89 still wont start
#1
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Year: 1989
Model: Cherokee
Engine: 4.0
89 still wont start
just replaced the cps and still wont start.replaced it with a napa one and the voltage is lower than my original.Why is the napa part soooo much better the any other box store?i dont see it, anyway im gonna try and drill thetop hole to increase voltage. Does it work better when its closer?by the way my old part was between 4.5 to 3.5 now it goes from 3.5 to 2.5
#2
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I sense some disappointment.
But, you kinda barge in here throwing it on the plate...Happy to help but, please, share some more info with us here if you will. The voltage is somewhat low, yes. Could also be a faulty NAPA CPS.
But, what made you decide the CPS was to be replaced in the first place?
But, you kinda barge in here throwing it on the plate...Happy to help but, please, share some more info with us here if you will. The voltage is somewhat low, yes. Could also be a faulty NAPA CPS.
But, what made you decide the CPS was to be replaced in the first place?
#3
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
just replaced the cps and still wont start.replaced it with a napa one and the voltage is lower than my original.Why is the napa part soooo much better the any other box store?i dont see it, anyway im gonna try and drill thetop hole to increase voltage. Does it work better when its closer?by the way my old part was between 4.5 to 3.5 now it goes from 3.5 to 2.5
#5
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
#7
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Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Huh...So, unplugged, probing directly the two leads to the CPS, cranking, you are seeing well over .35 AC volts, but you have no spark. I came up with a way to test the ECU signal to the ICM with an LED bulb. I did it successfully with a bulb from a Key-chain light from the $1 store, but soon the bulb failed.
So it's your rear Yellow wire. It should show 5 Volts. (the front Yellow should be more like 12). An led is polarety sensitive, (just won't work backwards) but if you connect positive to the 5V ECU feed, and ground the other end you should see it flash. If it flashes you are good to there! Problem is if it doesn't Idk what to say...(the bulb might have failed... ) I have a bunch that I bought off Ebay and can repeat the experiment. See here>
I'm still working out a better "presentation" but that's a start.. Thinking that if the black is grounding well, the front Yellow has 12V, the LED flashes and it's not sparking, that narrows it down to the ICM or the Coil.
So it's your rear Yellow wire. It should show 5 Volts. (the front Yellow should be more like 12). An led is polarety sensitive, (just won't work backwards) but if you connect positive to the 5V ECU feed, and ground the other end you should see it flash. If it flashes you are good to there! Problem is if it doesn't Idk what to say...(the bulb might have failed... ) I have a bunch that I bought off Ebay and can repeat the experiment. See here>
I'm still working out a better "presentation" but that's a start.. Thinking that if the black is grounding well, the front Yellow has 12V, the LED flashes and it's not sparking, that narrows it down to the ICM or the Coil.
Last edited by DFlintstone; 06-28-2014 at 07:54 PM.
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#8
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Year: 1994
Model: Cherokee
Engine: 4.0l
Check all your fusible links at the starter relay. Just fixed mine, several of the fusible links were bad and one fell apart in my hand. Best way I found to check them is to back probe them, doesn't matter whether the key is on or not, they get constant 12v from the battery post on the starter relay. I replaced mine with inline blade style fuses that are water proof.
#10
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Year: 1989
Model: Cherokee
Engine: 4.0
i would google back probing but no longer going to use google because of there stance on gun ads.so i will yahoo it.
#13
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Year: 90,84
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If the LED is flashing, the front yellow has 12 Volts and the black ground is well grounded, (an ohm or so resistance), likely you have a bad connection somewhere (ICU>coil contacts), a bad coil, or a bad ICM, in that order. I'm really reluctant to ever tell anyone to buy anything, but you may have narrowed it down.
All I'll say on coil resistance...there should be little resistance between the 12V (primary) terminals. Then there should be allot of resistance between there and the output, secondary, coil wire. It would be sweet if you could borrow/swap in a coil to see.
All I'll say on coil resistance...there should be little resistance between the 12V (primary) terminals. Then there should be allot of resistance between there and the output, secondary, coil wire. It would be sweet if you could borrow/swap in a coil to see.
#15
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Year: 1989
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i tested the coil to a new one,same readings on both,and tested the icm at oriellys and it passed so thats why im thinking something else is wrong