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High Idle - LH2.2 Throttle body, Base Idle and TPS questions

smeha

smeha

Tranny Whisperer
Joined
Mar 3, 2017
Location
California
Hello TBers,
The car is 1988 245DL LH2.2 Chrysler crap box.
Long story short got high RPM problem. Extra 300-400 on Idle/Neutral and extra 100-200 in Drive/Reverse.
After all the tests with IAC and vacuum leaks check it seems like throttle body or TPS giving me some.
1) Is there is a correct way or something special to replace Throttle Position Sensor? Would I need to adjust any mixture/base idle/butterfly opening?
2) If I need to adjust base idle, someone tell me how? Internet giving me headache of different answers.
3) My base idle screw is a bit loose(and most certainly I might have screwed it few times on accident when reaching IAC and other stuff), is it supposed to be tighten or something more proper?

Basically the question: In order to take apart throttle body and in addition replace TPS. What kind of problems and adjusting after I'm looking forward to? Any tricks or intense problems are waiting for me?

Thank you
 
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Disconnect the IAC, set idle to 750 rpms with idle screw, reconnect IAC. I think this is the correct procedure. The IAC can only compensate for so much, if the idle screw is backed out too far it can't control the idle even when it closes all the way.
 
VB242 said:
Disconnect the IAC, set idle to 750 rpms with idle screw, reconnect IAC. I think this is the correct procedure. The IAC can only compensate for so much, if the idle screw is backed out too far it can't control the idle even when it closes all the way.
Click to expand...

The procedures I read are way different from what you are telling me. I think you mixing it with some other LH version or a car at all.

Also i meant to say High RPM and not just idle.
Extra 300-400 on Idle/Neutral and extra 100-200 in Drive/Reverse.
 
There is a 2 wire connector around the coil area with pink wire and a blue wire, (something like that). You will need to ground the blue wire which will make the IAC close fully. then you set idle to 740ish or whatever. It just got really cold where I live so I've been noticing my idle hanging higher intermittently... I think the IAC is just kinda hanging open sometimes. If you give it a quick rev most the time it will settle down. It bothers me but I haven't swapped in another IAC yet. Check for intake vacuum leaks too... With the wire grounded you should be able to set the idle really low, like 500rpm... If not you have air coming in somewhere, or the IAC is not closing fully.
 
intothelabyrinth said:
There is a 2 wire connector around the coil area with pink wire and a blue wire, (something like that). You will need to ground the blue wire which will make the IAC close fully. then you set idle to 740ish or whatever. It just got really cold where I live so I've been noticing my idle hanging higher intermittently... I think the IAC is just kinda hanging open sometimes. If you give it a quick rev most the time it will settle down. It bothers me but I haven't swapped in another IAC yet. Check for intake vacuum leaks too... With the wire grounded you should be able to set the idle really low, like 500rpm... If not you have air coming in somewhere, or the IAC is not closing fully.
Click to expand...

Thank you about connector resetting base idle. Although, that doesn't answer my main question about installation of new TPS and do I really need to set the base idle or not after replacing TPS.

I DO APPRECIATE IT. However, IAC been replaced with fully pry opened, cleaned and tested including shorting it to open and close on the bench. Still the same, so I know it's something else. I've checked vacuum leaks already. I would like some insight on my questions in post #1. I added the simplified question :) Thanks.
 
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I've never replaced a tps, so I can't help you there. I would recommend though that you test it first. Listen for it clicking when opening and closing, and use a multi meter to test that it indeed opens and closes the switch... Someone else can chime in on walking you through the replacement although I would be surprised if a detailed how to doesn't already exist somewhere.
 
intothelabyrinth said:
I've never replaced a tps, so I can't help you there. I would recommend though that you test it first. Listen for it clicking when opening and closing, and use a multi meter to test that it indeed opens and closes the switch... Someone else can chime in on walking you through the replacement although I would be surprised if a detailed how to doesn't already exist somewhere.
Click to expand...

I found few ways with twisting and so on on TPS replacement. They are annoyingly written or i'm just an idiot. It's clicking spool tensioned and clicking released. I think the electronics are fried. Might test it before replacement with multimeter, but I was thinking of replacing it anyways since I'm going to completely take apart throttle body and replace all gaskets, o rings and so on.
 
