Wayne & Irene Posted March 6, 2013 Share Posted March 6, 2013 My mechanic tells me I need a new "warm up module" because the engine stays at fast idle for too long before eventually dropping down to the normal idle speed for a warm engine. I've done lots of "googling" using this name and every variant of it I can think of, but I'm not sure I'm getting the correct name here. My mechanic tried to get a new one for me because the ribbed rubber collar on this module is cracked and letting air in, which causes the idle problem. Other than that it runs fine. I have attached a picture of the part in question. It's the thing with the white, cylindrical piece on the right in this picture. Does anybody know the correct name of this module/part so I can try to find one. Thanks for any help. Wayne Quote Link to comment Share on other sites More sharing options...
MontanaChinook Posted March 6, 2013 Share Posted March 6, 2013 Choke? I've never heard that term, either. Whatever it is, it's what controls the high idle speed, so yes, what kicks up the idle when it's cold, so your engine reaches operating speed faster, then kicks it back down once its warm. He's just calling it a made up name. Quote Link to comment Share on other sites More sharing options...
WME Posted March 6, 2013 Share Posted March 6, 2013 Well on a 22re its called an Air Valve. Quote Link to comment Share on other sites More sharing options...
Wayne & Irene Posted March 6, 2013 Author Share Posted March 6, 2013 I'm pretty sure it's called the Idle Air Control (IAC) valve but I would love to see a matching picture online. Also would like to find someplace where I can get one. My mechanic informs me that Toyota Canada doesn't carry the part anymore. :-( Wayne Quote Link to comment Share on other sites More sharing options...
zero Posted March 6, 2013 Share Posted March 6, 2013 I'm pretty sure it's called the Idle Air Control (IAC) valve but I would love to see a matching picture online. Also would like to find someplace where I can get one. My mechanic informs me that Toyota Canada doesn't carry the part anymore. :-( Wayne Toyota uses at least four different IAC systems that I know of, that are ECM controlled. What year and what engine do you have? Quote Link to comment Share on other sites More sharing options...
shim 'n bucket Posted March 6, 2013 Share Posted March 6, 2013 I have attached a picture of the part in question. It's the thing with the white, cylindrical piece on the right in this picture. Does anybody know the correct name of this module/part so I can try to find one. Thanks for any help. Wayne I'll take a stab at it. Dash pot? http://personal.utulsa.edu/~nathan-buchanan/93fsm/engine/93throttle.pdf Quote Link to comment Share on other sites More sharing options...
Wayne & Irene Posted March 6, 2013 Author Share Posted March 6, 2013 I have the 1991 V6 3vze engine in a Winnebago Warrior. I have seen a number of pictures online of Toyota IAC valves, but nothing that matches my picture closely. It seems, as well, that this part is no longer available from Toyota, at least not Toyota Canada. The actual problem with my part, according to my mechanic, is a small split in the rubber "collar" at the engine end of this module. He claims it is letting in too much air and that is causing the fast idle to stay fast for too long. I'm wondering whether a tiny drop of liquid rubber from the tubes you can buy everywhere might just patch this little split ... I can almost not see it ... and keep out any excess air but still allow the rubber collar to expand and contract with temperature changes. I'm trying to educate myself on the operation of this module and perhaps save some money. To be honest, the time at fast idle during warmup doesn't seem unreasonably long to me before it drops down to a normal idle for warm engines, so maybe this isn't much of a problem at all. Quote Link to comment Share on other sites More sharing options...
WME Posted March 6, 2013 Share Posted March 6, 2013 I have the 1991 V6 3vze engine in a Winnebago Warrior. I have seen a number of pictures online of Toyota IAC valves, but nothing that matches my picture closely. It seems, as well, that this part is no longer available from Toyota, at least not Toyota Canada. The actual problem with my part, according to my mechanic, is a small split in the rubber "collar" at the engine end of this module. He claims it is letting in too much air and that is causing the fast idle to stay fast for too long. I'm wondering whether a tiny drop of liquid rubber from the tubes you can buy everywhere might just patch this little split ... I can almost not see it ... and keep out any excess air but still allow the rubber collar to expand and contract with temperature changes. I'm trying to educate myself on the operation of this module and perhaps save some money. To be honest, the time at fast idle during warmup doesn't seem unreasonably long to me before it drops down to a normal idle for warm engines, so maybe this isn't much of a problem at all. Well its broke right, so you can't hurt it by trying the liquid rubber. Quote Link to comment Share on other sites More sharing options...
Wayne & Irene Posted March 6, 2013 Author Share Posted March 6, 2013 Shim n Bucket appears to be correct. I did find a picture of this gadget online. It is the dashpot and the rubber "collar" I was referring to is called the dashpot boot. The online picture showed this boot to be badly cut up; mine just has a very small crack in it. The expert opinion online is that the dashpot, if not adjusted right to allow the throttle to close fully, can cause the engine to stay at a higher than normal idle. The same expert opinion stated that dashpot operation should have no effect on "slightly lumpy" idle ... which I have a very slight case of... or at least my engine does. I'm not sure whether the fast idle is caused by dashpot adjustment issue or the tear in the rubber boot letting in extra air as my mechanic is stating. Any thoughts? Quote Link to comment Share on other sites More sharing options...
shim 'n bucket Posted March 6, 2013 Share Posted March 6, 2013 In the link I posted above, it details the test and adjustment procedure for the dash pot. Starts on page EG2-237. I doubt the rubber boot has anything to do with your problem. It is just covering the shaft to keep dust, etc off the shaft itself. A new dash pot is about $53 discounted, but you would have to adjust it when you installed the new one. Might as well test and recalibrate your existing dash pot first, to see if your mechanic is correct, that it is out of adjustment. Quote Link to comment Share on other sites More sharing options...
Maineah Posted March 7, 2013 Share Posted March 7, 2013 It is a dash pot it is used to slowly return the idle when you let off the gas kind of like a screen door closer it really is not necessary as far as the performance of the engine it is all about emissions. Quote Link to comment Share on other sites More sharing options...
zero Posted March 7, 2013 Share Posted March 7, 2013 I haven't studied the system for that year , but . . . the ECM must get a temp signal somewhere in order to "know" when to operate the servo for cold fast-idle. I check into the exisitence of what sort of temp sensor is used. I know that many Toyotas have a bi-metal "cold-start-sensor" but I have no idea what sensor is used for cold-fast-idle. On many vehicles, a coolant temp sensor is used. Quote Link to comment Share on other sites More sharing options...
Wayne & Irene Posted March 7, 2013 Author Share Posted March 7, 2013 I will look into the sensor issue you mention. Since the idle does return to the normal, warm value eventually, I'll also check to see if the dashpot plunger mechanism might just need a bit of cleaning, lubrication to operate smoothly. If it sticks a bit that might also explain the slow return to idle as the engine warms up. Quote Link to comment Share on other sites More sharing options...
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