Help truck idles up to 2000 rpms
#1
#5
A smoke test - where you take a smoke machine and pressurize the inlet plenum for the truck. You then look for where smoke is coming out.
There's articles on using a fog machine to make a smoke machine. Also, if you, or a friend, is a smoker, there's always the "Big suck on a cigar, blow into a hose" method *grins*
But a super quick test - find the vacuum line going into the cab for the HVAC controls, disconnect it from the engine, and plug the engine side. See if it revs up then.
If it does, it's not vacuum, but the ECU activating the IAC ... and now it's time to check the IAC to see why it revs it that far.
RwP
There's articles on using a fog machine to make a smoke machine. Also, if you, or a friend, is a smoker, there's always the "Big suck on a cigar, blow into a hose" method *grins*
But a super quick test - find the vacuum line going into the cab for the HVAC controls, disconnect it from the engine, and plug the engine side. See if it revs up then.
If it does, it's not vacuum, but the ECU activating the IAC ... and now it's time to check the IAC to see why it revs it that far.
RwP
#6
A smoke test - where you take a smoke machine and pressurize the inlet plenum for the truck. You then look for where smoke is coming out.
There's articles on using a fog machine to make a smoke machine. Also, if you, or a friend, is a smoker, there's always the "Big suck on a cigar, blow into a hose" method *grins*
But a super quick test - find the vacuum line going into the cab for the HVAC controls, disconnect it from the engine, and plug the engine side. See if it revs up then.
If it does, it's not vacuum, but the ECU activating the IAC ... and now it's time to check the IAC to see why it revs it that far.
RwP
There's articles on using a fog machine to make a smoke machine. Also, if you, or a friend, is a smoker, there's always the "Big suck on a cigar, blow into a hose" method *grins*
But a super quick test - find the vacuum line going into the cab for the HVAC controls, disconnect it from the engine, and plug the engine side. See if it revs up then.
If it does, it's not vacuum, but the ECU activating the IAC ... and now it's time to check the IAC to see why it revs it that far.
RwP
#7
In which case, it's the inside hoses that are bad.
Loverly.
I suggest studying how to curse in at least three more languages, then plan on pulling the dash so you can pull the HVAC box so you can check all the vacuum plumbing. (Cursing doesn't make it go any smoother, but it's a nice emotional release *grins* ) Although, you may get lucky if you can lay on the floor looking up - you may find a unplugged hose. Try that first. Suggestion: If you pull it, order a heater core so you can replace that while it's out.
Although, you may get lucky - check the lines into the HVAC control unit, and see if they have any breaks there.
Now, just to recap and because I wasn't clear - the engine speed didn't change as you activated the A/C or heat with the line plugged, like it does when the line is connected, right?
RwP
Loverly.
I suggest studying how to curse in at least three more languages, then plan on pulling the dash so you can pull the HVAC box so you can check all the vacuum plumbing. (Cursing doesn't make it go any smoother, but it's a nice emotional release *grins* ) Although, you may get lucky if you can lay on the floor looking up - you may find a unplugged hose. Try that first. Suggestion: If you pull it, order a heater core so you can replace that while it's out.
Although, you may get lucky - check the lines into the HVAC control unit, and see if they have any breaks there.
Now, just to recap and because I wasn't clear - the engine speed didn't change as you activated the A/C or heat with the line plugged, like it does when the line is connected, right?
RwP
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#8
In which case, it's the inside hoses that are bad.
Loverly.
I suggest studying how to curse in at least three more languages, then plan on pulling the dash so you can pull the HVAC box so you can check all the vacuum plumbing. (Cursing doesn't make it go any smoother, but it's a nice emotional release *grins* ) Although, you may get lucky if you can lay on the floor looking up - you may find a unplugged hose. Try that first. Suggestion: If you pull it, order a heater core so you can replace that while it's out.
Although, you may get lucky - check the lines into the HVAC control unit, and see if they have any breaks there.
