Help with codes 43 and 54

[btr85vette]

I recently bought a 1985 Corvette that has been sitting for about 4 years. It had some pack rat damage to the wiring. Anyhow, I have the car running really strong, but have a problem. Originally, the SES light would come on with a 43 as soon as I started the car. I checked the Knock sensor connector, and it was damaged, so I replaced it. Now, the SES does not come on when I start the car. If I romp on it, I get like a 1 or 2 second ping from the motor, then the SES light comes on. After the first ping, it does'nt ping again until the car is shut off and restarted. Then I get a code 43 and a 54 (fuel pump low voltage.) The weird thing is that I can eliminate the 54 depending on how I move the KS connector; it seems to react to interference around the connector. After the SES comes on, I don't notice a dropoff in performance like the timing is being retarded.

Has anyone seen this scenario before? I don't want to start the slow death of randomly replacing parts.

 

[Schrade]

I don't want to start the slow death of randomly replacing parts.

:confused

I thought that was the American way - buy parts blindly and never fix the problem? The ol' Fully Automatic Assault Wallet select fire approach!

If you don't want to do it that way, GOOD!

Buy a multimeter, and the FSM - plenty FSM's on ebay. And remember, EVERY car runs great while cold (open loop). SES light on a cleared computer won't light up til closed loop (warm motor), with a few exceptions. In fact, DTC43 might be one that does if it's MAF...

 

[btr85vette]

It won't throw an SES or an error code at all unless I get on it, and it pings for a second. If I drive it "nicely" all is well, and no error code.

 

[Schrade]

It won't throw an SES or an error code at all unless I get on it, and it pings for a second. If I drive it "nicely" all is well, and no error code.

I don't think it matters.

SES 'ON', means that the DTC is current, as opposed to history. SES off means the code is STILL there, stored as a history event. Some history codes will go away ONLY after a problem is fixed, and the computer has done x number of 'reads', without picking up a reading that's out of spec parameter. Or if the computer has been cleared of the code.

Biggest misconception YUP: No light, no problem....