idle problems '87 f150 inline 6
11-30-2007, 07:42 PM
#1
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idle problems '87 f150 inline 6
I just bought this truck and really got a great deal, but i have a few problems. Starts great, runs grreat until it warms up, then the problems start. At idle it will start rising and droping rpm's eraticly at times and then it runs fine then runs at a high idle.
Driving the truck with the foot off the pedal then lightly pressing the idle will drop back sometimes dying!
Idle air control valve or what ?
Driving the truck with the foot off the pedal then lightly pressing the idle will drop back sometimes dying!
Idle air control valve or what ?
11-30-2007, 09:59 PM
#3
Senior Member
Welcome to the site!
Any fault codes? Is the 'check engine' light on? Does it self-test on start-up? Standard recommendation is to get any codes pulled first to reduce the amount of guesswork. If you don't have a code reader, AutoZone does this for free, except in CA as I understand it.
Idle Air Control is a good bet - these have a tendency to crud up. Easy enough to pull off and clean out with carb cleaner. While you're at it, inspect the main throttle body butterflies to ensure they seal off good when closed - they tend to crud up also.
Another possibility is the EGR valve, but should have thrown a code unless there's something unusual, like a split in the exhaust gas tubing to the valve.
You've got a solid truck with a near-indestructible engine. Be patient and work through the problem - it should have many happy driving miles left in it.
Let us know what you find.
Any fault codes? Is the 'check engine' light on? Does it self-test on start-up? Standard recommendation is to get any codes pulled first to reduce the amount of guesswork. If you don't have a code reader, AutoZone does this for free, except in CA as I understand it.
Idle Air Control is a good bet - these have a tendency to crud up. Easy enough to pull off and clean out with carb cleaner. While you're at it, inspect the main throttle body butterflies to ensure they seal off good when closed - they tend to crud up also.
Another possibility is the EGR valve, but should have thrown a code unless there's something unusual, like a split in the exhaust gas tubing to the valve.
You've got a solid truck with a near-indestructible engine. Be patient and work through the problem - it should have many happy driving miles left in it.
Let us know what you find.
12-02-2007, 11:24 AM
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codes no lite
I have thought about that but my check engine light is not lit. But still I wonder If they may be codes that would show up?
New plugs, cap and rotor are on the list of things to do today among the idle air control valve cleaning again. More checking on vacuum leaks
and intake manifold leaks.
Thanks, I'll let you know later.
New plugs, cap and rotor are on the list of things to do today among the idle air control valve cleaning again. More checking on vacuum leaks
and intake manifold leaks.
Thanks, I'll let you know later.
12-02-2007, 11:38 AM
#5
No Pain, No Pain!
Welcome to the site!
Any fault codes? Is the 'check engine' light on? Does it self-test on start-up? Standard recommendation is to get any codes pulled first to reduce the amount of guesswork. If you don't have a code reader, AutoZone does this for free, except in CA as I understand it.
Idle Air Control is a good bet - these have a tendency to crud up. Easy enough to pull off and clean out with carb cleaner. While you're at it, inspect the main throttle body butterflies to ensure they seal off good when closed - they tend to crud up also.
Another possibility is the EGR valve, but should have thrown a code unless there's something unusual, like a split in the exhaust gas tubing to the valve.
You've got a solid truck with a near-indestructible engine. Be patient and work through the problem - it should have many happy driving miles left in it.
Let us know what you find.
Any fault codes? Is the 'check engine' light on? Does it self-test on start-up? Standard recommendation is to get any codes pulled first to reduce the amount of guesswork. If you don't have a code reader, AutoZone does this for free, except in CA as I understand it.
Idle Air Control is a good bet - these have a tendency to crud up. Easy enough to pull off and clean out with carb cleaner. While you're at it, inspect the main throttle body butterflies to ensure they seal off good when closed - they tend to crud up also.
Another possibility is the EGR valve, but should have thrown a code unless there's something unusual, like a split in the exhaust gas tubing to the valve.
You've got a solid truck with a near-indestructible engine. Be patient and work through the problem - it should have many happy driving miles left in it.
Let us know what you find.
Autozone does check your engine codes for free, but only on 96 and newer vehicles that have the adaptor under the dash, otherwise, you will need to take it to an emissions service center. They can hook it up to their computer and tell you what is wrong. This will probably cost you around $70-80 bucks for the computer check.
12-02-2007, 12:16 PM
#6
Senior Member
Hmmm - didn't know that about Autozone - the model year limitations. I suppose that covers the OBD-II series only, not the OBD-I that our generation trucks have.
Suggest to look for an OBD-I code reader - I'm hearing that one can be picked up for $20-$30, if you can find one. A little easier on the wallet than having a shop pull them for you.
As for the 'check engine' light - it should be lit if there is an active fault. It would be good to look at any historical faults with the code reader. Also, have to be sure the light is good - the reason for the question about seeing it during the self-test at start-up.
Suggest to look for an OBD-I code reader - I'm hearing that one can be picked up for $20-$30, if you can find one. A little easier on the wallet than having a shop pull them for you.
As for the 'check engine' light - it should be lit if there is an active fault. It would be good to look at any historical faults with the code reader. Also, have to be sure the light is good - the reason for the question about seeing it during the self-test at start-up.