Engine Idle
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Engine Idle
I have an idle problem. My 4.9L, '89 F150 surges then, after a minute or two, settles down to a nice smooth RPM (750). So, I've been searching other threads to find out more about the MAFS and I can't find anything about it in my blue, Ford Manuals. I seem to think if I can clean the throttle body assy. maybe the engine will idle smooth all the time??
I don't know where the MAFS is. Is it in the Throttle Body?
Sometimes, the idle is so up and down, that it dies. Usually it just goes from about 500RPMs up to about 900 and back and forth until it finds 750. I read in one thread, a while back, that the MAFS is delicate. Maybe I should have a pro do this or is this something I can do. I'm not a stranger to that engine. (I can pull my injectors in 20 minutes flat).
Can I use spray carb cleaner to clean the throttle body while the motor is running or do I have to remove it and scrub it like crazy to do the job right?
I don't know where the MAFS is. Is it in the Throttle Body?
Sometimes, the idle is so up and down, that it dies. Usually it just goes from about 500RPMs up to about 900 and back and forth until it finds 750. I read in one thread, a while back, that the MAFS is delicate. Maybe I should have a pro do this or is this something I can do. I'm not a stranger to that engine. (I can pull my injectors in 20 minutes flat).
Can I use spray carb cleaner to clean the throttle body while the motor is running or do I have to remove it and scrub it like crazy to do the job right?
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Joined: Dec 2001
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From: Louisville,Ky.
You do not have a MAF. I would suspect the IAC (Idle Aic Contol) motor. It is the round cylinder on the throttlebody that is held on by 2 8mm bolts and has 2 wires going to the plug.
You can clean it and it may work for awhile, but I would go ahead and replace it, they don't cost that much.
Jimmy
You can clean it and it may work for awhile, but I would go ahead and replace it, they don't cost that much.
Jimmy
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The only round cylinder on the throttle body is the Air Bypass Valve. I checked the manuals again and I didn't see anything called an Idle Air Control. Two bolts and a plug, hey, I can do that!
I thought I had an MAFS.
I'll replace the ABV if you think that will help. Thanks lxman1
I thought I had an MAFS.
I'll replace the ABV if you think that will help. Thanks lxman1
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Since my last message, I've learned a few things. And they lead to more questions. Trying to get this figured out, I would like to know what does ECA stand for and by disconnecting the battery negative terminal, does that erase the ECA memory?
Also, how does one perform a "memory re-learn"? I've read that if I replace my IAC, erase the ECA memory and do this re-learn business, I should be close to solving this idle problem.
Lastly, my coolant temp sending unit is out. I see that I have to replace that, as well. This just happened, but the idle problem has been going on for much longer.
So, how does all this sound?
Also, how does one perform a "memory re-learn"? I've read that if I replace my IAC, erase the ECA memory and do this re-learn business, I should be close to solving this idle problem.
Lastly, my coolant temp sending unit is out. I see that I have to replace that, as well. This just happened, but the idle problem has been going on for much longer.
So, how does all this sound?
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Joined: Dec 2001
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From: Louisville,Ky.
Different name for the same part. IAC, ABV are one in the same. It controls the idle speed by letting air bypass the throttle plate.
The temp sender is the one that inly has 1 wire. The one with 2 wires is the temp sensor for the ECM (ECA) Electronic Control Module.
I don't think that you need to reset the computer, it will still adapt to the new parts.
Jimmy
The temp sender is the one that inly has 1 wire. The one with 2 wires is the temp sensor for the ECM (ECA) Electronic Control Module.
I don't think that you need to reset the computer, it will still adapt to the new parts.
Jimmy
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From: Northwest Fl
Originally Posted by Hydro
I have an idle problem. My 4.9L, '89 F150 surges then, after a minute or two, settles down to a nice smooth RPM (750). ....
...Sometimes, the idle is so up and down, that it dies.
...Sometimes, the idle is so up and down, that it dies.
