Question about fuel injectors

[roadbratt]

Hello, I have a bad misfire problem going on, and we know it might be electrical, but we arent sure until a specialist looks at it, and keeps the car for a week. But in the meantime, we want to try to find out the problem ourself. The misfire isnt constant, and it comes and goes.. it seems that the air temperature has something to do with it. We think that the fuel injectors might have somethign to do with it, because we replaced the ignition coil and the plugs, and it's still misfiring.. and the computer isnt telling us anything related to the area. Would fuel injectors contribute to a misfire?

Also, the tach jumps around a lot right before it starts to misfire while driving, or right before it corrects itself(stops misfiring). I think the tach might be connected to somethign that is bad too. Any ideas or questions about the misfire that has been going on for about 5 months, let me know. Thanks

-Andrew

<small>[ May 26, 2003, 12:20 AM: Message edited by: roadbratt ]</small>

 

[NotSoSlowSHO]

You mentioned you changed the plugs... but what about the wires?

Bouncy tach? How about a bad CPS?

<small>[ May 26, 2003, 12:01 AM: Message edited by: NotSoSlowSHO ]</small>

 

[roadbratt]

No, we havent changed the wires, but i might go out and buy a set if the price is right. Also, whats a CPS? (i'm a newbie).

 

[LaTechSHO]

I'd be thinking more in the realm of the CID... Camshaft Identification Sensor .... FYI the CPS is the Crankshaft Position Sensor. It is my understanding that either of those sensors should throw a code, but sometimes things do not act as they should. I'm sure someone will chime in with the perfect diagnostic procedure, but the CID is my guess.


Louis

 

[rangerj]

Roadbratt,

CPS is the Crankshaft Position Sensor. In the last week there was a post by me explaining the tests for the distributorless ignition system (DIS) that includes tests for the CPS, the CID (Cylinder Identification Sensor or camshaft position sensor), the DIS module, the coil, and the IDM (Ignition Diagnostic Module). Do a search for the post. I think it is in the last five days.

You can do a simple test to determine if the fuel injectors are working. Put a mechanics stethescope on the injector and listen to it "click". This will tell you that it is working mechanically and electrically.

It will not tell you if it is clean. You can do the same thing with a screwdriver, Put the tip on the injectors and the handle to your ear and listen to it "click".

The TPS has a direct relationship to the tach!
rangerj