I have a 1986 Ranger with a 2.9 v6, 5speed, and 2wd. (131K) It acts very strange, When I start it up and go it runs great for about 45 sec/1 mile. Then it starts to run real bad for a little while. It chugs real bad, sounds real weird in the exhaust(no muffler, get to that when it runs good), little pops here and there, very little power but still goes. Then after a few minutes it starts to run better. No shuddering unless I give it more than 1/2 throttle, and the weird popping noises dissapear. It will continue to run like this until I shut it off, then it repeats the cycle when I turn it on again. Took it to a shop and they couldn't figure it out, replaced fuel filter, fuel pressure regulator, dist. cap and wires, spark plugs, and still does same thing. Any one else have same problem? Some one told me it may be the TPS sensor, (throttle positioning sensor). Where is this on the engine? Any help would be appreciated!!
Have you or your mechanic run the computer diagnostic tests? If not, that's where I'd start.
As for the TPS, it's a simple variable resistor that bolts to the throttle body opposite the throttle cable.
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'87 Bronco II XLT 4x4 & '92 Explorer XLT 4x4 & '98 Chev Suburban K1500 SLT 4x4
I've had the same problems with mine. (same engine, 20k miles less) but I've noticed it only happens when I don't warm it up for five or six minutes anytime it's been sitting more than five hours. Are you the "get in and go" type?
It only shudders a bit when it's been sitting less than four or five hours and the engine is still warm, so I only have to give it about a minute or two before I go.
I'd get the codes pulled, I think the TPS would show up there if its out of whack. Mine isn't and it still acts funny.
I have tried letting it warm up but that does not seem to help. It always runs perfect when I start it up, then runs real bad for a little while, then it runs okay for the rest of the time until I shut it off then restart it. It also seems to do better when it is a little bit cold. I think I have a problem with more than one sensor. The motor is in good shape, but it just gets confused. I will have the codes pulled when I get the money. The last shop I took it to apparently didn't do it. (It still runs bad!) And I paid them money!
Yeah, you have to be careful what shop you take it to. The last one I took mine to was a ripoff. "Nothing a couple gallons of gas and a match can't take care of" was the mechanic's diagnosis. :-(
Keep us posted.
Mine also seems to be better in cool (65 degrees or less) weather.
Do you have enough money for a paper clip and a cheap analog voltmeter (~$5) or test light? If so, pull the codes yourself (www.dalidesign.com/hbook/eectest.html).
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'87 Bronco II XLT 4x4 & '92 Explorer XLT 4x4 & '98 Chev Suburban K1500 SLT 4x4
Wow, thanks a lot mrshorty! I think I can handle those expenses, (In college and kinda broke). Ill try to do it when I get some free time. Thanx for the link.
