What are symptoms for bad canister valves?

 

A few
Rough idle. One of the first symptoms that a faulty canister purge valve may produce is a rough idle. ...
Difficulty starting. Another symptom commonly associated with a bad canister purge solenoid is difficult starting. ...
Check Engine Light comes on. A defective canister purge solenoid may also set off the Check Engine Light.

 

A very good list indeed , and about all I can think to add would be the occasional whiff of raw fuel under the hood as the unpurged can becomes full ...

 

No codes for ccp solenoid, this is the tank vent. A gas smell for a stuck open solenoid. Stuck closed will as mentioned may cause running issues. Ifaik the ccp is not active at idle just during cruise. The purpose to vent the gas tank fumes.
A plugged canister might leak raw fuel. Replacement filters are available.you asked on another thread about bad injectors what symptoms do you have? Stock multec injectors still installed ?

 

Thanks for the replies and the PIX. I inherited the injectors, so I don't know what I've got.

I'm getting Code 46, "low voltage to the fuel pump." The fuel pump was upgraded when the engine swap was done. Car was okay then, though it seemed to be running rich and plugs fouled quickly; but mileage was at EPA average.

Car stalls at lights intermittently. Trouble light comes on intermittently. When it comes on at cold start, restarting after 10 seconds makes it go away. When the trouble light is on, car is sluggish & needs more gas; shifting is jerky. There doesn't seem to be pressure in the gas tank, when cap is removed.

An Auto Electrician installed performance harness and fixed bad splices and grounds, so I don't think I've got a bad ground, but you never know.

 

Code 54 maybe 46 is for vats. It could. It could the ecm or at the ops.
The ops is the splice for ecm feedback .possiable causes for low pump voltage detection bad pump ground, fp relay, ops or bad ecm. The ecm monitors the voltage on the fuel pump circuit. If it sees a voltage of less than 2V for about 2 seconds, this code will be set. This can also be set by a faulty charging system, but the most likely cause is either a loose or corroded connection in the fuel pump circuit.Not sure what year your working that will determine what pin to test at the ecm. Sounds like your running in limp home mode. If this is the 89 in your profile it's pin b2 90-92 v6 should be e13 running to verify the pump voltage the ecm is seeing.

 

Good call. It was the ECM.

 

Glad you got it solved.