So I got my rebuilt motor started for the first time today. It idles great and sounds to be running smoothly. So far I've let it run for three hours straight, I went to run it easy around the block. In second and third gear it seems to be cutting out, almost as if the fuel was being cut off for a split second. What could be the problem? Also when it had the old motor in it was overheating. I found it was a bad coolant seal. Now with the new motor, during idle the temp is in the high end of the normal range, but when I go to drive it it starts to overheat right away. What's the deal here. I'm gonna take the radiator in on Monday and have it cleaned and checked out. The radiator is stock and it might be going bad. Any ideas would be awsome. Thanks. -Steve

 

Kevin, I know you're on here, talk to me

 

Kewl...lotsa smoke at startup huh? :-) FWIW, the idle is never perfect or even great for the first few hundred miles...nor is the power, response, or fuel economy.

Perhaps a bad main engine ground or the like. Maybe you have some bad gas or something, like the car I just started today (87 w/rebuild). Perhaps you should consider changin your plugs, rebuilds will foul plugs like hell, since they run so unevenly and so rich, especially in cold weather...it could be a LOT of things man. THis is the point where someone with experience pretty much needs to be there, in front of it, behind the wheel, putting their hands in it.

Better take that thermostat out asap. You can run w/o it until you figure out the problem. I cannot stress the importance that the engine must not get hot. Stuck thermostats on rebuilds are a common thing; the engine the housing came off of likely sat a while, as opposed to daily driving. The engine yours came off of sat about 1 month, so it could be very well a bad thermostat. Also, could be a bad fan, theyll cause symptoms like that. Are all your plastic cooling panels in place (2 in front, 1 under radiator)?

 

I put a new thermostat in and took out the stock fan and put in a 16 inch fan.

 

Sorry Kevin, I know you're busy, I wasn't trying to push you, I was simply trying to get your attention. -Steve

 

It's alright man, I wasnt mad, just...you seemed maybe freaked out or something.

 

Right on, man, I tell you, it wouldn't start for the longest time, then I switched the fuel lines and it fired right up. I'll take out that thermostat until I figure out the problem. -Steve

 

Have you checked your battery terminals??..they might be loose. This happened to my friend's NA. After dropping in his motor he drives around and motor just dies after 3K. Turned out that his battery terminals were loose.