Hello to you all, I live in the midle of the Atlantic Ocean, in Terceira Island in Azores and I have a 1997 Ford Ranger XLT 4x4 with a 4.0 V6 that at idle, it works just fine. No problems even if you push the gas peddle to the floor. However, when you are driving, it bogs like it is being starved for fuel. The OBDII reader said it was the MAF sensor so we put a new one, and a new fuel filter just in case. No more codes on the OBDII reader but it still behaves the same.

Any ideas?

I also have a 1988 Ford Ranger XLT 4x4 with a 2.9 V6 that it's kiling me with problems, but thats another story...

And I also have a 1987 Ford Ranger 4x2 2.3 that works great

 

1997 Ranger still has the Fuel Pressure Regulator(FPR) and return line to the fuel tank.
The FPR is on the fuel rail, it has a vacuum line attached.
Remove vacuum line and check it for gas smell or gas, if found replace FPR.

Does it idle at 700rpms when warmed up?

What is the exhaust pressure like?
When you rev the engine does the exhaust pressure at the tail pipe match the RPM, a partially clogged exhaust can cause bogging.

EGR valve opening early can cause bogging.

If possible use a vacuum gauge on the intake, it can tell you alot about engine condition.
i.e. vacuum leaks, clogged exhaust, rings, valves, ect......
Read here:
Technical Articles: Engine testing with a Vacuum Gauge - at Greg's Engine & Machine

 

Thank you for all the help...
- I've removed the vacuum line from the FPR and there's no gas smell or gas in it...
- It does 700 rpms at idle when warmed up...
- Then there's the EGR valve... can I eliminate it??? the "mushroom" on it is damaged could that be the problem???
- The exhaust pressure does look ok... doesn't look clogged...

I'll tray to find a new EGR valve... and also going to tray to find a Vacuum Gouge...
My biggest problem is being in the middle of the Ocean (there are no parts for sale)t

Thank you again.

 

EGR valve being open at the wrong time will cause poor performance.

You can eliminate it but will get a Check Engine Light(CEL) on all the time.

If idle is OK, not stumbling, then pull off vacuum hose from EGR valve and plug the hose with a bolt/screw of the correct size, that will prevent the EGR valve from opening, you will get a CEL, but see if it drives better.

 

It drives mutch better now with out the EGR valve, but it still "boogs" I'll try to remove the exhaust pipe and mufler to see if it's clogged...

Thanks

 

If you can get your hands on a Vacuum gauge it can tell you many things about the engine, including if the exhaust flow is limited.

Good read here about vacuum gauge testing and results:
Technical Articles: Engine testing with a Vacuum Gauge - at Greg's Engine & Machine