I have a really weird issue when I do a cold start and it’s under 40 degrees outside, it will crank and run for about 5 minutes and then cut off with dashes at the odometer. I can turn it on and off and I can hear a bunch of relays clicking as the ecu is resetting. This can take a couple tries to keep it running and not stalling out. It gets worse the colder it is which is a pain with getting to work in the morning. If it’s not cold there are no issues whatsoever. Been this way for over a year with no signs of getting worse. I checked grounds and they were good. Can ccrm cause this? Or maybe ecu but it has no other issues. It is a 2000 gt 5 speed for reference but it has the 03-04 drivetrain. Any ideas of what the issue is or other things to check would be very helpful. Thanks!

 

Welcome,

Using a Heat Gun or Hair Dryer Warm The Suspected Part Before The First Start of The Day and if it The Problem Goes Away You Found The Affected Part. Start With Pcm. Not TOO Hot Now!

Also Have You Tried Pulling any Diag Codes?

https://themustangsource.com/forums/...ncerns-550469/

KC

 

Ok I’ll give that a shot. Yeah I’ve pulled codes and only have a p0420 code. But my cats are not clogged because I tested back pressure and they were good.

 

The P0420 Could Also Indicate a Bad Ect Sensor as Per Ford Chart. Worth a Thought Although Likely Not To Cause A Severe Issue as You Have. Ford Sensors Have Been Known To Cause Weird Issues!

If You Choose To Pursue I Would advise a Motorcraft!

https://www.rockauto.com/en/catalog/...+/+sensor,4748

P0420 - Catalyst System Efficiency

DESCRIPTION

Below Threshold (Bank 1)
Indicates the bank 1 catalyst system
efficiency is below the acceptable
threshold.

CAUSES

Use of leaded fuel
Damaged HO2S

Malfunctioning engine coolant
temperature sensor.

High Fuel Pressure
Damaged exhaust manifold
Damaged catalytic converter
Oil contamination
Cylinder misfiring
Downstream HO2S wires
improperly connected
Damaged exhaust system
pipe
Damaged muffler/tailpipe
assembly
Retarded spark timing
Leaking fuel injector

 

Ok that’s good to know. I am suspect of leaking fuel injectors which I will be cleaning and rebuilding this weekend. And ect sensor has been replaced with a cheap one from po so I’ll probably change that or at least test it. Other than ccrm and ecu, is there anything else I should try heat gun on?

 

Perhaps Cluster But Be Careful Maybe Blow Under Dash!

30+ Years in Dealership Ford Parts and Sensors Were Many Times The Culprit When Cheapo's Used. Been Bit Myself With a Cheapo Crank Sensor on a Dodge! Ran Me in Circles and Replaced a Good and Very Rare PCM it Did Not Need! Lesson Learned! Oem Sensor Was The Fix.

KC

 

Idk bout cluster. Don’t see how a cluster that has no other problems would cause my issue. That’s funny cause I ran into same issue with crank sensor on a jeep. I also have a hard time seeing how heat gun would fix my issue on ecu and ccrm because neither of those would get warmed up as I get my motor warmed up enough for ecu to not lose signal. I’m gonna still try it though.

 

Ecm is in Rt Kick Panel By Heater?? All You Can Do is Try Sometimes The Odd Things That Pop into Your Head The First Thing are The Right Thing To Try Even Though as You Second Guess it It Seems Less Likely. Anyhoo This Old Man Has Seen Way Too Many Weird Things With Cars Not To Try & Think Outside The Box a Bit. Could Be SomeThing in Engine Compartment Where Heat Would Surely Affect Change Sooner. always a Process of Elimination. Cold Causes Contraction and Heat Expansion and Your Temperature Sensitive Issue Can Be The Difference of Just a Few Degrees. Remember The Newer The Car The More Like Driving a PC on We Wheels We are Dealing With! It's Getting Crazier Every Year!

I Had a No Start on My 02 Harley F-150 Super Charged Which Only Happened Most of The Time To My Wife Of Course. Turned Out Years Before When I Had The Cylinder Head Replaced and The Cab Was Lifted They Stretched The Wire To The PATS Transciever. When The Wife Would get Out of The Truck She Would Put The Steering Wheel Up and It Would Not Start! I Always Left Wheel Alone! So I Did Not Have Issue! Drove Me Crazy Finding That One.

KC

 

If Your Code Reader Only Does The P-Codes and Does Not Retrieve B Codes You Might Borrow One or visit a Local Parts House And See if Any Body Codes are Present Which May Shed Some Light on Issue! Just a Thought!

KC

 

Well I don’t run heat as I’m trying to get it able to stay running because it seems to do better with heat off. But yeah definitely worth a shot. And I might be able to use this issue to get the wife’s ok to get a better scan tool hahaha. I’ll look into body codes and see if I can track this issue down.

 

You Had Mentioned a Powertrain Swap. I Wonder if You Have a Good Engine To Body Ground Strap. That gets Overlooked Sometimes. Not Sure On Your Model But a Lot Of Cars Would Have a Brush Strap Connection From Block To Body Usually Behind Intake To Firewall Generally Anyhoo! Can Cause A Host of Odd Issues if Lacking and Would Not Hurt To Just Add One For Grins!

Kc

 

Yeah it actually was missing and I put one on with no change in the issue. I went through and voltage drop tested every ground point on the car.

 

It's Gonna Be Something Goofy! I Feel it in My Bones!

KC

 

I’m sure of it. I never get the common fixes. Always something very unusual that takes deep digging.

 

This car is now 25 years old, we have to remember that capacitors in the ECM have a shelf life and you are at the point that this could be the issue. Dashes in the odometer suggest electrical gremlins to be the cause. The ccrm has nothing to do with the dashes in the dash, the ECM does though.

Leaking fuel injectors will not cause the dash problem you are experiencing. It's a good idea to rebuild the injectors(I do this in my shop) and it will make an improvement but I don't believe it's going to fix your problem.

So...Temperatures have a huge impact on things sometimes. I had a 2008 GT500 come in with an overheating issue. You could start the car cold and it would overheat, fan would not come on and it would overheat, could not figure out what was going on. Left to go to lunch and came back to get back on the car. Fire it up and everything worked, fan came on and the car would not overheat. Puzzling right? Well these cars are known for burning up the connector at the fan, this one had not done that...but trace back in the harness under the fuse box and it had melted the high and low speed connectors at the junction. What happened was when I let it sit, it heat soaked and things expanded JUST enough to make contact on the low speed fan connector so it would work.
Now on the ECM/ECU...heat can cause issues there too. But diagnosing from a distance like this is nearly impossible and I am one who hates to throw parts at a problem but if you are left puzzled then given that it's 25 years old I would suggest sending your ECM out to a place like ECU Exchange and have them go through it and replace the capacitors, voltage regulator and test it on their end. Due to the age it doesn't hurt as a form of preventive maintenance. I have a stack of 17 ECU's in my office that all need repair like this due to age. A Crank position sensor couldn't hurt to try either but that also would not cause the dashes in your odometer.