook a fuel pressure gauge to the engine and run through all of the tests, KOEO, Static Leak, KOER, and so forth. Go drive the truck with the fuel gauge available to read and see if you get spikes. I had one that did this on a Ford F250 with a 5.8L. Replaced the regulator and all was good again.

 

[NavyVet88]

Thanks guys I appreciate it!

The issue hasn't happened again to this point but I will monitor it.