99 Explorer Engine light code
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Senior User
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99 Explorer Engine light code
The Check Engine light came on in my wife's explorer. It has the 4L SOHC engine. Had Autozone scan the codes. Scanner reported Lean condition on Banks 1 and 2.
I replaced the IAC a few weeks ago due to a cold start stalling problem. Since then, cold starts have been fine. Now, during warm starts it idles fast for a few seconds, drops to 500 rpm, stumbles and stalls if I don't tap the gas. Any suggestions on where to start?
I replaced the IAC a few weeks ago due to a cold start stalling problem. Since then, cold starts have been fine. Now, during warm starts it idles fast for a few seconds, drops to 500 rpm, stumbles and stalls if I don't tap the gas. Any suggestions on where to start?
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Check for broken or loose vacuum lines. If nothing obvious, then spray carb cleaner around the intake mouting surface when cold while running. If you notice an idle change when you're spraying, replace the intake gaskets (Rubber-band looking o-ring things)...
If no idle change found, clean the MAF, clear codes and drive it.
If light comes back on later on, replace intake gaskets anyway.
If no idle change found, clean the MAF, clear codes and drive it.
If light comes back on later on, replace intake gaskets anyway.
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It's usually the uppers, but kind of not smart to not do the lowers while you're in there. Once you have the upper off, it's pretty much a matter of pulling the fuel rail and a few bolts to get the lower off.
It's not the worst job, but if you've never done it before plan on it being an all day thing.
Good luck.
It's not the worst job, but if you've never done it before plan on it being an all day thing.
Good luck.
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Joined: Oct 2006
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I am pretty sure you will find that you have a vacuum leak. It is a very common code for Fords in general. In the Sport and Sport Trac era it is the elbow that goes into the near the front of the on the passengers side.
If you were to follow the the line/elbow back you would find it is attached to the PCV.
The hose cracks on the bottom so you normally have to pull it off to see the crack.
If you were to follow the the line/elbow back you would find it is attached to the PCV.
The hose cracks on the bottom so you normally have to pull it off to see the crack.
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I drove the Explorer tonight. No issue when starting if the engine is cold. If the engine is warm, the rpms start high (roughly 1500 rpm) and drop to 500 and then the engine stalls. If I tap the accelerator just before the engine starts to stall, rpms increase and stabilize without having to use the accelerator. My guess is that this rules out a vacuum or intake leak as it should be an issue warm or cold and shouldn't go away if I tap the accelerator. Correct or am I off on this one?
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You're off... in the old days you'd be more on the money, but these newer vehicle are so dependant on computer controls... well I'll just say the computer is so good at compensating for problems, sometimes it can mask vacuum leak symptoms all together.
We're also talking about a small, small leak, just enough to throw off the proper air metering to maintain proper air/fuel ratios.
We're also talking about a small, small leak, just enough to throw off the proper air metering to maintain proper air/fuel ratios.
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