Cold Morning Startups
#1
01-20-2003, 06:07 PM
Join Date: May 2002
Location: Ann Arbor, MI
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Cold Morning Startups
Hopefully someone can help me out with this. When temp is very cold out, truck starts, then idle drops almost to a stall. I Have to give it gas for about two minutes to keep the idle up and the truck running. After the truck is warmed up a little, it runs OK and accellerates strong. The truck has been doing this periodically since the start of winter, but has recently started doing it every morning since the temps dropped to the teens over the last week. Lately, I have also noticed irratic idle at stop lights when the truck is warm.
I installed a new IAC a few days ago, but that did not solve the problem. Also, a week ago, the SES light came on - Codes: System Too Lean Bank 1 and System Too Lean Bank 2 (Pending). I checked the vac lines for any leaks, but seemed OK. Fuel filters have been changed regularly. Could I have a fuel supply problem, or would that show up under accelleration also?
The truck is a '99 V6 and has 120k miles. Any ideas what the problem might be? I'd appreciate your input before I start wasting money replacing sensors to identify the problem. Thanks alot!
-JM
I installed a new IAC a few days ago, but that did not solve the problem. Also, a week ago, the SES light came on - Codes: System Too Lean Bank 1 and System Too Lean Bank 2 (Pending). I checked the vac lines for any leaks, but seemed OK. Fuel filters have been changed regularly. Could I have a fuel supply problem, or would that show up under accelleration also?
The truck is a '99 V6 and has 120k miles. Any ideas what the problem might be? I'd appreciate your input before I start wasting money replacing sensors to identify the problem. Thanks alot!
-JM
#2
01-20-2003, 06:14 PM
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Hope you get a good answer. Unfortunately I don't have one but I do have the same problem. Don't have to goose it for 2 minutes. But, cold mornings it fires immediately then drops way low on idle for maybe 5 seconds. then comes back. I've had the truck since new and this is the first year it's happened. Thought of the IAC but since you already changed it out maybe not.
#3
01-20-2003, 07:38 PM
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How are the cap, rotor, wires and plugs? Find out if an ignition problem can gererate the code that you gave. I'd start there if you want to avoid replacing sensors (after waiting for more input on this post in case someone had a similar problem).
Since this happens first thing in the morning, It sounds like an air intake temp. sensor problem, speaking from experience on an older ('89 150 w/ a 300) that I used to own. Might also be an air charge sensor (if on your truck). Could also be cold start valve temp. switch. Lastly, I'd look into manifold temp.sensor, since you're idling rough at lights. Good luck.
Since this happens first thing in the morning, It sounds like an air intake temp. sensor problem, speaking from experience on an older ('89 150 w/ a 300) that I used to own. Might also be an air charge sensor (if on your truck). Could also be cold start valve temp. switch. Lastly, I'd look into manifold temp.sensor, since you're idling rough at lights. Good luck.