I got my new engine running yesterday but it runs like crap. First start up it ran like crap and then after we checked all the wires and started it again it ran smooth but at like 500 rpms. Well then a few minutes later it was running like **** again. It idles about 600 rpms and lopes REALLY bad. The motor shakes and you can almost time it when its gonna hit really bad. Like it will shake and then shake really hard like a thump and then stop and do it again about a second later. It pops really bad once it gets up to about 2500rpms. If anyone can give some suggestions it would be great. Everything in my signature is brand new and was put on with the new motor. Thanks.

 

TTT.....i really need some input on this!!

 

If the motor is popping, then that means you have some plug wires messed up. ABout the only way a motor is gonna pop is if the firing order is off. A friends stock motored car loped really hard and popped when a few plug wires were off. Double and triple check your wires first. Maybe swap on a different coil to try.

 

what tune do you have in it? sounds like it may be in the tune. also, how do the plugs look? new right? sure they are not getting fuel fouled? no burned plug wires right? (I know all this stuff it prolly new)double check them. sure the valves are adj. properly? cant hurt to run through them one more time now that it runs and the lifters are full of oil. it shouldnt pop at all. any exh. leaks? also check all the eng. grounds.

 

could be as simple as a vacuum leak...

 

Sounds dumb but, make sure your INTAKE boot is on the TB perfectly. The smallest leak on the intake boot at the TB (or after the MAF) will cause a HUGE problem in the way an engine runs. Usually the underside will be on wrong , even if the top looks like it is on right. make sure it slides on and off easily, otherwise, it is on wrong. It should slip right on when on there right.