4.0 Power problems

[rattlinram330]

I recently got a ranger, it has something wrong with it. It is a 94 4x4 super cab 5 speed. It lacks power and kinda sputters most of the time. Sometimes if I press the pedal to the floor it will quit sputtering and take of correctly. What could be the issue? I have changed the spark plugs, wires, air filter, and cleaned mass air sensor.Also the check engine light comes on and off?

 

[97ranger4x4]

Does the check engine light blink? Or just go on and off periodically?

If you can get it to an autozone, or other parts store with the check engine light (CEL) on, they will most likely read it for free. I just realized you have a 94 so it will be an OBD 1 truck. Try to get the code or codes for your CEL. Post them up here so we can try to help you out.

Also did you make sure you set the spacing on your plugs to specs?

Does this happen under any condition or all the time (ie, when its cold, or hot)

ohh BTW, welcome to TRS!

Keith

 

[rangerbert]

Have you changed the fuel filter, PCV valve

 

[Kona]

Check the vacuum lines

 

[rattlinram330]

It happens all the time. The light comes on for a while then goes off for a while. My plugs are correct. It was doing this before I changed them. My autozone here does not have the OBD1 attachment for there scanner.
I will change the filter and pcv.

 

[rattlinram330]

Codes say it is running rich (you can smell it) and something with egr, and maf.?

 

[rattlinram330]

ok I have replaced maf and coolant temp now the only codes are 172 and 177 i believe this would be a o2 sensor problem? Help me here please before I continue to hemmorage money. Thanks

 

[Earl43P]

http://www.therangerstation.com/tech_library/3digitcodes.html

It isn't necessarily the O2 sensor. It could be a vaccum leak from your description.

However, you could convince yourself that the O2 sensor is bad, simply because it runs good at WOT. WOT puts the PCM back into open loop, ignoring all the emissions sensors and running on its pre-programmed default for full throttle.

I don't know if your year was prone to intake gasket failures, but that is a common source of 4.0 vaccum leaks. Try spraying carb cleaner around the intake mating surfaces (on the engine side of the throttle body, not the intake tube, but you should check it for leaks too) and see if the idle changes. If so, replace the gasket.

Don't neglect the PCV valve tube, it can leak too.

Do you have any other symptoms, like the heater/vent air gets directed to Windshield Defrost when you drive? Again, that's a vaccum leak.

 

[btbwinbuck]

Howdy

Hows it going new to this site. Just wondring if you ever got your problem fixed with your ranger. I'm having the exact same issue with mine to a tee. Hopefully you have some advice.

 

[rattlinram330]

no I have not got it fixed yet. I have changed the O2 Sensors .......not it either. I am still working on it. Is yours the original motor? Mine isnt and I am starting to wonder if my motor is a Cali. and my truck (computer) is a Fed.?

Also I do not have an issue with air and defrost and I checked it for vac leaks nothing. I do have a little oil around #5 though?

 

[rattlinram330]

Codes ar now 172,173,177,178? It also back fires a little. and the temp gauge is above halfway. Help me someone

 

[SoLongStang9499]

How does your oil look? Have you been losing coolant over time? You may be mistaking the smell of burning coolant rather than rich, they can smell similar. If so check your intake manifold bolts and if that doesnt do it it may need to be disassembled.

 

[mlunsford]

Let it sit for a couple of days. Disconnext the wiring harness from the coilpack. Crank it over after sitting. pull the plugs. Check plugs for water/fuel. You can light the plug if does not burn it is water = cracked head(s). Buy new heads.

 

[eric17]

Let it sit for a couple of days. Disconnext the wiring harness from the coilpack. Crank it over after sitting. pull the plugs. Check plugs for water/fuel. You can light the plug if does not burn it is water = cracked head(s). Buy new heads.

what?

first try some simple things, check your fuel pressure at the rail with a guage, and also id really really look into the fuel pressure regulator, a few month ago before i replaced my tranny mine was doing this, id be rolling along just fine but if i slowly stepped into it, it would miss and run like shit, even sometimes from a dead stop and especially when it was first started cold, first time it ended up being a vac leak by the fpr, this time i think the fpr went tits up, good luck to you.

 

[woodyedmiston]

You can always try the tried and true - if dangerous - trick of spraying Berryman's around areas that leak - where the intake mates to the manifold, etc. If you have that kind of leak the engine will catch up for a second when you spray fuel around the vacuum leak. Wear eye protection and keep a fire extinquisher handy.