IDLE
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Laughing Gas
Joined: Feb 2011
Posts: 1,147
Likes: 6
From: Vine Grove KY
will do right now, thanks
Thread Starter
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Laughing Gas
Joined: Feb 2011
Posts: 1,147
Likes: 6
From: Vine Grove KY
OK. I got different results this time doing the KOER test. When prompted I hit the throttle wide open. After that this is what the codes were.
44
34
edit: I set the idle screw before this test to were the engine would just die with no IAC hooked up.
44
34
edit: I set the idle screw before this test to were the engine would just die with no IAC hooked up.
Thread Starter
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Laughing Gas
Joined: Feb 2011
Posts: 1,147
Likes: 6
From: Vine Grove KY
I have aftermarket headers. I did weld in the o2 sensor bung and placed the o2 sensor in the passenger side. The o2 sensor was new last year with the rebuild, and so was the map sensor. EGR is hooked up. AIR stuff deleted.
Moderator
Joined: Nov 2007
Posts: 22,415
Likes: 92
From: Denver Metro Area, CO
Is your engine warmed up? I'm sorry, i should have said earlier to warm it up to operating temperature before doing this test.
These things are related to the Emissions Control equipment...
44 = Thermactor Air Injection system inoperative (Right side).
34 = PFE or EVP circuit has intermittently failed above the closed limit of 0.67 volts.
Has your emissions stuff been removed?
These things are related to the Emissions Control equipment...
44 = Thermactor Air Injection system inoperative (Right side).
34 = PFE or EVP circuit has intermittently failed above the closed limit of 0.67 volts.
Has your emissions stuff been removed?
Thread Starter
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Laughing Gas
Joined: Feb 2011
Posts: 1,147
Likes: 6
From: Vine Grove KY
Is your engine warmed up? I'm sorry, i should have said earlier to warm it up to operating temperature before doing this test.
These things are related to the Emissions Control equipment...
44 = Thermactor Air Injection system inoperative (Right side).
34 = PFE or EVP circuit has intermittently failed above the closed limit of 0.67 volts.
Has your emissions stuff been removed?
These things are related to the Emissions Control equipment...
44 = Thermactor Air Injection system inoperative (Right side).
34 = PFE or EVP circuit has intermittently failed above the closed limit of 0.67 volts.
Has your emissions stuff been removed?
Could my problem be that the IAC is just getting old and functions, but not really great like it should?
Moderator
Joined: Nov 2007
Posts: 22,415
Likes: 92
From: Denver Metro Area, CO
These codes are the air pump and EGR valve, I'm guessing somebody thought they could make it "run better" and wanted to "wake up the engine" or some such bullchit.
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During the KOER test, the computer raises & lowers the engine speed; if it can't do that, it will certainly tell you so.
If the computer doesn't know about the problem, then it's most likely going to be a fuel or ignition issue. For example, I don't think an OBD1 system knows anything about the fuel pressure or the spark quality, nor will it necessarily know the ignition module has failed.
So I would begin there... check fuel pressure & output rate at the engine I guess is where I'd begin.
I'll re-read this thread tomorrow and see what the symptoms are and see what the book sez.
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During the KOER test, the computer raises & lowers the engine speed; if it can't do that, it will certainly tell you so.
If the computer doesn't know about the problem, then it's most likely going to be a fuel or ignition issue. For example, I don't think an OBD1 system knows anything about the fuel pressure or the spark quality, nor will it necessarily know the ignition module has failed.
So I would begin there... check fuel pressure & output rate at the engine I guess is where I'd begin.
I'll re-read this thread tomorrow and see what the symptoms are and see what the book sez.
Thread Starter
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Laughing Gas
Joined: Feb 2011
Posts: 1,147
Likes: 6
From: Vine Grove KY
NEW fuel pumps in tank and on rail. New fuel pressure regulator. New fuel filter.
New distributor cap and rotor. New MSD Blaster coil. New plug wires. New platinum plugs. base timing set to 12 BTDC (yes I set it with SPOUT plug unplugged). I thought advancing the timing might help with the headers and mild porting on the heads. 10 BTDC or 14 BTDC doesn't make any difference, it still has erratic idle. Rebuilt the distributor last week with new pick-up and TFI module.
New distributor cap and rotor. New MSD Blaster coil. New plug wires. New platinum plugs. base timing set to 12 BTDC (yes I set it with SPOUT plug unplugged). I thought advancing the timing might help with the headers and mild porting on the heads. 10 BTDC or 14 BTDC doesn't make any difference, it still has erratic idle. Rebuilt the distributor last week with new pick-up and TFI module.
