gonna see if anyone can help

[89 ranger.]

Soo i am new here but have had my truck for sometime.. heres the deal and its a doozy.

Trucks starts and runs perfect cept you know the typical 2.9L tick.. besides the point anyways.. if I go into the store for about 20 minutes of so (before 10 minutes and after 35 minutes it doesnt do it or if it does its not as bad) and come back out and start it the truck runs rough like I have a huge cam, it lobes then with little time or a couple pumps of the gas it clears up..

I thought maybe voltage problem because because when I at a stop and my heater is on, headlights, other accessories (nothing truck shouldnt handle) the voltage drops down to under twelve and close to the mark above the 8. I replaced the battery, alternator (VR was shot), new battery cables,

no one has ever been able to solve this not even ford, its really annoying and quiet embarressing,

I am thinkin maybe leaky injector flooding cylinder, crappy coil, ignition module??, or maybe something with speed density sensors.

please helpp

done a ton of research nothing,

someone below me posted something similar but they never posted a solution

thanks for reading my novel

 

[just truckn]

89 ranger i have the same damm problem with my heep had a mech check it he put a charging test on it and it was charging at 14.2 still no solution on that just like the rest of the problems nobody can figure out .

 

[jamie18]

I had the same problem and replace tps with no solution and I finally got a code for the oxygen sensor after about six months. replaced o2 sensor and has run fine ever sense, hope this helps.

 

[89 ranger.]

I have replced the O2sensor. TFI? Maybe

 

[IMenriched]

Has any of you ran codes? and what were they?

got to wonder if the MAP sensor is goofy

 

[89 ranger.]

I have not run codes.. Check engine light isn't on will codes stilll show?

 

[89 ranger.]

Did read the TFI on these can cause weird problems like this and hard to diagnose

 

[IMenriched]

Did read the TFI on these can cause weird problems like this and hard to diagnose

yes they can, so can several other sensors, like a fore mentioned O2 sensor. Or it can be a simple bad connection or bad ground.

I have not run codes.. Check engine light isn't on will codes stilll show?

Just because the CEL isn't lit doesn't mean codes are not present.
although older OBD 1 systems , like your 89', were better about giving hints often times they don't lite. or a previous owner may have taken out the bulb.

 

[89 ranger.]

Bulb is there. Put new ground wires in. New o2 recently.. Don't know wat else to do

 

[dawson111299]

my ranger does the same thing allthough i havnt really paid much attention to it as i attribute it to the fact that some of my smaller plastic vaccum lines are broken and pluged off and i just havnt gotten around to fixin em yet. sound like the ecm is searching for some sensor input and is just tring to find the correct fuel air mix to run at so when it cant it reverts to a factory default. The whole voltage thing is a symtom of low idle I could be wrong but thats just what i thiink is wrong with mine .

 

[IMenriched]

Bulb is there. Put new ground wires in. New o2 recently.. Don't know wat else to do

get your codes.....http://www.therangerstation.com/tech_library/OBD_I.html

which ground wires were looked at or replaced?

If no codes come back....then check the Fuel Pressure tests it in the situation that gives you most grief. Half warm state.

 

[89 ranger.]

I replaced the ground battery from the battery to the frame and from the frame to the motor. I cleaned both areas before reconnecting the grounds. i need a code reader and a code book or Ill just do it and let you know codes if any reveal themselves.

And to dawson111299 the voltage does change with the idle.. its better when the truck is in park actually its perfect.. but I have adjusted the idle and everytime it goes back down i dont know if the screw is moving or what... but its the fact that the needle twitches with the blinker and windsheild wipers but i will try again to turn the idle up..

 

[dawson111299]

Has any of you ran codes? and what were they?

got to wonder if the MAP sensor is goofy

come the think of it the vac line that goes to my map sensor is busted and plugged off Im gonna go to the pull a part junk yard and see if i can find all the new vac lines to replace them. I dont get a cel and i know it works. Gotta love those hard plastic vac lines Ive had 3 different rangers and every one of them had probs with them. Theyre so hard to diagnose because they are so small and 75 percent of the line runs through plastic conduit.
MAP (Manafold Absolute Pressure) makes sense to me. Im gettin those lines later today Ill repost after I do.

 

[89 ranger.]

Okay.. Did u replace any of ur vac lines? Also where on the motor is the map sensor. Somewhere on the intake manifold? I lost my chiltons so I have no idea..

 

[dawson111299]

replaced vac lines today unhooked bat while I did it to clear any codes that may have been set . drove around town for a while idle never changes now always steady seems to be a bit more responsive in the throttle to . Map on my 86 super is on the passanger side on the inner fender where all the relays are at. there is one plastic vacuum line about 3/8 diam and a 2 wires going to it kind of a flat rectangular box. also repaird the 2 small red and green vac lines that were cracked not sure right off hand what they r for but they were cracked and sucking air.