Hello All, I've been trouble shooting a problem for a while and haven't been able to narrow it down. The car starts up fine. It has a very choppy idle because of the cam but it doesn't stall at idle. It used to stall before I came to a complete stop but the work detailed below seems to have stopped that. When I am traveling at mid rpm's (30-40 mph) I feel a shudder in the drive line. Kind of like a drag feeling. Another way to describe it is if something was sporadically tugging on the back of the car as we are going down the road. When I speed up to higher rpm's (50 and up mph) it doesn't seem to do it. Other than this issue the cars runs great. I've put on a new carb, new plugs, new coil and adjusted timing to 12 degrees. Still doing it. The tranny was rebuilt before the problem and we though it could have been a bad torque converter. Replaced that with a TCI Saturday Night Special. Could I have a sporadic misfire or could it be something in the rebuilt tranny that wasn't done right. Any one else have a similar issue? Engine is a 302 HO, Holley Street Avenger, Edelbrock RPM intake, GT 40x heads. Don't know the specs of the cam but it's way more radical than stock. Thanks!!
Which firing order? 289/302 non 302HO firing order is 15426378 instead of 13726548. The 13726548 firing order is the more modern and typically known as the 351 firing order.
I knew with the enging being an HO model that the firing order was different. I think the probelm would be a lot worse if I had the 15426378 order set-up. Do you agree?
Mine did that when I had GT40P heads and the spark plug wires were shorting to the headers. Make sure your plug wires are not arcing anywhere. Your description is very good, and sounds exactly like what mine did. I described it as feeling like I was losing 20-30 hp every now and then when cruising, and it feels like you are hitting a head wind for a few seconds. In fact, I WAS losing 20-30 hp...
I'm going to go ahead and change the plug wires and try to route them away from the headers and each other as much as possible. I'll let you know if that cures it. Thanks for the advice!!
