I've been working on my '89 v12, lots of parts, time, and head scratching. Our local guru here in the Denver area now thinks it may be running rich. It's like the fuel system can't see the engine demands when revving or sustained high speeds. Runs for about two minutes then shuts down. Where do I start. I have a CD, book, Kirby Palms work. Is there a newer CD with 5.3 & 6.0 together that may show me something I'm missing.
Submitted by dougdwyer1@com… on Mon, 05/26/2014 - 10:59
How rich is 'rich'? A minor rich condition wouldn't cause the engine the die after two minutes. In fact the engine might like it! A gross rich condition, though, could cause the engine to die.
A skewed coolant temp sensor (or dirty connection inside the connector) could cause rich mixture.
A 'full load' switch stuck closed could do it, too.
A leaking fuel pressure regulator is possible, or a fuel pressure regulator that isn't leaking but simply isn't regulating pressure properly.
A fuel injector harness shorting-to-ground is possible. This allows the injectors to stay 'on'.
A disconnected or broken vacuum hose to the ECU in the trunk is something to look for.
Cheers
DD