Redcivic

What's up fellas!? Well, I have this little problem with my GXE where my car kind of lurchs/bucks when the car is at a stop,in drive,foot on the brake,with the A/C on. When I turn the A/C off it stops. Well, I figured out what it is. It is the Fast Idle Cam. It was out of adjustment by a lot. So, I adjusted it to the proper settings (as per the Haynes) and it worked like a charm. For a week anyway. Now it is out of adjustment again and I fear that it is screwed. So, can anyone help me check for sure. The Haynes talks about checking the resistance of the coolant temerature sensor. I have tried that but I think I am doing something wrong(I know very little when it comes to Ohms law and crap like that). Anyway, I need to know for sure if it's bad, and if it is, is there anyway to fix it? It looks like I would have to replace the whole throttle body. How much would that run?

Daniel B. Martin

This is unfortunate. All modern cars have one or more computers and rely heavily on electronics. If you are serious about fixing cars you will have to learn a lot about "Ohms law and crap like that." If you can't learn, or don't want to, that is okay. Find a local mechanic who is competent and trustworthy. You will get to know him well.

Eric L.

There's really not much to Ohm's Law. V=IR. There. That's all you need to know. V=voltage, I=current (in Amperes), R=resistance (in Ohms). The rest is math.

Electrical problems are difficult to diagnose. They are best handled by a reputable shop if you can't figure things out with a multimeter.

Redcivic

Oh, but I do want to learn. I managed to swap the motor out of my civic with some ease but the problems I did have were with the knock sensor wiring etc. How do you suggest I learn without using my car as a pratice dummy? Are there any books you can recommend? All feedback is greatly appreciated. What do you think about the fast idle cam?

Daniel B. Martin

1) The Chilton repair manual has some good material in pages 6-2 through 6-7.

2) The Haynes repair manual has some good material in pages 12-1 through 12-5.

3) There's a lot of good basic instructional material to be found on the Web. For example, go to http://autorepair.about.com/cs/electrical/index.htm and click on any of the links found there. Two of them look especially good for your purposes: Basic Automotive Electricity and Basic Wiring.

4) There is no need to use your car as a guinea pig. Visit any auto repair shop or dealership and ask for dead bulbs, switches, relays, solenoids, door lock actuators, etc. Learn to use an ohmmeter to figure out which bulb filament is bad. Carefully cut open the plastic housing on a relay so you can see the insides. Experiment with your ohmmeter to learn what part is good and what is bad. Maybe you will find a switch or a relay with burned contacts. Use a fine abrasive to polish the damage away and then measure the resistance again. You can teach yourself how to repair parts as an alternative to replacing them. Make up a pair of fused test leads with alligator clips at each end. These will be useful with your meter. You can do all these things "on the bench" with junk parts and without the risk of "frying" delicate electronics in your car.

Just two days ago I had a "dead" Honda door lock actuator in my hands. It had only two wires, so it couldn't be too complicated. The ohmmeter indicated a good circuit inside but applying 12 volts didn't produce any motion. I opened it (five screws) and discovered a tiny electric motor in perfect condition, but the grease around the plastic worm gear attached to the armature had turned into waxy garbage. Added some grease... good as new! Love those zero-dollar repairs!

5) As your skill and confidence level improves begin to measure the non-sensitive parts of your car. Measure the voltage across the battery terminals before cranking, while cranking, and after cranking. In general, the readings will be around 12 volts before cranking, somewhat lower while cranking, and somewhat higher after cranking. You will learn what "normal" is for your car. A cranking volatage below 10 volts indicates a battery problem. A charging voltage above 15 volts indicates a voltage regulator problem.

After a while these terms and concepts will be less mysterious. You don't have to become an engineer to acquire useful diagnostic skills with a multimeter.

Daniel B. Martin

AFAIK the fast idle cam is operated by a Thermo-element which is not electric. It is operated by the heat from the engine coolant which circulates through the Throttle Body. If you did the Throttle Body Coolant Bypass mod, that would cripple the fast idle mechanism. These thermo-elements rarely fail. I don't know if it can be replaced as a seperate part. That question should be directed to the parts man at your local friendly Nissan dealer.

Redcivic

I appreciate the feedback! Very Good. I will measure the resistance of the coolant temperature sensor and let you know how it goes. Excellent fellas, Excellent!

sp6040

I appreciate the feedback! Very Good. I will measure the resistance of the coolant temperature sensor and let you know how it goes. Excellent fellas, Excellent!


there has to be a certain amount of resistance this sensor registers on your meter.there is usally an allowable resistance range on all sensors which will determine if the sensor is good or bad.i dont know what this range is im just trying to help.find out what this range is then you'll have your answer to whether its good or bad.

Daniel B. Martin

Make a careful visual examination of the harness and connector which attaches to the Engine Coolant Temperature Sensor. Try wiggling those wires with the engine idling to see if you can trigger the lurch/buck symptom.