Throttle and defrost

[Chris67]

Hope I am posting this in the correct place.
Any one have problems with acceleration when the defrost is on...like a lag? I have this every time I stop only with the defrost on. More annoying than anything but would really would like to know why this happens. Would a vacuum issue cause acceleration issues when the defrost is on? I just replaced the belt and tensioner. It was happening before that. Hope someone can help out. Thanks.

Chris

 

[xplorercrazy]

Does it happen with the A/C on as well?

 

[Chris67]

Does it happen with the A/C on as well?

havent tried that yet

 

[imp]

Hope I am posting this in the correct place.
Any one have problems with acceleration when the defrost is on...like a lag? I have this every time I stop only with the defrost on. More annoying than anything but would really would like to know why this happens. Would a vacuum issue cause acceleration issues when the defrost is on? I just replaced the belt and tensioner. It was happening before that. Hope someone can help out. Thanks.

Chris

My guess would be that "defrost" requires switching in some moving component, like a door, moved by vacuum operation. If a big vacuum leak exists downstream of the "switch" which diverts vacuum to that door, it would allow un-fueled air to be sucked into the engine, confusing the PCM trying to maintain proper air/fuel ratio. imp

 

[Limited02]

How bad is the lag? When I turn on my defroster, the engine does bog very slightly but lag isn't there.

If I remember correctly, when the defroster is turned on, I think the A/C pump turns on? I used to unplug the A/C pump on my Ranger in the winter because of that.

 

[Chris67]

I added a couple pounds of freon today. Seems to work fro now...going to have a HVAC buddy check it tommorrow