Now, just to recap and because I wasn't clear - the engine speed didn't change as you activated the A/C or heat with the line plugged, like it does when the line is connected, right?
RwP
Loverly.
I suggest studying how to curse in at least three more languages, then plan on pulling the dash so you can pull the HVAC box so you can check all the vacuum plumbing. (Cursing doesn't make it go any smoother, but it's a nice emotional release *grins* ) Although, you may get lucky if you can lay on the floor looking up - you may find a unplugged hose. Try that first. Suggestion: If you pull it, order a heater core so you can replace that while it's out.
Although, you may get lucky - check the lines into the HVAC control unit, and see if they have any breaks there.
Now, just to recap and because I wasn't clear - the engine speed didn't change as you activated the A/C or heat with the line plugged, like it does when the line is connected, right?
RwP
#9
Did you disconnect before, or after, the check valve? However, easy to test - disconnect after the check valve, does it rev like that? Plug it, does it drop back down?
And when it's down, does manipulating the HVAC controls cause it to rev up and down?
The sticker in my head about it being the check valve is that it takes manipulating the HVAC controls to cause it to rev like that. I'd not expect it to go to 2,000 RPM ... but another hint is the "heater core isn't even a year old BC I changed it myself already lol." At what point did it start the revving? I'd double check the vacuum lines.
Having had the dash out you're familiar with why I said "Loverly" and to study up how to curse in at least three more languages *grins*
But that also means you can probably pinpoint where the vacuum lines ARE ...
Check the FSM for how the vacuum lines are activated, and see what plan best matches what manipulation of controls causes the engine revs, and you'll have zeroed in on where the leak could be.
RwP
And when it's down, does manipulating the HVAC controls cause it to rev up and down?
The sticker in my head about it being the check valve is that it takes manipulating the HVAC controls to cause it to rev like that. I'd not expect it to go to 2,000 RPM ... but another hint is the "heater core isn't even a year old BC I changed it myself already lol." At what point did it start the revving? I'd double check the vacuum lines.
Having had the dash out you're familiar with why I said "Loverly" and to study up how to curse in at least three more languages *grins*
But that also means you can probably pinpoint where the vacuum lines ARE ...
Check the FSM for how the vacuum lines are activated, and see what plan best matches what manipulation of controls causes the engine revs, and you'll have zeroed in on where the leak could be.
RwP
#10
Did you disconnect before, or after, the check valve? However, easy to test - disconnect after the check valve, does it rev like that? Plug it, does it drop back down?
And when it's down, does manipulating the HVAC controls cause it to rev up and down?
The sticker in my head about it being the check valve is that it takes manipulating the HVAC controls to cause it to rev like that. I'd not expect it to go to 2,000 RPM ... but another hint is the "heater core isn't even a year old BC I changed it myself already lol." At what point did it start the revving? I'd double check the vacuum lines.
Having had the dash out you're familiar with why I said "Loverly" and to study up how to curse in at least three more languages *grins*
But that also means you can probably pinpoint where the vacuum lines ARE ...
Check the FSM for how the vacuum lines are activated, and see what plan best matches what manipulation of controls causes the engine revs, and you'll have zeroed in on where the leak could be.
RwP
And when it's down, does manipulating the HVAC controls cause it to rev up and down?
The sticker in my head about it being the check valve is that it takes manipulating the HVAC controls to cause it to rev like that. I'd not expect it to go to 2,000 RPM ... but another hint is the "heater core isn't even a year old BC I changed it myself already lol." At what point did it start the revving? I'd double check the vacuum lines.
Having had the dash out you're familiar with why I said "Loverly" and to study up how to curse in at least three more languages *grins*
But that also means you can probably pinpoint where the vacuum lines ARE ...
Check the FSM for how the vacuum lines are activated, and see what plan best matches what manipulation of controls causes the engine revs, and you'll have zeroed in on where the leak could be.
RwP