Big Problem

[Joe400]

hey guys well my trucks really giving me a problem today. 93 ranger 4.0 manual tranny 4x4

anyways, while i was waiting at a stop light my idle started to fluctuate wildly and it soon became so bad i had to two foot it all the way home or it would stall. The check engine light came on for the first time since i've owned it. (Obd1, and i only have a obdII tester)

also i get this nasty black smoke out the exhaust and i cant keep it at idle. It's sucking gas like crazy.

its my d/d so any help would be greatly appreciated

its got new plugs and wires, battery's good, acceleration is still good

thanks

joe

 

[RobbieD]

There's plenty of more experienced hands here, who will be throwing better suggestions your way, but the Fuel Pressure Regulator (FPR) comes to mind right away as my 2.9L had a similar problem one time. It's easy to check, too, by pulling the vacuum line from the FPR and looking for gas dripping out.

 

[MAKG]

While the FPR is a good place to look first, there are quite a few things that can F up the mixture. By all means check the FPR, and then run the self tests and probe the oxygen sensor(s). Inspect the spark plugs, because they aren't new anymore....

But be ready to get professional help if you EVER feel the need to guess, or jump to conclusions (e.g., a code by itself does not mean you should be buying any sensors, and "new" simply does not mean the same as "good"). Throwing parts at it is often considerably more expensive, VERY time consuming, and confusing.

And FYI an "OBD-I tester" is a paper clip.

 

[Joe400]

i'm leaning more towards 02 sensors, i tried an idle air, and tps sensor from a friends truck. nothing


where is the fuel pressure regulator?

 

[almostclueless]

On the fuel rail on the engine. vacuum operated thing, one side of the diaphragm inside it has almost 40PSI on it, the other side has vacuum. The moment the diaphragm starts to leak A LOT of fuel can get sucked into the engine, enough that I would change the oil if it's the problem.

 

[mudnsnow]

Check Coolant sensor

Check your temperature sensor(Top left front of engine, Light green-red and Grey-red Wire) Just unplug and take resistance of the sensor
59 000 Ohm @ 50 Farenheit
11 000 @ 122
2070 @ 212

Check the wiring between the sensor AND pcm for short/open

 

[Joe400]

well i decided after both o2 sensors looked good to just start unplugging sensors till it stopped stalling. To my suprise it was actually the mass air sensor causing it to stall. I threw a spare on, and it ran great

i've never had a mass air sensor just shit the bed out of the blue.. whatever


thanks again
joe

 

[RobbieD]

Glad to hear that you got it sorted out.

 

[predator]

thats what is happening to my explorer....except i just put a brand new maf sensor on it.....i wonder if it is just blowing maf sensors....