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98 Plymouth Breeze, 2.0 MFI rough idle when A/C on, Help!

4132 Views 0 Replies 1 Participant Last post by  drarchibald
I'm at my wits end!

My 1998 Plymouth Breeze, which has the 2.0 MFI engine idles rough whenever the A/C is turned on. Here is the testing I have done so far, along with the parts I've changed:

Originally, I thought the issue was with the A/C compressor itself, since about a year ago I was havin problems with it, and installed a compressor obtained from the scrap yard. The compressor was making "grinding" noises when engaged. This time, I purchased a re-manufactured compressor from a parts dealer. I installed it and had my local garage re-charge the compressor for me, since they also dis-charged it. But the problem has persisted.

When I researched this topic, "rough idle when A/C on" I found references to the IAC, the Idle Air Control Valve. I did the testing recommended in my Haynes manual, which consisted of attaching a vacuum tester, and then checking the IAC itself by observing the pintel retracting by plugging it in after removal from the TB. Mine did not retract at all, so I replaced it.

No resolution. I then replaced the PCV valve and again, I still have no resolution.

There are no codes present whatsoever, so I don't want to just keep throwing $$ at this problem. I have since done the Vacujm test again, and these are the results:

When you first start the vehicle, the tester reads at about 17 in Hg vacuum;
When you put the vehicle in drive, the tester reads at about 15 in Hg vacuum;
Finally, when you engage the A/C, it fluctuates and then settles at about 10 in Hg vacuum;

Again, there are no codes present in the system. Any help is greatly appreciated. Thanks!