91 no power, bad mileage

[Mickey]

recently bought a 91 xlt. was getting over 300 miles per tank, all of a sudden less than 120 per tank and loss of power. generally no power uphill, pedal all the way down to go 35 mph. Engine light comes on but goes off and sometimes power seems fine uphill. Replaced fuel filter and the only oxygen sensor I could find. Auto zone said 2 but I only found 1. Never towed anything, did run out of gas and that seems to be when trouble started, when I replaced fuel filter I used compressor to blow back though the line to clear strainer as suggested by mechanic. Any ideas?

 

[jimbo74]

have you tried the maf?

welcome to the site... do a search fro the maf.... are you sure the 02 sensor was replaced properly? the light should come on anymore if you changed it however it may have a "hard" code left in it...

 

[MrShorty]

'91 an '92 Explorers only have one O2 sensor; Autozone's computer is "confusing" your '91 with later Explorers that did have 2 O2 sensors.
Since you ran it out of gas, I wonder if your fuel pump has developed a problem so that it can't keep up with the engine's demand for fuel. Check fuel pressure. When the CEL comes on, it might leave a code in the computer's memory -- run self-tests. Only requires a jumper wire (see www.dalidesign.com/hbook/eectest.html for directions)

 

[Mickey]

what is maf? I replaced o2 sensor myself, so no not sure it was done properly will do self test tomorrow, dont have lighted tester. Thanks

 

[jimbo74]

it is the mas air flow sensor.... located on the air filter box... check out www.explorer4x4.com for cleaning instructions under tips....

 

[Jimbo]

Check your Air Filter.

happened to be plenty of times...