Ford Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter #1
My 97 TBird LX 4.6 has been running like crap lately, at speed she cuts out for a second or two, the tach drops to zero then she picks up again. This time she threw the following code.

P0320 Ignition/Distributor Engine Speed Input Circuit Malfunction

Sometime she'll stall when I'm idling and won't start, just cranks, after a few minutes of sitting starts right up. I had a similar problem two years ago where she'd die out completely. I replaced the crank sensor and that solved it. Maybe the same again? Maybe a cam sensor? Any thoughts.

Thanks.
 

·
Registered User
Joined
·
1,836 Posts
webzz said:
My 97 TBird LX 4.6 has been running like crap lately, at speed she cuts out for a second or two, the tach drops to zero then she picks up again. This time she threw the following code.

P0320 Ignition/Distributor Engine Speed Input Circuit Malfunction

Sometime she'll stall when I'm idling and won't start, just cranks, after a few minutes of sitting starts right up. I had a similar problem two years ago where she'd die out completely. I replaced the crank sensor and that solved it. Maybe the same again? Maybe a cam sensor? Any thoughts.

Thanks.
Here's a more current definition of P0320- No crank reference signal at PCM.
This is Chrysler's failure condition, your's is similar.
Set Condition: No signal from the crankshaft position sensor is present during engine cranking, and at least 3 camshaft position sensor signals have occurred. More than likely it's a CKP sensor but... in rare cases a bad CMP sensor can cause the 5V or 8V supply to colapse, causing this condition.
 

·
Registered
Joined
·
1 Posts
Hello,
I own a 1995 and a 1997 T-Bird, both 4.6 liter, automatics. The 1995 is not roadworthy because of getting hit in the driver's door by a person running a stop sign. :(

The 1997 is great. I also wrench on other vehicles as needed, and I am working through a P0320 code and similar issues on another 1997 T-Bird, 4.6 liter.

Did you ever find your problem, and if so, what was the ultimate solution?

I test drove the problematic car today to where I work, and back at the end of the day. One way mileage is about 12 miles. No issues on the way to work, but on the way back when I slowed down from freeway speeds of 70 MPH to city driving of 25 to 30 MPH, I could feel a stumble at certain part throttle conditions. It seemed to stumble and miss more than I would expect or have seen with my 1997 when I parked it and put it in neutral (no load on the engine). I shut it off, and checked it for set codes. There were none. The MIL was not lit. Now to go back a couple of days ago...

This car stumbled and quit a few days ago in a parking lot, but restarted immediately. It then acted like the key had been shut off for a split second, (tachometer rapid drop to 1000 RPM) while at 65 or so MPH. Then acted "normal" until getting into town. It then stumbled again. It was driven down city side streets where it up and quit like you turned the key off, and lit the MIL. There were two P0320 codes set. It sat about 15 minutes or less, until I could get to it after getting a panic phone call that it had quit. I cleared the codes, and it started right up like nothing happened. It was driven to my house, where it sat for a couple of days. There were no issues getting it to my place. No codes, no MIL, no stumble or stalling.

A bit of history...

This car was purchased by my GF about 6 to 7 years ago with over 100,000 miles on it. It has received a lot of preventative and restorative maintenance to this day. Regular oil changes, transmission fluid changes, differential oil change, suspension rebuild, belt, hoses, radiator, alternator, water pump, you get the idea. It suffered from a PCM issue where the PCM did not "boot" for several seconds on "key on" condition. Replaced the PCM with a NAPA rebuild. It lasted about 18 months or so, and then it would not start. No codes, but the MIL would not extinguish on crank, starting for a few seconds, getting progressively longer as time went by. Per the Ford OBDII documentation, the MIL will not extinguish on cranking if it fails to see signal from the crankshaft position sensor (and yes, you can't have any codes set either). Taking the low cost routes, the crankshaft position sensor was replaced - did not fix the issue. Had some moisture on the connector to the sensor, so the connector was replaced with an new one - did not fix the issue. Inspected the large body harness connector on the passenger side of the vehicle, inside the engine compartment - NO issues, it was as clean and tidy as the day it was built. The crank position sensor signal is generated by a reluctor type sensor which uses two wires. It is not the hall effect type sensor that uses three wires. The signal generated by the sensor goes through the connectors I mention, straight to the PCM and nothing else. Pretty simple and straightforward.

The ultimate solution was to replace the PCM AGAIN with one from a different vendor. The problem went away, and this was 15,000 miles and about 4 years ago.

Reading up on this code it again appears to be RELATED to stable and consistent crank position sensor signal. Some mention the camshaft position sensor as well, but from what I can read from the Ford OBDII manual (a 4 inch thick authentic Ford manual covering the 1997 model year of assorted Ford products), they don't seem to mention that. They want the wiring checked, the crank position sensor checked, and then they go on to describe testing the ignition with their specialized equipment. And, finally they mention changing the PCM.

I am leaning towards the PCM for the simple fact the sensor should not have failed in 15,000 or so miles. I don't believe the wiring to be at fault. The plug wires are lifetime mag suppression wires from NAPA, and I don't suspect they are failing. The plugs are Autolite Iridium XP104, with about 40,000 miles on them. There was some mention in the Ford documentation regarding arcing from the wires, bad plugs, and the like contributing to a P0320 code.

Thoughts on this issue? Has the problem that started this post been fixed? Anyone else with this issue, and a solution?

Thank you very much.

Brian
 

·
Super Moderator
Joined
·
20,344 Posts
You have tagged on to a 12 yr old post . The posters are no longer on this forum and will therefore not reply . You are better to start a new post .
 
1 - 4 of 4 Posts
Top