[RollTide]

Best start with some background. My 01 PT, non-turbo, 5spd is won't start. I started having issues about a month ago, when it left me stranded about 15 miles from home. Trailered it home, replaced the camshaft position sensor and the crankshaft position sensor, and fixed the frayed wire to the Crank sensor. All was good for a week or two, until I headed to Kansas City (about a 5 hour trip). It started acting sluggish, no power up hills, and got worse as I went along. Finally got to where I couldn't do more than 45 up a hill. Trailered it home again. Found the EGR actuator to be causing a vacuum leak, so I took the actuator out and blocked off the egr pipe with a piece of soda can, (disabled the egr) just to see if that would help before I spent the money on a new actuator. Car started fine, backed onto the road, and died, and hasn't started since. It cranks strong, timing belt is good (the camshaft turns, anyway), but I have no spark. Not even a little. The only codes in the computer are abs codes.
Anyone know what I should look for as far as the no-start issue goes? I guess I'll have to address the original problem eventually as well, but you know, one thing at a time!
It's got me baffled, because it was running fine when I backed it out, and it just quit. No coughing, no chugging, just shut off.
Any insight would be greatly appreciated.

 

[Bob Lincoln]

Check fuel pressure to see if the pump is working and if there is a clog.
When you turn the key to ON, do you hear the pump run for a second or two, then shut down?

 

[RollTide]

Thanks for the quick response! Yes, I hear the fuel pump cycle, then shut off.

 

[Bob Lincoln]

I've never replaced a crank or cam sensor, but many people here have mentioned that it's vital to get OEM brand, and also that the gap is critical. Given that you don't get spark, something is preventing it from firing. If the fuel pump cycles, the ASD relay must initially be closing as it should, then opening. That could be due to a missing crank or cam sensor input.

 

[AllanC]

. . . If the fuel pump cycles, the ASD relay must initially be closing as it should, then opening. That could be due to a missing crank or cam sensor input. . . .

As Bob L mentions you know that the power circuit to the electrical fuel pump is good and the PCM is able to control its operation.

Try this test. Turn off all devices / radio that make noise. Fasten seat belt to silence warning buzzer. Engage starter for 5 seconds. Release key switch to RUN position. You should hear the electric fuel pump continue to RUN for 1 - 2 seconds and then stop. If you hear it run for a few extra seconds then you know that the PCM is receiving a proper signal from the crankshaft position sensor to engage the fuel pump.

If NO continual running for 1 - 2 seconds then there is a problem with the crankshaft position sensor or the wiring from the sensor to the PCM.

If you are getting no spark check the primary side ignition wiring to the coil pack. There is an electrical noise suppressor (capacitor) wired into the system. Make sure it has not failed and is shorted to ground.

 

[ImperialCrown]

Welcome to Allpar. A PCM would not store ABS codes. What are these codes and how are you reading them?
Perform the 'Engine cranks but does not start' test on p. 222 here:
http://oskin.ru/pub/chrysler-dodge/manuals/Service Manuals/2001_PT_PTCruiser/01PTEP.PDF
Was the CKP sensor wiring frayed by chewing? Is it possible that varmints have chewed other wiring?
You have power at the positive side of the coil while cranking? The negative side is 'switching' while cranking?
A good OBDII scan tool should see the cam and crank sensor signal being 'present' or 'lost'.

 

[chuzz]

Pull your air box and check the ground connections inside the driver side fender. Don't just look and see if they're attached, make sure you grab the wires and they are not corroded and broken. The gas that leaks out of the battery will attack these ground points and cause problems after years of neglect. All it takes is about 10 minutes of your time.

 

[RollTide]

Thanks to all for your input. Been working on the car as I have the time, and now I have a new set of questions. I've verified that the asd relay is good (it clicks on for a second when the key is turned on, comes on while cranking. Also swapped it for the horn relay, which works). I also checked for voltage at the green/orange wire at the coil plug, and I have voltage while cranking. However, while the key is off (and the pcm unplugged, incidentally), my meter shows a ground on that wire. Doesn't register continuity to ground, but shows 12v if I meter it between that and battery positive. This is the wire that goes from the asd output to the coil and the injectors. Maybe I'm wrong, but I don't think there should be a ground there. Anyone?

 

[RollTide]

Welcome to Allpar. A PCM would not store ABS codes. What are these codes and how are you reading them?
Perform the 'Engine cranks but does not start' test on p. 222 here:
http://oskin.ru/pub/chrysler-dodge/manuals/Service Manuals/2001_PT_PTCruiser/01PTEP.PDF
Was the CKP sensor wiring frayed by chewing? Is it possible that varmints have chewed other wiring?
You have power at the positive side of the coil while cranking? The negative side is 'switching' while cranking?
A good OBDII scan tool should see the cam and crank sensor signal being 'present' or 'lost'.

Yes, power at coil while cranking. No switching negative on the other two wires. I guess this means the computer isn't signaling the coil? Could it be a short somewhere?

 

[AllanC]

Yes, power at coil while cranking. No switching negative on the other two wires. I guess this means the computer isn't signaling the coil? Could it be a short somewhere?

