greetings all-

i am working on my girlfriend's 1997 ranger. 1997 flareside, 2.3L, 5speed manual. 4x2. i really could use some help dignosing what is wrong. i am burning up boyfriend credibility with not being able to fix this. i have been a ford guy all my life. my last gasser was 1992 4L Explorer V-6. since then i have convered to diesel and have been running 7.3's since.

timing belt was done 2-3 months ago by a mechanic. truck ran fine afterwards. lately, mileage went down noticably and then the truck started to have a rough idle and when cold. CEL on. P0133 code. light went off after a tank of premium gas.

it is almost loping- revs up, slows down to a shudder, then revs up again and so on. when it warms up, it doesn;t lope, but idles really rough.

i have CarCode with the PWM dongle. i am not totaly proficient with it yet, but i am learning. i scanned for codes, i got


considering that the truck has 105k miles, it was time to do a full tune up. air filter was changed at last oil change. i changed plugs and wires (PITA), pcv and changed the oil. seeing the o2 sensor readings, i changed both O2 sensors. i traced all the vacuum lines per the sticker on the radiator support. all the boots at the connections looked good. pulled negative battery cable to reset the pcm.

changing these parts had no effect. running the truck with the heat and a/c off, it still idled rough. when i turned on the a/c the rpms increased, and was more steady, so i figured it might be the IAC.

i pulled the battery negative to reset the computer and changed the IAC. after restarting, it still has rough idle.

i started spraying all the obvious places with carb cleaner trying to find if there was a vacuum leak somewhere that i missed. the only place that carb cleaner had any effect was the throttle shaft where it enters the intake plenum.

i checked the EGR, and it >looks< ok. i gave it a good coupple of whaks in case it was stuck. i do not know how to check it. if there are any checks, could someone point me to the a rightup?

No codes show now. Since i reset the codes earlier in the process, i figured it would throw new codes. i have not take then thing for a hard drive to try and force a code.

the CarCode's Data section everything passed except for
"$03 Fuel System 1 and 2 Status was System 1 Open loop due to detected system Fault"
i don;t know what to think of that.

and from the Test Section-
"$10 CATRAT2 Catalyst Rear to Front Switch Ratio Bank 2 is 1023.98 to 1 with a maximum limit of 0.08 has failed. "
since the 2.3 only had one bank right? this line seems erroneous.

i looked for the intake manifold bolts thinking i might give them a snug, but could not physically see them. i could not get underneath to spray carb cleaner under there. i am really starting to think that the intake gasket might be suspect, but i can not hear anything.

i am looking for the timing specs on ths motor to make sure that the timing belt was put on right. while working on it, i saw signs of not the best workmanship. cracked fan shroud, pair of vice grips on the broken negative terminal.

i can forward the CarCode scans if anyone has it to look at.

can anyone help diagnose this? what did i forget?

dennis
chicago

 

Sounds like the oxygen sensor(s) are bad. Therefore causing the truck to attempt correct, and thus producing a gas-sucking power loss. '97 is old enough it's prolly about time for the 02's to go anyways.

That being said I skimmed this, time crunch sorry, so I may have missed something. Somebody else won't though! Just something to consider.

 

i did change both O2 sensors as part of round 1.
thinking of rechecking timing.
how do we check vacuum on these things?
dennis

 

My lean code stemmed from a bad intake manifold gasket (the one between the head and the lower intake). It wasn't too bad of a job on my 2000 2.5L 5sp. The carb cleaner trick helped isolate the problem. Also, see if you can look at the fuel trims with a scanner. If the long term fuel trim is high, then it is most likely a vaccum leak. My gasket was broken on the ends (cyl 1 and 4). Might want to clean the MAF sensor while you are at it. Good luck.

 

Checking the vacuum: Get a vacuum gauge and hook it up to one of the extra lines on the rear of the intake manifold.

Rechecking timing would probably be a good idea.