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Moderator
Joined: Nov 2007
Posts: 22,415
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From: Denver Metro Area, CO
New doesn't always mean good. Do you have good fuel pressure at the engine? The fuel pump in my DD Tempo was failing, putting out half the pressure it should have been and one of the symptoms was a bad idle.
I don't think the computer will know of dirty or malfunctioning injectors, either.
I don't think the computer will know of dirty or malfunctioning injectors, either.
Thread Starter
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Laughing Gas
Joined: Feb 2011
Posts: 1,147
Likes: 6
From: Vine Grove KY
New doesn't always mean good. Do you have good fuel pressure at the engine? The fuel pump in my DD Tempo was failing, putting out half the pressure it should have been and one of the symptoms was a bad idle.
I don't think the computer will know of dirty or malfunctioning injectors, either.
I don't think the computer will know of dirty or malfunctioning injectors, either.
When I started up the truck a minute ago it reved up and then went really low in rpms, then came back to life and idled pretty good. Its a sudden change from open throttle to closed throttle that it doesn't like very much.
Moderator
Joined: Nov 2007
Posts: 22,415
Likes: 92
From: Denver Metro Area, CO
I don't know anything about injectors - how to test them, how to clean them, etc. - you might google it.
I'm also not a fan of snake oil, there is only one that I would consider using, something called BG 44K I believe.
Might get yourself a vacuum gauge and see what it reports, too.
But I'm going to begin with the basics - what is the fuel pressure at the engine?
I'll see tomorrow what I can find for pinpoint tests for the IAC.
EDIT: If the IAC were failing, I'd expect the computer to report that it cannot control the idle speed.
I'm also not a fan of snake oil, there is only one that I would consider using, something called BG 44K I believe.
Might get yourself a vacuum gauge and see what it reports, too.
But I'm going to begin with the basics - what is the fuel pressure at the engine?
I'll see tomorrow what I can find for pinpoint tests for the IAC.
EDIT: If the IAC were failing, I'd expect the computer to report that it cannot control the idle speed.
Postmaster
Joined: Jan 2012
Posts: 3,462
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From: Richmond
I'm a fan of sea foam. But only when it's the right conditions, and used correctly.
Only thing I know about injectors is testing the pulse to them, and checking their flow outside of the truck. You can have a local guy that knows his stuff bench test them for you.
Chris- I'm wondering if the mechanical valve itself inside the IAC is failing. So the computer sends power to it and it gets there. "Oh, everything is okay." but inside it's lagging, sticking, etc.
Only thing I know about injectors is testing the pulse to them, and checking their flow outside of the truck. You can have a local guy that knows his stuff bench test them for you.
Chris- I'm wondering if the mechanical valve itself inside the IAC is failing. So the computer sends power to it and it gets there. "Oh, everything is okay." but inside it's lagging, sticking, etc.
Moderator
Joined: Nov 2007
Posts: 22,415
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From: Denver Metro Area, CO
I haven't yet re-read this thread to read the symptoms, but here is how mine acted....
Sometimes, but not all the time, the car would want to die while sitting at a stop light. The computer would usually catch it before it died and "step on the gas pedal" for a second or so. The engine would speed up and recover, then begin its downward trend again.
There isn't a valve in the IAC, it's just a motor and some gears that extend/retract a plunger that pushes on the throttle.
During the KOER test, the computer looks at the idle speed and tries to control it with the IAC. If it can't do this it'll fail the test and report it (Code 13 or some such). I would expect there is a code it'd use for this in normal driving, too.
Sometimes, but not all the time, the car would want to die while sitting at a stop light. The computer would usually catch it before it died and "step on the gas pedal" for a second or so. The engine would speed up and recover, then begin its downward trend again.
There isn't a valve in the IAC, it's just a motor and some gears that extend/retract a plunger that pushes on the throttle.
During the KOER test, the computer looks at the idle speed and tries to control it with the IAC. If it can't do this it'll fail the test and report it (Code 13 or some such). I would expect there is a code it'd use for this in normal driving, too.
Moderator
Joined: Nov 2007
Posts: 22,415
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From: Denver Metro Area, CO
I should clarify.... the IAC in my Tempo with CFI pushes on the throttle and doesn't have any valves. I just looked at the IAC on my bro's 1993 Taurus SHO and I'm not sure how it operates. Well, it's a motor, but I don't know what it controls or does or how it does it, it's attached to some tubing and does something inside somehow.
For IAC diagnostics on this truck, I need to know which engine we have here....
For IAC diagnostics on this truck, I need to know which engine we have here....