In post #5 dated Aug 15 did you perform the test outlined to engage starter for 5 seconds and then listen for fuel pump running? Did you check the electrical noise suppressor / capacitor for short to ground?

 

[RollTide]

As Bob L mentions you know that the power circuit to the electrical fuel pump is good and the PCM is able to control its operation.

Try this test. Turn off all devices / radio that make noise. Fasten seat belt to silence warning buzzer. Engage starter for 5 seconds. Release key switch to RUN position. You should hear the electric fuel pump continue to RUN for 1 - 2 seconds and then stop. If you hear it run for a few extra seconds then you know that the PCM is receiving a proper signal from the crankshaft position sensor to engage the fuel pump.

If NO continual running for 1 - 2 seconds then there is a problem with the crankshaft position sensor or the wiring from the sensor to the PCM.

If you are getting no spark check the primary side ignition wiring to the coil pack. There is an electrical noise suppressor (capacitor) wired into the system. Make sure it has not failed and is shorted to ground.

View attachment 19613

How would I go about testing the capacitor? Where is it?

 

[AllanC]

How would I go about testing the capacitor? Where is it?

Look at attached image. Follow the wire DG / OR from the coil to splice 103 and then onto the capacitor.



Follow this link to instructions for testing capacitor. Use method #3.

How to Test a Capacitor? 6 Ways to Check a Capacitor. - Electrical Technology (at https://www.electricaltechnology.org/2013/06/how-to-check-capacitor-with-digital.html )

 

[RollTide]

Look at attached image. Follow the wire DG / OR from the coil to splice 103 and then onto the capacitor.

View attachment 20071

Follow this link to instructions for testing capacitor. Use method #3.

How to Test a Capacitor? 6 Ways to Check a Capacitor. - Electrical Technology (at https://www.electricaltechnology.org/2013/06/how-to-check-capacitor-with-digital.html )

Ok, so I tested the resistance on the capacitor (positive lead on the spade connector, negative where it bolts to the head, meter set on 2000 ohms) and I get no reading at all. Does that mean the capacitor is bad? Also, even with the wire going to the capacitor disconnected, I still show a ground on the green/orange wire. Not continuity to ground, but 12v if I check between that and battery positive. Is it normal to have ground on that wire? Seems like it wouldn't, since it's the 12v supply for the coil.

 

[ImperialCrown]

A good cap will test open with an ohmmeter. It sounds like there is a short to ground somewhere along that DG/Or wire. Disconnect and isolate components on that circuit until the short to ground goes away. The short to ground could be the wire itself if it is cut, pinched or rubbed-through somewhere along its length.

 

[AllanC]

. . . A good cap will test open with an ohmmeter. . . .

I agree that in testing a capacitor it may show a reading momentarily (if charge still present) and then show an open circuit (no reading). As I C suggested disconnect devices powered by the ASD relay output and check for ground until it disappears.

It appears from the wiring diagram that all feeds from the ASD relay output to devices are ground side switched or sensed by the PCM. I would first disconnect C1 connector and determine if the ground on wire DG / OR disappears. If still present then disconnect C3 connector at PCM and determine if the ground on wire DG / OR is still present.

If the ignition switch is in the OFF position are all of the ground side switched solid state circuits within the PCM immediately transitioned to an OPEN status? I would think it possible that some solid state circuits have continuity to ground when NOT powered up?

 

[AllanC]

. . . Ok, so I tested the resistance on the capacitor (positive lead on the spade connector, negative where it bolts to the head, meter set on 2000 ohms) and I get no reading at all. . . . .

You tested the capacitor and found it is not shorted to ground. Did you run the test to engage the starter for 5 seconds and then return key switch to RUN position and listen for sound of electric fuel pump running?

 

[RollTide]

A good cap will test open with an ohmmeter. It sounds like there is a short to ground somewhere along that DG/Or wire. Disconnect and isolate components on that circuit until the short to ground goes away. The short to ground could be the wire itself if it is cut, pinched or rubbed-through somewhere along its length.

Ok, so I started pulling connectors. Nothing changed until at the very last I unplugged the pcm, and then the ground went away. Maybe that's normal? Computers. Ugh.

 

[AllanC]

. . . so I started pulling connectors. Nothing changed until at the very last I unplugged the pcm, and then the ground went away. Maybe that's normal? . . . .

You found a situation where certain circuits that are ground side switched by the PCM have continuity to ground when the PCM is NOT powered up. So that would be normal. You proved that the wire DG / OR is not shorted to ground.

Did you run the test to engage the starter for 5 seconds and then return key switch to RUN position and listen for sound of the electric fuel pump running?

 

[RollTide]

You found a situation where certain circuits that are ground side switched by the PCM have continuity to ground when the PCM is NOT powered up. So that would be normal. You proved that the wire DG / OR is not shorted to ground.

Did you run the test to engage the starter for 5 seconds and then return key switch to RUN position and listen for sound of the electric fuel pump running?

Yes, I checked that. Fuel pump seems to be running.