A/C causes hesitation

[johnnybronco]

Whenever I switch on the A/C my '90 B2 starts running rough- pretty much has less power going uphill and it lurches sporadically, every few seconds- uphill, downhill or level. Thing is, my mileage is not being affected, just the performance. Any ideas as to what could be causing this?

 

[adsm08]

Compressor might be going out. Might just be time for a tuneup.

 

[johnnybronco]

It's pretty much always done this even after new plugs, wires and distributor cap in the past, although it is getting worse lately. Could it have anything to do with the timing?

 

[adsm08]

Timing could be out, but you should see symptoms at other times of high load as well.

How well does the AC work?

 

[shane96ranger]

Does it only do it the A/C on, or does it do it under a load as well (i.e. towing a trailer/hauling something)?

 

[johnnybronco]

AC is good. I don't have a lot of power going up mountains with a couple of hundred pounds in the back, but I don't know if that is normal for the B2.

 

[adsm08]

Couple hundred pound as in two full grown adults and some tents and food in the back seat, or couple hundred pounds as in a trailer with two four wheelers in it?

 

[johnnybronco]

2 adults, tent, guitar, amp, coolers, bags of clothes, tools etc...

 

[adsm08]

Well, it should be able to handle that without noticing. My 87 pulled what had to be a few thousand pounds in a trailer (including the trailer). It wasn't fun, but once I got it rolling and into 2nd gear you couldn't tell the weight was there. Just had to stay out of OD, and obviously no street racing.

 

[johnnybronco]

I also notice that the engine rpm goes up and down as the compressor clutch is going on and off while I'm idling. Don't know if that is normal or not?

 

[adsm08]

Watch the belt with the A/C on. See if it seems to jerk around when the compressor is on. It may be binding internally.