The Car - 99' GT 4.6L Auto, 4.10's in rear, modded/piggyback chip (speedo/ boosts Idle/shift points higher/ stronger shift) ~120,000 miles. This used to be my car and I've given it to my sister since I purchased my truck, however, I still play around with it some and help her out when she has any problems with it. Enough backstory. The Problem - When the car goes under a light load, anything from dropping it into reverse, to slowing pulling down a flat road at normal speed, it starts hiccuping and eventually dies. The problem is intermittent as it doesn't die ALL the time, just happens a good bit. We live in the mountains and it is more noticable when you are coming out of a curve and accelerate normally, seems like it's missing and then revs high and dies. If I gun it I have absolutely no problems, tranny locks up just fine, can squeal tires all the way through third, and the car doesn't die (or even miss) at all. I've been told that a clogged catalytic converter sounds like the problem but I'm leaning toward a fuel problem (pump/filter) but it seems to idle fine, as long as it is not in gear. A few years ago I had some cooling system problems and it did something simlar but would die once it reached temp... this happens at any temp so I've kinna disregarded that. Anybody have a similar experience? Any help is greatly appreciated! Thanks, Trey
Where is your idle at? Sounds like your iac may not be kicking in soon enough and allowing the car to die.
Normal Idle of this car is set at ~ 1100 RPM. The car is dying between 1700 and 3000. Any tests or remedies I can try with the IAC problem you mentioned?
