+- Madison Motorsports (https://forum.mmsports.org)
+-- Forum: Technical (https://forum.mmsports.org/forumdisplay.php?fid=4)
+--- Forum: Technical Discussion (https://forum.mmsports.org/forumdisplay.php?fid=11)
+--- Thread: high fives for engine questions (/showthread.php?tid=1490)
high fives for engine questions - REED - 12-16-2004
So ive recently noticed that when i start the explorer up it has a really jumpy idle. The engine starts fine and revs to app. 1500 rpm, then it drops to like 1000 and then it starts sputtering and jumps back up to around 2000, this continues and if i dont give it gas it will stall out. The fact that the engine can stall is the part that worries me the most. is this just cause it has been in the low teens when i start it in the morning or do i have something to be concerned with ?
i know that cold starts can be tough on engines, but this seems a little more dramatic than a "rough idle"
thanks for the input guys
- .RJ - 12-16-2004
Could be any number of things, most likely a sensor that regulates cold-start idle and/or fuel mixture.
- Mike - 12-17-2004
does it stop once the car is warm? if so, you have exactly the same issue i've had for the past two years. if so, don't worry about it unless you're throwing a cell or the car doesn't run right.
- PDenbigh - 12-17-2004
A few ideas come to mind:
Oxygen Sensor
TPS (Throttle Position Sensor)
IAC (Idle Air Controller (sensor...)
If you're really curious, take it to Autozone and have them hook up their computer to it. They'll do it for free, and you'll get a rough diagnostic. And guess what? They'd love to sell you whatever is broken :-)
good luck!
- white_2kgt - 12-17-2004
Interesting, my car just started doing this as well. I sent my chip back and had it reburned and it still is hunting for an idle. Maybe it is just the cold, I didn't drive my car last winter so I don't remember.
--chad
- JohnC - 12-17-2004
Also could be a vacuum leak - maybe a hose got brittle and cracked..
- Andy - 12-17-2004
Ford's have a cold start valve on their throttlebodies. Check that out. They're fairly inexpensive so something to consider. It could be a vacuum leak but I didn't think vacuum leaks were heat dependent. I could be wrong.
MichaelJComputer Wrote:does it stop once the car is warm? if so, you have exactly the same issue i've had for the past two years. if so, don't worry about it unless you're throwing a cell or the car doesn't run right.
Honda's have a fast idle valve. It's a mechanical valve that allows air to come in at cold start once the coolant warms up, it shuts the opening, and retain normal idle. But I'm sure you read that on the H-T board.
- JackoliciousLegs - 12-19-2004
could just be that your car is a POS
- Mike - 12-20-2004
JackoliciousLegs Wrote:could just be that your car is a POS
smokes yours hard though... i guess that could just be driver.