R Holland Posted August 14, 2014 Author Report Share Posted August 14, 2014 The IAT measures the incoming air temp to the intake. As we know, air density changes with air temperature, meaning the amount of oxygen in say a cubic foot of air will be less when the air is 100 degrees verses 32 degrees. So basically the computer uses the air temp to help determine air density and adjusts fuel ratio accordingly by lengthening or shortening the amount of time the fuel injector stays open. Symtoms of a bad IAT sensor are rough idle and longer cranking times. Both of which I still had after repairing everthing else. My '84 Trans Am with OBD1, used a BARO sensor or barometric sensor to deteremine air density. From there the computer would signal the mixture control solenoid on the carburetor to adjust how much the primary metering rods would open. Quote Link to comment Share on other sites More sharing options...
ron350 Posted August 14, 2014 Report Share Posted August 14, 2014 Thanks I will have to pick up a couple of IAT sensors at the salvage yard. Quote Link to comment Share on other sites More sharing options...
mikecoachusa Posted August 25, 2014 Report Share Posted August 25, 2014 try replacing the fuel pressure regulator Quote Link to comment Share on other sites More sharing options...
R Holland Posted September 2, 2014 Author Report Share Posted September 2, 2014 Mike, I did that in the beginning, but it didn't fix the issue. Since replacing the IAT sensor, the engine runs fine. I've been daily driving this car to work for the last 3 weeks with no problems. This car had a slew of issues when I first started working on it though. The girl I bought it from did no maintenance other then oil changes. I've replaced the plenum, intake gaskets, full tune up, pretty much every sensor was replaced due to either engine code coming on or diagnostics showing that it was failing. Quote Link to comment Share on other sites More sharing options...
Twinpilot001 Posted September 9, 2014 Report Share Posted September 9, 2014 does car have an inline metal fuel filter in rear tank area?? if so change it .= cold starts are usually due to a bad temp sender (computer) and many times there are more than 1 on engine. iac =?= did you read on how tio reset it after a new install?? need to. from some experience with fuel pumps- dont use a non-name brand pump!! Gm or napa is best as ive learned!! I also would start by checking all sensors on engine for the 5v reference input! likely there is a temp sender bad or an emissions sender thats not within specs. did u get any codes ?? Quote Link to comment Share on other sites More sharing options...
R Holland Posted September 16, 2014 Author Report Share Posted September 16, 2014 The fuel fiter was replaced. The car is running fine now. I've been driving it back and forth to work for a month now. Read the entire thread for what I've done. Quote Link to comment Share on other sites More sharing options...
ron350 Posted September 16, 2014 Report Share Posted September 16, 2014 See if you can change the title to Fixed. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.