I am a new member to the site and to my 1988 Ranger. I have had a 1995 Mustang in the past but that was completely better than the ranger. My ranger will crank and idle rough so I unplugged the MAP sensor and it helped a lot so I am in the process of purchasing a new one but the truck also will die when letting off on the clutch. The only way to keep the truck going is if you continuously press the clutch and feather the throttle until you get up to speed or rev the engine to 4,000rpms and slowly let out on the clutch which will of course burn the clutch out in a few weeks. I have found a leak in the vacuum lines and fixed that but many more are plugged so I have found a diagram and am also in the process of connecting those. I would like to know what is causing the truck to loose power when accelerating and driving. Also when you floor it the truck will die out unless you ease the rpms higher and higher.

 

Mine is doing the same thing! Did you ever come across a fix for this? It's almost like when you throttle down there's nothing to push the truck further. Also, has a very high idle at startup (1700-2000). Truck does the same thing when letting the clutch out.

 

Are there any stored CEL (check engine light) codes? If you don't have a code reader, most automotive parts stores or repair centers will read them for free.

One has to ask themselves why the vacuumn hoses were removed and plugged; I suspect a previous owner was simply too cheap to buy some replacement hose, so they got capped off. Now the ECU/PCM is missing some input or getting readings from various sensors that are causing it to set adjustments to the fuel pressure to the injectors, and this could be why the engine is running rough.

Like you plan to do, replace all the lines, remove the batteries ground, wait 15 minutes, then replace (clears the memory) then start the engine and see if you got any improvement.

 

i do not have a CEL, i will try to pull codes later this afternoon. also, i will try removing the battery ground and seeing what happens.