ECONOMECHANIX
4404 NW 13th Street #25, Gainesville, Florida 32609
(352) 376-5624 / Fax (352) 376-5624

Here's some questions I've answered about vehicle cold start/run problems. Maybe they can help you sort out your problem! If not, feel free to contact me!.

George

THANKS FOR YOUR HOME PAGE I JUST GOT MY FIRST COMPUTOR AND MY TRUCK JUST WENT DOWN SO I DECIDED TO LOOK ON THE WEB TO SEE IF I COULD FIND ANY INFO ON THE PROBLEM

First I should ask if you give free technical information? If so, could you answer the following question?
I have a 1993 S10 Blazer that does not high idle in colder temperatures. It has a fuel injected 4.3 liter V6 in it with a manual transmission. Would this lack of cold starting aid come from a bad temperature sensor? If so, where is it located and is it costly to repair?

Could be that, could be the idle speed control stepper motor. It bypasses air at idle around the throttle plate to control the idle. The temp sensor is by the thermostat housing: the 2 wire connector. they have devices to extract the computer trouble codes at many parts stores: that and a good book is what you need.

George

Is there a problem with warming up a car in the morning? is there a time limit? it is a newer car 1998. i was told it is not good to let them run in the mornings - is this true? M

thanks

The idea behind "warming up" a car in the mornings used to be because driveability was so bad that if it didn't run for awhile it would stall out. The idea of NOT warming up a car in the morning is that a cold engine has loose tolerances. (metal parts expand: the're too small when cold.) Also, the cold, thick oil takes a while to reach the far reaches of the oil passages. Cars have a "fast idle" mechanism: this idles the engine faster when cold. A carburated car has a fast idle cam with several steps. If started and left to idle, it will stay on the fastest step of the fast idle cam even after it starts to warm up. You have to tap the gas pedal and "kick the idle down". This fast idling of a semi warm engine is not good for it.

Your car, however, is computer controlled and fuel injected: the computer adjusts the idle speed down as the engine warms up whether you touch the gas pedal or not. Thus the REALLY BAD scenario of over-revving a cold motor on the top fast idle cam cannot happen.

The preferred engine warmup routine today is this:

1) Start the car. Wait for the oil light to go out or the oil gage go up.

2) Any time after you have oil pressure, you can drive away. Take it easy and under 45-50 MPH (the slower the better) until the engine warms up (about 3-5 miles or 5-10 minutes)

If your heater is warm, so is your motor. Drive as normal.

The reason for "warming up under load" is that going down the road slowly the engine is often at a lower RPM (esp. automatic tranny models) than warmup at idle; DEFINATELY better than revving the engine in the driveway!!

Of course sometimes it's nice to run from a warm house to an already warm car. With yours, any warmup method would do, except for the revving in the driveway style! However, letting it warm up for few seconds before gently driving away is all you need to do. A longer warmup won't hurt the car, but neither will it help.

George



DON'T BE STRANDED!
AT ECONOMECHANIX WE CAN MAKE YOUR CAR RUN RIGHT IN ALL KINDS OF WEATHER! GIVE US A CALL AT 352-376-5624.

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Gainesville has been my home since 1974, and I've loved Gvl and the Gators since I came to Gainesville in the fall of 1974 to attend the University of Florida. I loved it so much I stayed and opened my car repair business. Originally it was out of the back of a 1963 Chevrolet wagon, but in 1977 a fellow mechanic and I opened an auto repair shop with actual walls, etc. Fixing cars for over 20 years now from the same address (just more auto repair bays now than then) , we'd love to be your mechanic shop! George G. Scott, Jr.