engine idles not so great in Park and Neutral
03-06-2007, 03:57 AM
#1
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engine idles not so great in Park and Neutral
Hello,
I have a 1987 Ford F150 Lariat 5 Litre, Engine 302, duel tank 2 door.
When I start the truck, it idles really low. When I put it in either reverse or drive, it seems to idle a bit better (sounds normal) but when I switch it to neutral or park, it will rev so low that it almost cuts out (sometimes does). It begins to idle a little higher after a bit but it still continues quite low.
People usually say it's the opposite (put it in Drive or Reverse and the engine's idle lowers).
When I have the hood up, and I turn off the engine, I hear a hissing sound like air escaping out of a hose (pressure? leak?) if that helps.
I can't see anything leaking or feel anything leaking because it's in between the engine and the fire wall (jammed way in there and I can't see in the back of it).
I've just replaced one of the gas tanks recently but that seems to be working alright.
Anyone every have this problem? Comments, suggestions?
Thanks.
quinn
I have a 1987 Ford F150 Lariat 5 Litre, Engine 302, duel tank 2 door.
When I start the truck, it idles really low. When I put it in either reverse or drive, it seems to idle a bit better (sounds normal) but when I switch it to neutral or park, it will rev so low that it almost cuts out (sometimes does). It begins to idle a little higher after a bit but it still continues quite low.
People usually say it's the opposite (put it in Drive or Reverse and the engine's idle lowers).
When I have the hood up, and I turn off the engine, I hear a hissing sound like air escaping out of a hose (pressure? leak?) if that helps.
I can't see anything leaking or feel anything leaking because it's in between the engine and the fire wall (jammed way in there and I can't see in the back of it).
I've just replaced one of the gas tanks recently but that seems to be working alright.
Anyone every have this problem? Comments, suggestions?
Thanks.
quinn
03-27-2007, 01:07 AM
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Location: Grand Junction Colorado
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Hey it sounds like possibly a vaccum leak. Try taking a little dish soap and mixing it with water and putting it into a spray bottle and spray over all your vaccum lines. You should be able to find a leak a lot easier that way if thats the case. Hope that helps man, have a good one
03-27-2007, 08:01 AM
#3
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Hello,
I have a 1987 Ford F150 Lariat 5 Litre, Engine 302, duel tank 2 door.
When I start the truck, it idles really low. When I put it in either reverse or drive, it seems to idle a bit better (sounds normal) but when I switch it to neutral or park, it will rev so low that it almost cuts out (sometimes does). It begins to idle a little higher after a bit but it still continues quite low.
People usually say it's the opposite (put it in Drive or Reverse and the engine's idle lowers).
When I have the hood up, and I turn off the engine, I hear a hissing sound like air escaping out of a hose (pressure? leak?) if that helps.
I can't see anything leaking or feel anything leaking because it's in between the engine and the fire wall (jammed way in there and I can't see in the back of it).
I've just replaced one of the gas tanks recently but that seems to be working alright.
Anyone every have this problem? Comments, suggestions?
Thanks.
quinn
I have a 1987 Ford F150 Lariat 5 Litre, Engine 302, duel tank 2 door.
When I start the truck, it idles really low. When I put it in either reverse or drive, it seems to idle a bit better (sounds normal) but when I switch it to neutral or park, it will rev so low that it almost cuts out (sometimes does). It begins to idle a little higher after a bit but it still continues quite low.
People usually say it's the opposite (put it in Drive or Reverse and the engine's idle lowers).
When I have the hood up, and I turn off the engine, I hear a hissing sound like air escaping out of a hose (pressure? leak?) if that helps.
I can't see anything leaking or feel anything leaking because it's in between the engine and the fire wall (jammed way in there and I can't see in the back of it).
I've just replaced one of the gas tanks recently but that seems to be working alright.
Anyone every have this problem? Comments, suggestions?
Thanks.
quinn
03-29-2007, 02:59 AM
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Re: idling problems...
Fords have a big problem with the throttle bodies gumming up. If you dont find a vacuum leak then try cleaning the throttle body. Use throttle body cleaner, not carb cleaner. From what you are describing the idle air motor may be partially stopped up. If there is no leaks and the throttle body cleaning dosent check the idle air control motor for being gummed up. Those older Fords don't give a live data stream without a breakout box so if none of this works we will have to get you to testing it the old fasioned way with multimeters.
quinn
04-25-2007, 01:16 AM
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problem solved (I think)
Have a look at the pic and you can see that there is a piece broken off where the hose was suppose to connect. I found a spare one in the junk yard and it seems to idle better when changing gears.
quinn
quinn