2000 RPM idle! HELP!!!
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2000 RPM idle! HELP!!!
Well here is the story. Bought a 95 F-150 truck that had a 4.9 with a thrown rod. We got another engine, and now the idle will not go under 2k RPM.
We sprayed all around the engine to look for changes in the idle. Nothing
Disconnected the IAC nothing, swapped the IAC with another (no clue if either are good).
Pulled vacuum lines and the idle goes down???
Base timing set at 10* with SPOUT removed.
Put pressure on the system and couldn't hear a noise of a leak.
With all the checking I did I found nothing. I did block the small holes in the throttle blades, and it did lower the idle about 500.
Have to double check for codes, but the last time I ran them it was fine. I haven't blocked the TB to see if it will still run.
95 F-150 5-speed
We sprayed all around the engine to look for changes in the idle. Nothing
Disconnected the IAC nothing, swapped the IAC with another (no clue if either are good).
Pulled vacuum lines and the idle goes down???
Base timing set at 10* with SPOUT removed.
Put pressure on the system and couldn't hear a noise of a leak.
With all the checking I did I found nothing. I did block the small holes in the throttle blades, and it did lower the idle about 500.
Have to double check for codes, but the last time I ran them it was fine. I haven't blocked the TB to see if it will still run.
95 F-150 5-speed
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Could be a couple things.
Try this first.
If when you disconnected the vacuum lines, I assume from the vac tree (?), you plugged all open ports and the idle dropped to normal, check the vacuum lines themselves, as one of the hard vac lines is likely cracked or melted. Look beside the valve cover and behind, going to the TAB and TAD.
Try this only after youve verified all vac lines are in good condition.
If you find nothing there, then its possible, your TAB solenoid is bad.
Check the connections at the TAB and TAD solenoids (back of the valve cover).
Seems like what could be happening, is the bypass valve aka egr valve is open when it shouldnt be. Quick way to see, connect all vacuum lines where they should be. Then remove the vacuum line from the EGR valve and plug the rubber hose or hold it closed, if your idle drops, its the TAB.
Try this first.
If when you disconnected the vacuum lines, I assume from the vac tree (?), you plugged all open ports and the idle dropped to normal, check the vacuum lines themselves, as one of the hard vac lines is likely cracked or melted. Look beside the valve cover and behind, going to the TAB and TAD.
Try this only after youve verified all vac lines are in good condition.
If you find nothing there, then its possible, your TAB solenoid is bad.
Check the connections at the TAB and TAD solenoids (back of the valve cover).
Seems like what could be happening, is the bypass valve aka egr valve is open when it shouldnt be. Quick way to see, connect all vacuum lines where they should be. Then remove the vacuum line from the EGR valve and plug the rubber hose or hold it closed, if your idle drops, its the TAB.
Thread Starter
|
New User
Joined: Oct 2008
Posts: 4
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Could be a couple things.
Try this first.
If when you disconnected the vacuum lines, I assume from the vac tree (?), you plugged all open ports and the idle dropped to normal, check the vacuum lines themselves, as one of the hard vac lines is likely cracked or melted. Look beside the valve cover and behind, going to the TAB and TAD.
Try this only after youve verified all vac lines are in good condition.
If you find nothing there, then its possible, your TAB solenoid is bad.
Check the connections at the TAB and TAD solenoids (back of the valve cover).
Seems like what could be happening, is the bypass valve aka egr valve is open when it shouldnt be. Quick way to see, connect all vacuum lines where they should be. Then remove the vacuum line from the EGR valve and plug the rubber hose or hold it closed, if your idle drops, its the TAB.
Try this first.
If when you disconnected the vacuum lines, I assume from the vac tree (?), you plugged all open ports and the idle dropped to normal, check the vacuum lines themselves, as one of the hard vac lines is likely cracked or melted. Look beside the valve cover and behind, going to the TAB and TAD.
Try this only after youve verified all vac lines are in good condition.
If you find nothing there, then its possible, your TAB solenoid is bad.
Check the connections at the TAB and TAD solenoids (back of the valve cover).
Seems like what could be happening, is the bypass valve aka egr valve is open when it shouldnt be. Quick way to see, connect all vacuum lines where they should be. Then remove the vacuum line from the EGR valve and plug the rubber hose or hold it closed, if your idle drops, its the TAB.
Alex.hump@yahoo.com
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The idle starts off low then goes to 2000.
The throttle return spring is fine.
When we cover the throttle body it will still idle. The upper intake manifold gasket seems like it needs to be replaced. We plugged the egr nothing, pulled all the vacuum lines, nothing...
Could it pass without the smog pump???
The throttle return spring is fine.
When we cover the throttle body it will still idle. The upper intake manifold gasket seems like it needs to be replaced. We plugged the egr nothing, pulled all the vacuum lines, nothing...
Could it pass without the smog pump???
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