Check engine light flashes when I turn key - xj

Rwentz

Member
Joined
Mar 3, 2011
Location
Greensboro
I have a 93 jeep Cherokee and it hadn't ran in awhile, thought it was because I got my distributor wet but I'm thinking worse now. Timing sounds to be off when I try to crank it, it's getting no spark from the coil wire, can someone please tell me why the light flashes

Before I start going to buy parts I don't need and money I don't have. When I noticed this I just got scared I got my ecu wet, or body control module
 
Maybe you should back up and tell the story from the beginning. What happened when it quit running?
 
do you mean Check Engine light flashing, and no spark is going to be the crank sensor. unplug the crank sensor (on back of intake manifold at the rear going down to top of transmission bellhousing on drivers side of motor) leave it unplugged for couple minutes while battery unhooked and ECU unhooked. try that, if not call me and be happy to guide you through some tests to locate the problem before spending money on it. John 828-217-0730
 
88jeepster said:
do you mean Check Engine light flashing, and no spark is going to be the crank sensor. unplug the crank sensor (on back of intake manifold at the rear going down to top of transmission bellhousing on drivers side of motor) leave it unplugged for couple minutes while battery unhooked and ECU unhooked. try that, if not call me and be happy to guide you through some tests to locate the problem before spending money on it. John 828-217-0730
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Thank you for the help, idk why it didn't go to my alerts. But I am trying this now. I didn't unplug my ecu cause I didn't know where to start. Will it work if I just unhook negative terminal and cps connector?
 
unhook positive and negative cables...touch positive to ground for 3minutes (best done on A/C compressor bolts...then leave ECU and CPS sensor unplugged for few minutes or so and give that a try. if no luck there, check and make sure the negative ground cable going to back side of cylinder head (drivers rear) is not broken or melted on manifold cause that will cause ignition system to fail also. if all these are good, either do some ohm testing on the sensor or as cheap as it is, put a crank sensor in it anyways for only 30.00 bucks....nice to have that piece of mind working anyways.. hope this helps and works out for ya...that crank sensor is a pain when it leaves you stranded so I would replace it for as cheap as it is anyways trust me do it, save you a headache...need 11mm and 2ft or so extension or small hands with 11mm small wrench and go down the side of the intake works too
 
Well im going to try that... Just replaced the cps and nothing, just doing the same thing.
I have never had this much trouble working or diagnosing a car in my life! Why in the hell did jeep decide to use all these damn sensors?
 
Is this what your talking about negative ground? (Silver, skinny snake thing lol)
image.jpg
 
Did you test the coil like I said in your other post about the same subject?

Do you have fuel pressure and injector pulse? Do you have spark?

Do this to diagnose the ignition:
Unplug the 2 wire connector at the coil. Insert a paper clip (jumper wire) into the unplugged connector. Attach test light clip to the positive battery terminal. With the pointy end of the test light, probe the paper clip (jumper wire) while you are cranking the engine over. Observe if it flashes or not.
If it flashes- the PCM and crank sensor are good (coil is being grounded) and you have power present. This means the coil is no good
If it does not flash- either the ground side of the circuit is no good (crank sensor signal to pcm or pcm itself) or the ASD voltage is not present.
 
Jody Treadway said:
Did you test the coil like I said in your other post about the same subject?

Do you have fuel pressure and injector pulse? Do you have spark?

Do this to diagnose the ignition:
Unplug the 2 wire connector at the coil. Insert a paper clip (jumper wire) into the unplugged connector. Attach test light clip to the positive battery terminal. With the pointy end of the test light, probe the paper clip (jumper wire) while you are cranking the engine over. Observe if it flashes or not.
If it flashes- the PCM and crank sensor are good (coil is being grounded) and you have power present. This means the coil is no good
If it does not flash- either the ground side of the circuit is no good (crank sensor signal to pcm or pcm itself) or the ASD voltage is not present.
Click to expand...


Damn that almost makes sense...you are getting wiser in your old age.
 
any luck on the jeep yet, and yes that was the ground I was mentioning. sorry the cps didn't work for you but as I stated for the cheap price it's a great part to have new anyways. spray some ether or GAS in the TB and be done with it!!! it runs, fuel problem, it don't run spark problem and we can go from there. (easier than doing electrical testing)
 
Rwentz said:
Is this what your talking about negative ground? (Silver, skinny snake thing lol)View attachment 71033
Click to expand...
is it just me or is that cable frayed in half, if so theres your issue. only the older Cherokees have that issues where that ground strap is for the ignition system and such. don't quote me on your year model being that one but I know the renix and early 90s are.
 
Nah that cable ain't cut, it was the coil . And the very 1st thing I did was try starting fluid lol, but I did the testing above and picked up a coil.
 
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