Problem with Idle

[90daytonaturbo]

Ok I have a 1990 daytona 2.5L turbo I (mistu) I am running into the typical fix one problem and run into the next. But this is weird to me car runs and drives good but when I floor the gas to pass another car the heater blows from the floor then when gas is applied the heater changes to defrost, thats not all when I come up to stop light and apply the clutch the car wants to idle way down till it dies this also happens when the car is parked and at normal idle I rev it up a little and when idles down it trys to die. Please can anyone tell me what is going on. Thanks

[t1turbo]

sounds like your ais motor is not returning to normal idle position when you give it gas... Instead, it is falling below normal idle position and doesn't catch itself until it See's its below normal idle.

Maybe check and reset base idle and inspect ais motor and throttle body for blockage in passages. Inspect your PCV plumbing and vacuum lines for leaks.

It sounds like boost pressure is getting into your vac line for your blower vent controller. The vac line for this runs off your power brake booster inlet. along with your cruise control. I'm guessing there should be a check valve in the line from manifold to booster?

[Sid]

The most common cause of the vents going from heat to defrost is a leaking Actuator. They work of vacuum and when you floor the car, vacuum goes down and the actuator closes. Default setting for the Actuator is "Defrost" That way if the problem happens during a severe snow storm, fogging of glass, you can keep the windshield clear. There are two actuators and they as far as I know, the same.

The problem with the Idle could be due to this since it is a vacuum leak, or as mentioned in the previous reply, the AIS, your Idle Air Control. I had problems with the AIS where idle would drop and almost die and replaced the AIS and solved the problem. So, it could be one...the other...or both. I would definitely check the Actuator first. In all my Chrysler/Dodge, they have gone bad and even in my Audi.

The original part number was 04462918
ACTUATOR, A/C Mode Door, ACTUATOR, A/C Mode Door Vacuum, ACTUATOR, A/C Mode Door Vacuum (1988), ACTUATOR, A/C. Mode Door, ACTUATOR, Heater Mode Door, ACTUATOR, Htr. Mode Door, ACTUATOR, Htr. Mode Door (1988). 1990. # 04462918, 03847849, 04462507

1983 85 87 89 90 dodge plymouth chrysler air conditioning actuator 4462918

Good Luck!

[Rustic4x4]

same kinda problem. every time i come up to a light and put the cluch in it dies.most times. just put in brand new k&n air filter , new plugs , wires , PCV valve and new belts..i was told it could be the alternator.? everything else on the car works great! minus the tach.but thats another story..please help! new alternator is 200 bucks so id like to get some ideas before i buy one....thanks!

[NAJ]

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