Hey everybody. This is my first post so please bear with me. I have an 87 ranger that has started having problems over the last week or so. I had a similar problem a year or so ago. I put a new fuel pressure regulator on and it fixed it. So it started acting up again so I got another regulator and it didn't help at all. It won't idle at all without dying. The motor revs up then cuts out completly and dies. It's like I'm repeatedly pressing the gas pedal when I do get it to idle but I'm not touching it at all. It runs fairly well on the road until I let off the gas then it goes to shaking and jumping up and down till I get back on the gas. A guy told me to unplug a little cigarette pack shaped plastic box and see if it changed anything. I think he called it a map sensor? But that didn't do anything. I was thinking maybe the fuel filter was clogged up but I don't really know. It is fuel injected 2.9 4x4 regular cab. About 110000 miles. Not sure if filter has ever been changed. It doesn't smoke or smell like gas so I'm thinking it's starving for fuel. Does anyone have any experience or ideas? Any and all advice will be greatly appreciated and thank you in advance

 

Google Inova 3145 + amazon & read the owners reviews. Spend a couple of minutes testing with the Inova & theres a very good chance it will tell you what the problem is.
If this was an 88 you could pull the trouble codes with the CEL/check engine light, but your 87 does not have a CEL on the dash.

If you get an 11 code "system pass" you need to take a couple of minutes to test fuel pressure, Harbor freight will sell you the fuel injection pressure gauge for 20 bucks. Checking fuel pressure is VERY simple. Screw the gauge onto the schrader valve & start it up.

If fuel pressure is at 40 PSI & holds steady for 10 minutes with the engine turned off you need to test with a vacuum gauge to see if theres a mechanical problem with the engine. This is also some very simple testing.

You mentioned the MAP, if it's bad the Inova 3145 will give you a code 22 "MAP sensor signal voltage out of specification."