Running rich

[homeselljeff]

My car runs fine for about 10 minutes and once it's warm when driving it looses power and blows black smoke like it's getting too much fuel . Could it be the Frequency Valve?
And how would I check it?
Thanks


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[David T]

My car runs fine for about 10 minutes and once it's warm when driving it looses power and blows black smoke like it's getting too much fuel . Could it be the Frequency Valve?
And how would I check it?
Thanks


Sent from my iPhone using Tapatalk

Probably not the frequency valve. Either the mixture screw is way too rich and/or you have 1 or more bad injectors. The running rich isn't as bad when the motor is cold but when it warms up it is too much. The mixture screw is often screwed too rich to try to compensate for the frequency valve not operating.

[sdg3205]

You can hear the FV. It sounds like a fast paced buzz/click. If you're not sure if it is working, you can unplug it from the bulkhead and see if your idle changes or car stalls.

When I bought my car the lambda system didn't work because a terminal in the lambda relay socket was backed out. The mixture was set rich to compensate and it destroyed the cat.