1993 Subaru Cold Start Problem

[93WinterWonder]

My 1993 Legacy has had problems starting in the last month, January 2025. The weather is in the low 20s to 0 degrees. The battery is fully charged, and the starter motor works perfectly. The motor usually starts with a few rotations and the RPM bounces up to 2500 and then slowly adjust down to 500-800 range. Today it turned over for two minutes before starting and acted as if it was not getting fuel and then slowing adjusted to normal with the Engine Light On. Then when I drive the engine light goes out and everything is normal, though once the motor cools down it will again be difficult to start. The exhaust system and O2 sensor are new.

I have had this car for about eight years. It has been in the family for over 20 and has always been very dependable. Is there anyone who knows about this issue, with difficulty starting? Would it be vacuum or electrical problem? The 60 thousand was done and the motor is clean, and the car would not of had any major past mechanical issues, so it's got to be just one thing. What could it be?

93WinterWonder

 

[bmart]

Define full charged. Has it been load tested? Right battery for the car? What are the battery build date and install date?

 

[Raymond3006]

Define full charged. Has it been load tested? Right battery for the car? What are the battery build date and install date?

Check your Ignition Wires & Spark Plugs ....

 

[93WinterWonder]

Define full charged. Has it been load tested? Right battery for the car? What are the battery build date and install date?

It has not been load tested. I am not sure if it's the right battery. Without looking I am not sure of the build date and install date. By full charged I mean I could turn the ignition key and the motor would turn until I have concern for the starter motor, a few minutes and it does not seem to lose power. I don't feel its the battery though maybe I should have it tested. I hadn't thought of that. Thank You.

 

[93WinterWonder]

Check your Ignition Wires & Spark Plugs ....

I have looked at the park plugs an ignition wires. The spark plug seal gromets have been tightened and loosened a few times, so maybe they need replacement. As far as the plug carbon or oxidation I don't see anything they just look clean. This combustion cycle has good ignition though its just not getting fuel on startup for some reason. Once its started it runs normal, power on demand, smooth idling. The start however is as if the computer is not giving the conditions needed for starting and its starting at the conditions for once it's at normal temperature. This requires me to either pump the fuel peddle or hold it down looking for the correct ignition balance. Wires are new, or mostly new. They look new. Thank You.

 

[Raymond3006]

Wondering .... : since you have a really Great-Battery, look elsewhere ... Electronically : possible the Crank-Sensor, or the Cam Sensor(s) ; possibly one has been damaged by Oil-Intrusion and is putting out a weak-signal.

The one other (dismal ..... ?) possibility would be the ECM itself is slowly dying ..... : SORRY !!!!

 

[Raymond3006]

PS : forgot to add the Throttle-Sensor ...... to the Electronic Basket of possibles.
How long have you been starting vehicles using you foot on the Gas-Pedal ...????

 

[93WinterWonder]

February 13, 2025, Yesterday, was another difficult start and again after it was warmed up everything functions great. The difference between yesterday and the last two week I take Legacy on a long drive out of town and into the back country for some cross-country skiing. The under carriage got a little snow bottoming out as the clearance was shallow, and I can't advise driving in deep snow though I noticed this morning when I was going out for a second field trip the Subaru started right up without any issues. My conclusion is I was not complete warm-up in town and by driving a longer distance fixed the signalling issues, supposedly. Perhaps the thermostat was not completely opening. I don't think driving through the snow fixed anything however, that does not make sense. I did however after some reading order a new Subaru Legacy Coolant Temperature Sensor and I think if a person was going to replace an easy part this may be one for consideration. Thank You.

 

[Raymond3006]

Slow-Start : and Starting with foot on "Gas" ;
That starting technique went OUT with the last of the Carburetors !
It WAS used in Two-Situations : (1) To clear a Flooded Engine (which came from too much Pumping of the Accelerator Pump by The FootFeed !!) ; and (2) To reset the Fuel Level in a Carb caused by Vapor-Lock (when gasoline boils in the Bowl due to HIGH Ambient OR Intake-Manifold/Engine Temp. All of these things are never supposed to happen to any modern vehicle .....

For all ECM (aka, Brain-Box , ... or Computerized Cars, ... ) starting is done with the Foot On-The-Brake, AND NOT ON THE FOOT-FEED .... ! If your vehicle actually NEEDS to have the Throttle Sensor OFF OF ZERO POSITION for Starting, then it is either WAY OUT of Calibration, .... or is FUBAR .....(!) , and desperately needs to be replaced . (period)