Idle rough, stalls using AC

zenon

Member
car dies when AC compressor kicks on. does not happen with AC off.

1998 protege, 1.5 L. recently dealer flush of injectors, decarbonized, replaced plugs, plugwires and air filter. replaced AC cooling fan.

Instead of dying, the idle will fall to almost a stall (250-300 RPM) and recover by jumping to over 1100 RPM.

I can reproduce the problem by imitating rush hour traffic. slowly raise the RPMs to 1600, pause then let it advance beyond 2000. release accellerator and the car will appear to settle to idle. when the AC kicks in, the pattern will reappear.

Also, if you race the motor to 1600 then try to advance it slightly more, the engine will leap to 2300 or more with almost no pressure on the gas. It's like there is a flat spot somewhere in the signal.

thanks for replies.

z.
 
I also have a 98 pro DX 1.5L and with auto. I notice a big loss in power with my a/c on but never a stall.

I'm curious to know what you find out.

You might also want to post or search for this on clubprotege.com
 
Problem Fix!

Thanks for reference to the other site clubprotege.com. After reviewing a bunch of comments there and a few elsewhere I concluded that my Throttle Position Sensor (TPS) was failing. Since other sensors had failed (I have 107,000 miles) I decided to replace the TPS. I bought one from part shop and it is now working very well. It even passed the rush hour traffic test and the reproduction tests.

Very good performance and the replacement even fixed a flat spot in my acceleration.

z.
 
zenon said:
Thanks for reference to the other site clubprotege.com. After reviewing a bunch of comments there and a few elsewhere I concluded that my Throttle Position Sensor (TPS) was failing. Since other sensors had failed (I have 107,000 miles) I decided to replace the TPS. I bought one from part shop and it is now working very well. It even passed the rush hour traffic test and the reproduction tests.

Very good performance and the replacement even fixed a flat spot in my acceleration.

z.

Glad you got things fixed.

Did your check engine light come on at all? My check engine light came on and some of the symptons you described happened to me, but not as extreme. I don't have an RPM guage so I have no idea what's going on. (why they didn't install one with this model ... I have no idea. This is how i feel about that (nuts) )

How is the throttle position sensor related to the A/C?
 
Not sure how TPC relates to AC. The Engine light only came on after the stupid dealership flushed the fuel injectors and de-carbonized the intakes. Then it went out when they replaced the plug wires, the AC cooling fan and the plugs. That also cleared the engine miss but not the AC stalling.

z.
 
zenon said:
I concluded that my Throttle Position Sensor (TPS) was failing. Since other sensors had failed (I have 107,000 miles) I decided to replace the TPS. I bought one from part shop and it is now working very well. It even passed the rush hour traffic test and the reproduction tests.

Very good performance and the replacement even fixed a flat spot in my acceleration.

z.
How much was the TPS?
I may need to get one as my car was dying out as well.
My brother adjusted the idol adjustment screw and it works fine, but at times (A/C on or not), the car starts to drop down to about 500 RPM's and the car starts to shake. It won't stall now that my brother adjusted the screw.
I want the car to run smoothly. My brother is going to mess with the distributor and by adjusting the valves and such.
My brother said that this is the first car where you can adjust so many different things. He is very impressed.
Any help is much appreciated.
 
it cost.....

Homer Simpson said:
How much was the TPS?
I may need to get one as my car was dying out as well.
My brother adjusted the idol adjustment screw and it works fine, but at times (A/C on or not), the car starts to drop down to about 500 RPM's and the car starts to shake. It won't stall now that my brother adjusted the screw.
I want the car to run smoothly. My brother is going to mess with the distributor and by adjusting the valves and such.
My brother said that this is the first car where you can adjust so many different things. He is very impressed.
Any help is much appreciated.

It cost about $125.00. I avoided adjusting the idle screw since that can apparently cause the computer to miscalculate the other elements from what I read.

I would also avoid dinking with the distributor; these cars have multiple sensors and they are so balanced, any change in one elements seems to destablize everything else. However, I'm no mechanic. and it's your car so good luck!

z.
 
zenon said:
It cost about $125.00. I avoided adjusting the idle screw since that can apparently cause the computer to miscalculate the other elements from what I read.

I would also avoid dinking with the distributor; these cars have multiple sensors and they are so balanced, any change in one elements seems to destablize everything else. However, I'm no mechanic. and it's your car so good luck!

z.
Thanks for the advice.
 

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