no start intermitant spark
03-31-2011, 12:08 PM
#1
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Year: 1990
Model: Cherokee
Engine: 4.0
no start intermitant spark
new porblem...90 xj 4.0...cranks, fires once in a while, has weak spark then no spark then good spark and tries to start then no spark again. tested cps...replaced cps...fuel pressure ok...i read about testing cam sensor but im lost. i know my slave cylinder is leaking and the old cps had oil all over it. if its dirty on the part the cps reads on (the flywheel i assume) will it give it a bad signal and keep it from strarting? im almost done with these peices of crap. i have 2 xjs that i have owned for about 2 months and i havnt had a problem free week yet. the best i got was 3 days. thanks
03-31-2011, 03:05 PM
#2
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Year: 1990
Model: Cherokee
Engine: 4.0
the old cps read 194 ohms, as does the new one and the one in my running xj. i checked as it was cranking with my meter on vac as it said to do and i read .2... so did the one i took out and the one in my running xj.... the testing procedure says replace if lower than .5 but i have one reading .2 and it still runs....please help! im tired of working on this! im going to just swap parts off of my running xj till i find the issue or til neither work and then im pushing them both into the lake! just kidding! i am desperate to get this fixed
03-31-2011, 03:10 PM
#3
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Year: 1998
Model: Cherokee
Engine: 4.0 rebuilt w/ bored TB, banks header, upgraded ignition, 3 row rad, high flow h2o pump, 180* t-stat
CPS controls fuel injector pulse, Distributor has cam sensor that controls ignition timing...
Have you checked coil also?
Have you checked coil also?
03-31-2011, 03:26 PM
#4
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Year: 1990
Model: Cherokee
Engine: 4.0
i just traded coils (coil from running xj into nonrunning...coil from nonrunning into running) no chnge. im gonna trade dist. now
03-31-2011, 04:37 PM
#6
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Year: 1990
Model: Cherokee
Engine: 4.0
ive looked through those pages and i did all those test but no luck! i changed the ecm and no change to the nonrunning but now the running one isnt running well. backfiring missing and so on! off to the lake with them!
03-31-2011, 08:02 PM
#7
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Year: 1990
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ok so im an idiot! i did not bolt the coil back down on the running xj so its running fine again! now the bigggest bonehead move! i completely passed over the spark plugs as the issue!! i cant believe i went through 2 days of diagnostics and it was $12 worth of spark plugs!!! no wonder everything i checked wasfine! thanks to the guys who helped out! i forgot to keep it simple!
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