Reatta Fan Posted January 30, 2004 Share Posted January 30, 2004 I've been having a strange idle issue with my '91 Reatta (901445). How to make the condition happen and the symptoms are as follows: Start it up, drive a bit, stop, put the car in park or neutral. Sometimes, the engine RPM does not return down back to idle speed (~600 RPM). Instead, it will stick at a value between 1500 - 2000 RPM. I noticed this was happening as the engine RPM was unusually high in city driving and would not decrease when coming to a stop making it more difficult to stop. As far as I can tell, distance and outside ambient temperature aren't factors.When this happens, I've tried quickly depressing the accellerator but no luck in slowing the RPM down however, if I turn the car off and restart it, RPM's will be normal and stay that way until at least it is turned off again.I have downloaded the 91 service manual. I've also driven w/ the car in diagnostics. No trouble codes are present. ED01 (Throttle Position Sensor) reads .46 when stopped and no accellerator is applied at both the expected 600 RPM and faster 1500-2000 RPM. ED07 (O2 Sensor) varies between .4 and .85 and does change rapidly as the manual indicates for a good sensor). I've checked for accellerator cable binding also and nothing.Has anyone else experienced this or can anyone shed some light on something else to try to pinpoint the trouble? Link to comment Share on other sites More sharing options...
Guest HessLakeGuy Posted January 30, 2004 Share Posted January 30, 2004 Try this:Remove air tube from the throttle body. There is a snap ring. remove that. There is then an air foil-use two picks to jimmy it out. Then you see the throttle body butterfly-that needs to be cleaned. Try spraying with a high quality Throttle body cleaner, such as 3M. Wipe clean, test throttle body to makesure it does not bind, then reassemble.Might start hard the first time.This might solve it. This is a common problem with some Cadillacs. Link to comment Share on other sites More sharing options...
Guest Greg Ross Posted January 30, 2004 Share Posted January 30, 2004 Cleaning of the Throttle Body may help if the Butterfly is corroded and not closing properly. If you're going to follow that advice then remove the MAF first, rather expensive and very easily damaged!More likely it's the IAC. This little valve is operated by the ECM to control the idle level. If crudded up it will stick open as you describe. It's located on the front of the throttle body and tipped downhill slightly, and on the '91 (3800 series I) is rather difficult to remove. The two screw heads are difficult as there's no headroom for a screw driver. Once removed you'll find what's called the pintle, it's like a little plunger that runs in and out in a recess in the TB to regulate Idle Air. Use carb cleaner or the equiv. on both the pintle and the bore that it goes into.Nic pointed out before that these screws are stainless steel so when you do drop one it's next to impossible to retrieve.%#?*!!$*+?> or words to that effect! Link to comment Share on other sites More sharing options...
Reatta Fan Posted January 30, 2004 Author Share Posted January 30, 2004 HessLakeGuy & Greg & Nic,Thanks for the advice. I'll go exploring in the throttle body and IAC areas this weekend. One question remains though: If the butterfly or the IAC valve was sticking, why does a power off, power on reset (restarting the car) clear up the condition? Link to comment Share on other sites More sharing options...
Guest Posted January 30, 2004 Share Posted January 30, 2004 Your problem is the IAC. It is dirty and or sticking. When your restart the engine the computer cycles the IAC. This is a very common problem and easily corrected by spray cleaning the valve with a throttle body cleaner and lubricant which is available at most auto parts stores. Link to comment Share on other sites More sharing options...
padgett Posted January 30, 2004 Share Posted January 30, 2004 I always put a rag under the IAC to catch the bitty screw I always drop. Link to comment Share on other sites More sharing options...
Guest imported_daddy3jr8 Posted January 30, 2004 Share Posted January 30, 2004 Padgett, What's your address? I'm gonna come live with you for about a year and learn all these little tricks you have for anything being done! Not only that, it's 8* with -16* wind chill here now. Reatta is getting CABIN FEVER!!!!!!! Really do app. your knowledge and time it takes to reply,Wayne-in the freezer I DON'T SEE HOW THEY CAN STAND IT ANY FARTHER NORTH! Link to comment Share on other sites More sharing options...
Guest EDBS0 Posted January 31, 2004 Share Posted January 31, 2004 You don't mention how frequently you drive your car. The reason I ask is that I have found if the car has sat a long time or you have an unusually high battery drain the computer will sense that and keep the idel up in an attempt to recharge the battery. Your battery could be weak and not keeping a charge. Just my 2 cts (worth 22% more these days). Link to comment Share on other sites More sharing options...
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