97 xj6 4.0 crank no start no spark
#1
97 xj6 4.0 crank no start no spark
My first post. Please soneone help me having issues with a 97 xj6 4.0 i bought yesterday. Was a no start from the door but i got it for 300 bucks so i didnt really care what it is. I charged up the battery and cranked it and it actually ran very rough for about 2 mins . I then scanned it and got code p1775. i seem to be intermittently getting no spark and hav replaced the crank sensor so far. I hate throwin parts at shitt for no reason but i was sure that was the issue. Now i get no starts at all and no spark. I am getting cranking rpms on the dash and the new crank sensor is ohm in spec. Although i am only getting 2.7 volts at the ckp sensor circuit. Could this be a bad ecm?! I already swapped relays . Please somebody point me in the right direction.
#2
Watch the volt meter that it does not drop below 11.4 volts during starter rotation
Below this voltage the starter will rotate the engine but be below the voltage to properly run the ECU / spark
The instrument gauge is very accurate
There are 2 relays that power up different sections of the ECU , on is the small one on the corner of the RH engine fuse box you can swap with the LH engine fuse box ( LH is really just the horn relay )
The second large relay is the ECU controlled relay called the X that is enabled by the ECU to bring power back into the other section of the ECU
To bypass the CKPS and ECU control of the # 1 fuel pump relay you can jumper
Last edited by Lady Penelope; 02-16-2019 at 04:39 PM. Reason: point the starter will rotate the engine
#3
#4
See page 50 then back to 49 for the wring out page on the CKPS
Black 23 and Black 26 does not get a reference voltage from the ECU
http://www.jagrepair.com/images/Auto.../jagxj1997.pdf
As you saw your fundimental reading on the inductance CKPS is 1300 ohms , the funtional reading is a sine wave with a frequency dependent on RPM
The Camshaft position sensor ( CMPS )s a 3 wire hall effect sensor that by design is not needed to start engine
It has a basic power source and not a reference voltage source
My computer was going nuts last night so let me clean up the last nights post while shoveling driveway
Black 23 and Black 26 does not get a reference voltage from the ECU
http://www.jagrepair.com/images/Auto.../jagxj1997.pdf
As you saw your fundimental reading on the inductance CKPS is 1300 ohms , the funtional reading is a sine wave with a frequency dependent on RPM
The Camshaft position sensor ( CMPS )s a 3 wire hall effect sensor that by design is not needed to start engine
It has a basic power source and not a reference voltage source
My computer was going nuts last night so let me clean up the last nights post while shoveling driveway
Last edited by Lady Penelope; 02-16-2019 at 09:54 AM.
#6
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