97 GMC Safari w/ 4.3(W) V6 vortec. 195k miles. Engine is running very rich. 10mpg. Smell of gas sometimes coming from exhaust when running. It has rough idle, and dies, especially when cold. Lacks power, but sometimes briefly works fine. Not throwing any codes. I have replaced and/or checked for proper operation; plugs, wires, coil, distributor assy. (incl CMP), O2 sensors, CAT pipe, fuel filter, Fuel pump assy., EGR, MAF, MAP, TPS, IAC, PVC, fuel pressure regulator and air filter. The timing chain was also replaces and checked four times to make sure EVERYTHING was in sync. Fuel pressure is within parameters and the vacuum is solid, as well. Inside the plenum it is coated with a layer of black, gritty soot. No fuel puddling though. This has been plaguing me for two months now. Big thanks in advance.

Thought the same thing, but also thought it might be a good idea to check all of the accessible new parts installed first, because new doesn't always mean good. The new MAP turned out to be bad. Voltage was in parameters but well below where it was supposed to be. Some of the other parts actually did need replacing when I did, but since it was a multi-step problem, finding the real solution became a bit more difficult. Give me a carb any day!!! Now I have a few "new" parts to sell... Thought the same thing, but also thought it might be a good idea to check all of the accessible new parts installed first, because new doesn't always mean good. The new MAP turned out to be bad. Voltage was in parameters but well below where it was supposed to be. Some of the other parts actually did need replacing when I did, but since it was a multi-step problem, finding the real solution became a bit more difficult. Give me a carb any day!!! Now I have a few "new" parts to sell...