my mj hates me... crank no spark

[bumpy]

i havent driven the dang thing in a year. i just replaced the coil, ignition control module, cap, rotor plugs and wires and it still won't start. its gettin gas but won't make a spark. I'm thinkin the CPS but not 100% sure... murrays has them for $45 good deal or not?

[LEAD_NOT_FOLLOW]

Check your CPS. I'd check it (takes 5 mins) before you replace it.

 

I have a link on GLXJ, but the server just went down so give me a few mins and I'll get it back up for you with the link.

[MiNi Beast]

http://members.cox.net/wilsond/Fixes/di ... CPSdetails

 

[ejndssn]

:agree: x3 faulty CPS is mostly the culprit. i always pic them as xtra's at the pic & pull and test them to ensure that i have a ready spare handy in case of an emergency get a new one first :brows:

[jtdesigns]

:agree: x3 faulty CPS is mostly the culprit. i always pic them as xtra's at the pic & pull and test them to ensure that i have a ready spare handy in case of an emergency get a new one first :brows:

 

 

How you test them?????

[HOrnbrod]

How you test them?????

 

Measure across the pickups with an ohmeter for the internal resistance of the CPS (200 ohms + or - 75 ohms). This test is not a 100% guarantee that the CPS is good, but that's about all you can do on a bench test. Most of the time CPS problems are caused by corrosion at the connector since the internal coil resistance is so small.

[MiNi Beast]

:agree: x3 faulty CPS is mostly the culprit. i always pic them as xtra's at the pic & pull and test them to ensure that i have a ready spare handy in case of an emergency get a new one first :brows:

 

 

How you test them?????

 

Read my post, you know that picture there, tells you how :nuts:

[jwilson25]

I think I'm going to join the club once I diagnose it for sure...mine died while backing it up yesterday and wouldn't restart. Also noticed it running worse and power was down when I moved it the day before. Sounds like it wants to catch every once and a while, but no joy. I can't find any evidence of the CPS ptach harness either, does anyone have the part number for that package, I can't seem to find it anywhere? :nuts:

[jtdesigns]

:agree: x3 faulty CPS is mostly the culprit. i always pic them as xtra's at the pic & pull and test them to ensure that i have a ready spare handy in case of an emergency get a new one first :brows:

 

 

How you test them?????

 

Read my post, you know that picture there, tells you how :nuts:

 

ahh nice lil link you gracelessly provided....

[HOrnbrod]

I think I'm going to join the club once I diagnose it for sure...mine died while backing it up yesterday and wouldn't restart. Also noticed it running worse and power was down when I moved it the day before. Sounds like it wants to catch every once and a while, but no joy. I can't find any evidence of the CPS ptach harness either, does anyone have the part number for that package, I can't seem to find it anywhere? :nuts:

 

The Mopar/AMC p/n is 83100066. 'Bout $85 from an OEM parts house.

[fiatslug87]

It says "200±75 ohms (hot engine)", if it won't start engine can't be hot is the reading different when cold as in the MAT or Coolant sensors?

[MiNi Beast]

Crankshaft Position Sensor

The Hall Effect type crankshaft position sensor is mounted on

transaxle bellhousing. The sensor reads slots (4 per cylinder) on

flywheel/flex plate. The signal generated provides engine speed and

crankshaft position information to PCM. The PCM uses this information

to determine proper fuel injection and ignition timing.

When a flywheel/flex plate slot passes the crankshaft

position sensor magnet, output voltage of the Hall Effect sensor goes

high (5 volts). When the metal between the slots is aligned with

sensor, output voltage goes low (.3 volts).

This high/low voltage signal is sent to PCM each time one of

the slots passes the crankshaft position sensor. The PCM uses this

information to determine when to energize the injectors for fuel

delivery to the proper cylinders.

 

Manifold Absolute Pressure (MAP) Sensor

The MAP sensor is mounted on engine compartment firewall. The

MAP sensor is used by PCM to calibrate amount of air/fuel mixture

supplied to the engine. This sensor measures manifold absolute

pressure. Ambient barometric pressure is also measured when ignition

switch is first turned on, during engine cranking, and at wide open

throttle.

The MAP sensor transmits a low voltage signal (1.5-2.1 volts)

at idle when manifold vacuum is high, and a higher voltage signal (3.

9-4.8 volts) during open throttle when manifold vacuum is low.

Input voltage (from the PCM) to MAP sensor ranges from 4.8-5.

1 volts. Adjustments made as a result of this input will usually

affect injector pulse width, ignition timing, idle speed and upshift

indicator light.

Manifold Air Temperature (MAT) Sensor

The MAT sensor is located on intake manifold, with sensor

element extending into the air stream. The sensor measures the

temperature of air entering the intake manifold. This sensor provides

an analog voltage signal to PCM. This signal is used to compensate for

changes in air density due to temperature.

The MAT sensor is a Negative Temperature Coefficient (NTC)

thermistor-type sensor. Its internal resistance varies opposite with

temperature. At cold temperatures, the resistance is high. As

temperature increases, its resistance decreases.

[jwilson25]

I think I'm going to join the club once I diagnose it for sure...mine died while backing it up yesterday and wouldn't restart. Also noticed it running worse and power was down when I moved it the day before. Sounds like it wants to catch every once and a while, but no joy. I can't find any evidence of the CPS ptach harness either, does anyone have the part number for that package, I can't seem to find it anywhere? :nuts:

 

The Mopar/AMC p/n is 83100066. 'Bout $85 from an OEM parts house.

 

Quick question...I checked mine tonight and found it had the new patch harness installed. Does this mean I can use the part number for just the CPS then and save a few bucks? Looks like the CPS is about $38, where as the package is $85. I unplugged it and replugged and viola, it started right up, so I think I know the problem now.