1989 Caravan idle at start problem
From : ron
Q: my wifes 1989 caravan 139000 miles just started to not want to idle when it is started hot. from a cold start it seems to be ok. it will start ok then die it is not holding the idle rpms. after it was run for a while it seems to be ok. is there some sensor someplace or what might be causing this thanks ron .
Replies:
From : daniel j stern
on mon 31 may 2004 ron wrote my wifes 1989 caravan 139000 miles just started to not want to idle when it is started hot. from a cold start it seems to be ok. it will start ok then die it is not holding the idle rpms. after it was run for a while it seems to be ok. is there some sensor someplace or what might be causing this you dont specify what engine you have but i bet its a 3.0 v6 which means theres probably a dirty throttle body and ais pintle causing this. -stern .
From : ron
yes it is a 3.0 v6. but it seems like everything works freely. what am i missing whats the ais pintle thanks ron daniel j. stern wrote on mon 31 may 2004 ron wrote my wifes 1989 caravan 139000 miles just started to not want to idle when it is started hot. from a cold start it seems to be ok. it will start ok then die it is not holding the idle rpms. after it was run for a while it seems to be ok. is there some sensor someplace or what might be causing this you dont specify what engine you have but i bet its a 3.0 v6 which means theres probably a dirty throttle body and ais pintle causing this. -stern .
From : ron
ok i am going to answer my last question. ais being the automatic idle speed motor. now the next question is how does this thing work does it connect to the idle cable someplace or thanks ron daniel j. stern wrote on mon 31 may 2004 ron wrote my wifes 1989 caravan 139000 miles just started to not want to idle when it is started hot. from a cold start it seems to be ok. it will start ok then die it is not holding the idle rpms. after it was run for a while it seems to be ok. is there some sensor someplace or what might be causing this you dont specify what engine you have but i bet its a 3.0 v6 which means theres probably a dirty throttle body and ais pintle causing this. -stern .
From : ron
i believe you are telling me to take the throttle body apart and clean it. no problem i am good at these things but can the ais pintle be cleaned or do i need to buy a new one thanks ron daniel j. stern wrote on mon 31 may 2004 ron wrote my wifes 1989 caravan 139000 miles just started to not want to idle when it is started hot. from a cold start it seems to be ok. it will start ok then die it is not holding the idle rpms. after it was run for a while it seems to be ok. is there some sensor someplace or what might be causing this you dont specify what engine you have but i bet its a 3.0 v6 which means theres probably a dirty throttle body and ais pintle causing this. -stern .
From : daniel j stern
on mon 31 may 2004 ron wrote i believe you are telling me to take the throttle body apart and clean it. no problem i am good at these things but can the ais pintle be cleaned or do i need to buy a new one removing and manually cleaning is much better and more effective than spray and pray so if you dont mind doing it definitely do it. the ais motor can be removed from the throttle body by removing its two or three fixing screws. carefully withdraw it from the throttle body. it is the bolt-on that is *not* directly opposite the throttle lever thats the tps throttle position sensor but youlll want to remove that too to give the t-body a good dip-and-scrub in suitably strong carburetor cleaner. my preference is berrymans b12 chemtool. -stern my wifes 1989 caravan 139000 miles just started to not want to idle when it is started hot. from a cold start it seems to be ok. it will start ok then die it is not holding the idle rpms. after it was run for a while it seems to be ok. is there some sensor someplace or what might be causing this you dont specify what engine you have but i bet its a 3.0 v6 which means theres probably a dirty throttle body and ais pintle causing this. -stern .
From : daniel j stern
of course you should also check for codes and make sure theres nothing else the matter. to check the computer codes with the engine off switch the ignition key on-off-on-off-on leaving it on. do not go to start just on during this procedure. watch the check engine or power loss light. it will turn on then go off then will begin to flash-out any trouble codes that have been stored. for instance if it flashes flash pause flash flash long pause flash flash flash pause flash flash flash flash flash long pause flash flash flash flash flash pause flash flash flash flash flash then you have a 12 one flash followed by two a 35 three and five and a 55 five and five. 55 means end of codes or if by itself no codes stored. check the codes and report what you find. -stern .
