I got a 1987 Ranger that really acts up and is extremely hard on gas. When acting up it just pours black smoke from the exhaust, I think it's overfuelling.
I have put the folowing parts on this year and still can't figure it out.

cap, rotor, plugs and wires
O2 sensor (twice)
pressure regulator
TPS
MAP
temp sensor

I've also checked all vacumm lines and ground connections.
Any thoughts would be helpfull.

 

sounds like your injectors/needle is sticking open. yea i would bet that you are getting waaaay too much fuel dumped into it. check out your injectors with a noid light to see if they are even working Ohm them out to see if any are greatly different than the others

 

When checking vacuum lines, was there any gas in the line to the fuel pressure regulator (gas in vacuum line=bad FPR).

 

Does this have a transmission or is it an automatic? If automatic, check the vacuum line from the modulator for ATF. Have you checked fuel pressure with a gauge? Does it hold steady or leak down?

 

go to the wrecker and get an EGR and EGR controler and see if that works. mine was doing the same and that fixed it. carefull you don't brake the aluminum housing when undoing the EGR bolts.

 

ibugsy...if you figure it out, please post it here, cause mine is doing the same exact thing! I'm completely stumped. A guy I work with told me to try the "either" test, by spraying either around the motor while running to see if there's a vacuum leak. I changed all the parts you did, still running like crap. Maybe it's electrical? No check engine light either...

 

What year 2.9 do you have? '87 and earlier don't have a functional check engine light to light up (unless one has been added after the fact). If yours falls into that category, there's no check engine light to light up. In that case you need to run the EEC-IV self-tests to get any trouble codes out. Easy enough to do with a paper clip and a cheap voltmeter. See www.dalidesign.com/hbook/eectest.html or www.fordfuelinjection.com (this latter link doesn't detail how to perform the KOER test, though).

 

mrshorty, it's an '88, gonna give 87 XLT's idea a shot tomorrow...

 

87 XLT you are "the man" !!!! after a quick trip for another vacuum line, the ranger's up and running again! Kind of hard to believe that was it, Thanks alot !!!

 

Not sure exactly what you did, but i'm glad to hear that it worked. Thanks for the update.

 

The vacuum line running down to the tranny is metal around the exhaust, and I think the heat sheild above the cat. conv. rubbed a hole in it...hence vacuum leak. I replaced the whole line all the way down, runs like a top now...Happy as heck now, that darn thing had me stumped me for 2 weeks, and it ran horrible. Drove it back and forth to work today,(30 miles), ran like an almost-new truck!

 

I was wondering what you did & now I know. Thanks