pmd controls ?????????

[pirate]

what does the pmd control? idle? amount of fuel mixture? timing? cold starting? how do you know when they fail? is there away to make my 97 gmc run with out it? does a performance chip replace it? if so whats a good one ? thanks

[DmaxMaverick]

The PMD doesn't control anything. It is only a signal amplifier. A driver (the D, in PMD or FSD). It amplifies the injection pulse signals from the PCM, which are too weak to fire the fuel control solenoid at the high frequency required. Timing, cold starting and idle speed are controlled by the PCM.

No, you can't run without it, or something else that does the same thing (Sol-D or D-Tech). When they fail, the engine doesn't run. They work until they don't. Usually, they are intermittent before complete failure (unexplained stalling). A performance chip only changes the PCM signals sent to the pump, which controls fuel volume and timing. The PMD function remains the same, regardless of the programming.

[pirate]

thanks for the quick reply