Here's my problem...
'94 Suburban K2500, 454/AT, Loaded...
Truck has a zillion miles on it, and runs good with the exception of an annoying "BOG" when I jump on it...
What I've noticed is, with a timing light attached, the timing will advance properly when I slowly bring up the RPM's but when I crack the throttle wide open or real quickly, the timing stays retarded and the motor bogs REAL bad...
I've replaced the fuel filter, which made a BIG difference, the TPSensor, and the IAC Valve...
All of which helped, but it's still not "right"...
My guess is, it's either a p/u coil/timing related problem, or a fuel pump taking a crap...
The fuel filter I took out was almost completely clogged...I tried blowing through it, with no success...
If I had to take a guess, it almost seems like it's starving for fuel...regardless of the lazy timing issue...
I was thinking of putting in an older mechanical advance distributor, and eliminating the computer controlled unit...
Any ideas guys ???