I have a 1991 blazer that died on the freeway like it was running out of gas. In the oast when this happened I just replaced the fuel filter and was on my way. This time it is something else. I can crank it but as soon as I try to accelerate it dies. I replaced the TBI carb, & IAC sensor and that did not help. I've noticed a pretty hot exhaust, no vacuum on the carb ports and manifold port. Could this be related to back pressure issues or a tune up? What should the spark plug wires ohm at?