From : daniel j stern
on mon 31 may 2004 ron wrote yes it is a 3.0 v6. but it seems like everything works freely. you wont get any binding of the throttle -- the skunch builds up behind the throttle plate and in the ais pintle and passages primarily and interferes with airflow at idle. because a faster engine idle speed different ais position! is used at cold start and idle you wouldnt experience the problem then. what am i missing a spray can of air intake cleaner a torx screwdriver to remove the ais motor and a helper to start and run the engine while you spray away. whats the ais pintle ais automatic idle speed what other makers call the idle air control. it is a stepper motor which advances and retracts a pintle that travels in a passage machined into the throttle body controlling the amount of air allowed in when the throttle is closed foot off the gas -- idle conditions. -stern .
From : ron
i will give this a try and let you know what i find. thanks ron daniel j. stern wrote of course you should also check for codes and make sure theres nothing else the matter. to check the computer codes with the engine off switch the ignition key on-off-on-off-on leaving it on. do not go to start just on during this procedure. watch the check engine or power loss light. it will turn on then go off then will begin to flash-out any trouble codes that have been stored. for instance if it flashes flash pause flash flash long pause flash flash flash pause flash flash flash flash flash long pause flash flash flash flash flash pause flash flash flash flash flash then you have a 12 one flash followed by two a 35 three and five and a 55 five and five. 55 means end of codes or if by itself no codes stored. check the codes and report what you find. -stern .
From : ron
i have to assume that there were different versions of this system because this engine doesnt have a ais unit mounted on the carb. and it is listed as na on the web at autozone. ron daniel j. stern wrote on mon 31 may 2004 ron wrote yes it is a 3.0 v6. but it seems like everything works freely. you wont get any binding of the throttle -- the skunch builds up behind the throttle plate and in the ais pintle and passages primarily and interferes with airflow at idle. because a faster engine idle speed different ais position! is used at cold start and idle you wouldnt experience the problem then. what am i missing a spray can of air intake cleaner a torx screwdriver to remove the ais motor and a helper to start and run the engine while you spray away. whats the ais pintle ais automatic idle speed what other makers call the idle air control. it is a stepper motor which advances and retracts a pintle that travels in a passage machined into the throttle body controlling the amount of air allowed in when the throttle is closed foot off the gas -- idle conditions. -stern .
From : daniel j stern
on tue 1 jun 2004 ron wrote i have to assume that there were different versions of this system because this engine doesnt have a ais unit mounted on the carb. probably because it doesnt have a carb. there *is* an ais motor on the throttle body however. and it is listed as na on the web at autozone. you could not possibly find a worse source of engine configuration data than autozones parts catalogues. here from the factory service manual http//www-personal.engin.umich.edu/dastern/cars/3.0tb1.jpg http//www-personal.engin.umich.edu/dastern/cars/3.0tb2.jpg -stern .
From : ron
ok i thought i looked last night and didnt see the ais but i see it now and it is right where it should be. also correct on the carb just so used to working on carburated engines and this throttle body looks so much like a carb i just forgot myself. anyway guess i was right the carb doesnt have a ais hi ok about auto zone but we have a very good store here in phx with people that are far more knowledgeable than some of the repair shops around here that i just assumed the catalog on the web was as good. so looks like i now know what i need to do. the wife just got bad from a trip into downtown phx so the engine is kind of hot right now. i think it is around 100 outside with a high of 107 sometime this afternoon so looks like a morning project. i did ask her if the car was acting up today and she said no. up until about 4 months ago we had a chevron station at the end of the block that we gassed up at. chevron sold the station but we have still been gassing up there. i wife said her car always seemed to run better on chevron so she found a chevron station a week ago so maybe the chevron is doing the cleaning for me but after 140000 it probably could use a cleaning anyway. thanks for the help ron daniel j. stern wrote on tue 1 jun 2004 ron wrote i have to assume that there were different versions of this system because this engine doesnt have a ais unit mounted on the carb. probably because it doesnt have a carb. there *is* an ais motor on the throttle body however. and it is listed as na on the web at autozone. you could not possibly find a worse source of engine configuration data than autozones parts catalogues. here from the factory service manual http//www-personal.engin.umich.edu/dastern/cars/3.0tb1.jpg http//www-personal.engin.umich.edu/dastern/cars/3.0tb2.jpg -stern .