Car lacks power in cold temps before engine warms

[Sedin26]

I've got a 1993 Tercel. It starts and idles well in all weather and circumstances.

Last winter, I noticed that in the morning, before the motor warmed up, the throttle wouldn't respond promptly. The car would either slowly start moving or wouldn't respond for a few seconds and would then go.

The problem mostly went away over the summer but now that it's starting to be a bit colder in the mornings again, the issue has returned.

It does go away once the engine has had a chance to warm up for 4 or 5 minutes and get up to operating temperature.

 

[Quest]

Is it carb'ed or electronic fuel injection?

If it's carb'ed then most probably your choke or cold idle is too lean/too rich. If it's EFI then it would be another story.

Q.

 

[jorton]

I think the parking brake is sticking for some reason, unless(that is) you aren't using it.

 

[chad8]

efi on older toyotas has a cold start valve. Also called an idle enrichment. Used to be called a choke before electronics. It basically pumps more gas in when cold. Yours is going or gone. plenty of them at junkyards.

 

[chad8]

the 93 has a temp sensor instead of a cold start valve. You need to get a obd 1 reader and see if the ecu has set a code. Here is a list of the codes. Probably will be a code 8 or 23.
$30 part.

Trouble Codes

OBD1 Codes
1 Normal Condition.
2 Air Flow Meter signal.
3 Ignition signal.
4 Engine Coolant Temperature Sensor signal.
5 Oxygen Sensor.
6 RPM signal (Crank Angle Pulse).
7 Throttle Position Sensor signal.
8 Intake Air Temperature Sensor signal.
9 Vehicle Speed Sensor signal.
10 Starter signal.
11 Switch signal.
11 ECU/ECM.
12 Knock Control Sensor signal.
12 RPM signal.
13 Knock Control CPU (ECM).
13 RPM signal.
14 Turbocharger Pressure.
14 Ignition signal.
21 Oxygen Sensor.
22 Engine Coolant Temperature Sensor signal.
23 Intake Air Temperature Sensor signal.
24 Intake Air Temperature Sensor signal.
25 Air-Fuel Ratio Lean.
26 Air-Fuel Ratio Rich.
27 Sub Oxygen Sensor signal.
28 No. 2 Oxygen Sensor signal.
31 Air Flow Meter signal (Vacuum Sensor signal).
32 Air Flow Meter signal.
34 Turbocharger Pressure signal.
35 Turbocharger Pressure Sensor signal.
35 HAC Sensor signal.
41 Throttle Position Sensor signal.
42 Vehicle Speed Sensor signal.
43 Starter signal.
51 Switch signal.
52 Knock Sensor signal.
53 Knock Sensor signal.
54 Inter-cooler ECM signal.
71 EGR System.
72 Fuel Cut Solenoid signal.
78 Fuel Pump Control signal.
81 TCM Communication.
83
TCM Communication.
84 TCM Communication.
85 TCM Communication.
from
http://www.troublecodes.net/Toyota/

 

[mechtech2]

If you have a coolant sensor, check that first.

 

[chad8]

you might be right...

 

[Sedin26]

It is EFI. Definitely not a parking brake issue.

Thanks for the suggestions - I'll do some checking and see what I come up with.