how can i set my iac with out my tach working right?, oh and by the way how can i fix my tach lol

 

i mean the min idle speed

 

ok i have a new problem i was going to try to set the tps, and i am not getting any voltage to it i even put the leads into the tears to see if anything was going to it and i cannot get a reading , the tears are not big and i can not see any wires that are cut just in the plastic covering. help please

 

If your factory wiring harness has not been tampered with then you can assume that your tach is failing. However, the IAC can not be set as it is a motor used to fine tune the idle and is controlled by your computer. For your computer to control the IAC correctly you will need to know the RPM for the TPS adjustment. You will need to fix your tach or find and external tach as a temporary test device. The correct procedure is to disable the computer per the service manual, set the timing, then set the idle using the throttle body screw. Once this is done you will need to set the TPS output to the correct voltage as specified for your vehicle and engine type. When all of these conditions have been met, reconnect the link to re-enable your computer. The computer should now adjust the idle as needed and all should be well providing there is nothing defective with your IAC motor. Find a service manual and follow exactly for the vehicle you are servicing. I am not going to quote RPM's and TPS voltages here because they do differ. Good luck. RE in Macungie, PA..............

 

Hope you have a basic understanding of troubleshooting and electrical wiring in vehicles. Am looking for my service manuals.

 

OK, you posted a new symptom while I was typing my first reply. You should see 5V across two of the wires and the third wire should be the voltage signal to the computer that is adjusted using the procedure previously described. I don't have my manuals handy right at the moment or I could tell you which color wires should have 5V, but from memory it should be the two outside wires with the middle wire feeding to the computer. If you are missing this voltage you will need the wiring diagrams to determine where the failure is occurring. Good luck, RE.............

 

well i guess im sol because i just began the trek of tpi and i know very little about this kinda stuff. any help would be great.

 

ok here you go;

click -> clean your IAC

click -> adjusting minimum air (or idle speed)

click -> adjusting your throttle position sensor (TPS)

 

Depending on the year, the TPS is generally not adjustable. The IAC air must be cut off to set minimum air rate. Once the minimum air rate is adjusted, the TPS is set. The IAC takes it from there, commanded by the computer.

 

Or simply read the informative tech article here that includes pics as well.

later
Jeremy