[mrbigglesworth]

Ok i have quite the problem. The main bearings went on my 95 V8 grand cherokee and I had to change out the motor. I bought a re-built motor from advance auto and put all the old manifolds/sensors/accesories onto the new block and head. Went to turn the key...no start. I have checked spark, timing, and fuel. All of which were o.k. The jeep will start and putt for about two seconds and then die. Also another thing I am sceptical about is the fact that the tachometer doesnt work. When the engine does run for a few seconds the tach just bounces, and I have replaced the crank shaft position sensor during the motor installation because it broke. I was thinking that the cps also runs the tach, and possibply this sensor could be bad or not working properly?? Any info would be greatly appreciated.