1987 Jeep Wrangler Repair Question
1987 4.2 jeep pinging
I would also like to add that i have tried adjusting timing up or down even to extreme's but didnt help
you may have excessive carbon build up which will cause the ping. it may be an octane ping as well. try using some premium fuel to see if it goes away.
by the way, the kncok sensor is on the block. the sensor you are referring to is intake air temp sensor .
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Re set ignition timing to correct settings and try the premium fule as mentioned in last post.
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I thought aabout the carbon build up too ran a tank of chevron super and 2 bottles of chevron injector cleaner didnt help seemed to have happened all at once. just went out to see if i could find knock sensor on block couldnt find it but i did see that one bolt on the starter is loose and starter isnt sitting straight maybe im hearing that rattle. I was about to pull timing cover to see if jumped time but with wrench on crank pulley only has about 3 degrees slack in chain dont think it would be that (runs too good anyway to be that) thanks for making me look for knock sensor even though i didnt find it (maybe thats why parts stores dont list one for that year it dont have one) maybe timing didnt move after all when i tapped on intake i will put fan back on and tighten starter and go for test drive hope thats the problem already sank a lot of $$$ into this thing figures it would be something simple... it does crank fine though but at times you could hear something rattle underneath... i will let you know...mike
the kind of cleaning you need cannot be done by additives. it has to be done at a shop by a pro. it is a great service.
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I WAS NOT SURE WHAT YOU HAD FOR A DISTRIBUTOR
I LOOKED HERE
YOU HAVE, WHAT I "NOW" HAVE IN MY '77
MAYBE YOUR DISTRIBUTOR IS SCREWING UP
MAYBE THE MECHANICAL ADVANCE IS NOT WORKING, POSSIBLE BROKEN SPRING
IT COULD ALSO BE THAT THE VACUUM ADVANCE AIN'T-A-WORKIN'
BOTH OF THESE CAN EZily CHECKED W/ A TIMING LIGHT (NEVER EVEN LOOKING INTO THE BOTTOM OF THE DISTRIBUTOR...LESS YOU JUST WANT TO)
DO YOU KNOW HOW TO USE THE LIGHT TO TEST 'EM, OR DO YOU NEED SOME GUIDANCE?
ok im back sorry been at work. found a loose starter didnt help, found a vac diagram in chilton manual showed ported vac to vac switches hooked up in a different spot from hood sticker again didnt help actually worse. this being carbureted any cleaners would hit everything from carb, intake, valves, combustion chamber etc . the knock sensor is on the intake though it shows it the chilton man. i have to tap pretty hard on the intake right beside it to make it change timing maybe it is bad cant find one though. i will look some more today...mike
INFO ON THE VEHICLE SUPER-SECEDES ANY OTHER INFO YOU FIND
IS THIS ACTUAL "PINGING" YOU ARE HEARING, OR IS IT ROCKER ARM/ PUSH ROD RATTLE OR TAPPING YOU ARE EXPERIENCING?????????
it sure sounds like pinging you can deliberately make it make the noise by accelerating let off (or cruise) and it goes away sounds like a bag of marbles, im getting my hands on a lab scope this week and im going to check the signal coming from the knock sensor gonna take the hood off and leave scope hooked up and see if knock sensor hears anything while engine is pinging
DO YOU KNOW HOW TO CHECK YOUR 2 ADVANCES WITH A TIMING LIGHT---TO SEE IF THEY WORK AS THEY SHOULD?
IF NO, I CAN TALK YOU THRU IT, YOU NEED A DWELL/ TACH METER AND TIMING LIGHT....I SORTA GO OUT OF MY WAY TO TRY TO HELP ANOTHER JEEP....1 EXAMPLE BELOW OF HOW FAR (THIS IS NOT YOUR FIX)