If you are adjusting your AMM you will know for sure if the tps is working or not. Your light will never blink if the tps doesn't close and signal the ecu that it is time to idle.
 
intothelabyrinth said:
If you are adjusting your AMM you will know for sure if the tps is working or not. Your light will never blink if the tps doesn't close and signal the ecu that it is time to idle.
Click to expand...

Judging by high rpm it and proper clicking from throttle it seems it doesn't tell when it's operating and keeping iac valve open or my butterfly stuck
 
I wouldn't just assume that. I also wouldn't suspect that. The IAC can hang open just because it's old and crappy, even after being cleaned and lubed. Just because the TPS clicks, doesn't mean the switch is working. Check it with a multi-meter. It goes open when open, and closed when closed...
 
intothelabyrinth,
You have been a big help, I ordered few days ago TPS all the gaskets and seals for throttle body.
Once it all come, I will disassemble it fully, clean and see what's up.
I'm pretty sure TPS doesn't work simply because I opened snorkel air pipe and it seems closing to me.
Someone was telling about female contacts sometimes doesn't want to get on TPS, so I shall see that too when all the parts arrive.
Thank you
 
Google search: "Volvo 240 TPS adjustment"

First result:

brickboard.com said:
The proper Volvo spec for *adjusting* the TPS on LH-Jetronic cars (as per TSB) is as follows:

o Always make sure the throttle (gas pedal) cable and throttle spindle linkage aren't restricting the throttle from properly closing. The throttle plate adjusting screw should be able to touch the throttle stop (LH 2.4) or throttle lever (LH 2.2).
o Release the throttle position switch (TPS) adjusting screws so that it can rotate.
o Back off the throttle plate adjusting screw so the throttle can be held fully closed with the screw not touching the throttle stop/lever.
o Holding the throttle plate lever closed, advance the adjusting screw until it just touches the throttle plate adjusting stop/lever (any further and it would start to open the throttle plate).
o Advance the adjusting screw 1/4 turn more and lock in place.

For a VDO TPS (common):
o Place a 0.25 mm feeler gauge between the throttle plate stop/lever and the throttle adjusting screw.
o Rotate the TPS slowly counter-clockwise until the click is heard then lock in place.

For a Bosch TPS (less common):
o Hold the throttle plate lever closed.
o Rotate the TPS counter-clockwise until the click is heard.
o Continue to rotate counter-clockwise until the TPS hits the end of travel (any further and it would need to open the throttle plate) then lock in place.

The proper Volvo spec for *checking* TPS adjustment is as follows:
o With a 0.15 mm feeler gauge inserted between the throttle lever and the throttle stop screw, clicks should be heard as you open and close the throttle.
o With a 0.45 mm feeler gauge inserted between the throttle lever and the throttle stop screw, no clicks should be heard when you open and close the throttle.
o Adjust to spec if this doesn't happen.

There are additional adjustment specs for the throttle spindle linkage and the throttle cable, but they are of less importance. The actual specs vary by engine type. Suffice it to say you need to maintain a bit of slack so that the throttle linkage, throttle spindle stop and the throttle cable are not limiting factors in closing the throttle.

To help maintain a smooth idle, without hesitation and stalling, make sure the throttle body is routinely kept clean. Remove the throttle body from the intake manifold for proper cleaning. The edge of the throttle plate and the area in the throat where it closes are the most critical to be clept clean, as are the vacuum orifices and air bypass channels. See the FAQ for more details.

If idle problems persist, such as an inconsistent idle or stalling, then the idle air control (IAC) valve may be dirty/worn. See the FAQ for more details.
Click to expand...
 
swedefiend said:
Google search: "Volvo 240 TPS adjustment"

First result:
Click to expand...

Thank you, but seems not fully proper from here: https://www.brickboard.com/FAQ/700-900/EngineFuelinjection.htm#ThrottleBodyandThrottlePositionSwitchAdjustment

5. Adjusting the TPS.

Loosen the TPS adjustment screws holding it to the throttle body. First turn the TPS clockwise (away from the electrical connector) until it stops. While keeping your finger on the throttle disk so it won't move, turn the TPS counter-clockwise (toward the connector) until you hear or feel a click. Continue turning until it stops, then tighten the screws. Go back to step 3 above to check the adjustment.
Click to expand...

Yours saying:
o Rotate the TPS counter-clockwise until the click is heard.
o Continue to rotate counter-clockwise until the TPS hits the end of travel (any further and it would need to open the throttle plate) then lock in place.
Click to expand...
 
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