I have a an older MGT 4.6 that I picked up used recently and recently took the engine out, gave it a clean and sealed the backplate as is was not running reliably. Well...I finally got some time today to play with the 4.6 after reinstalling it. I am having some odd results. I took the HS and LS needles to the factory settings and it started on the first pull no problem. I adjusted the idle and just let it run for a bit with no throttle. Maybe 1/4 tank no issues. So I then took it out in the alley and began to tune it. I first started with the high speed needle and got it set just right. Then I adjusted the low speed. Runs pretty good, but it can be leaned a little more I think. For now I will leave it be until I hear back from this post. Funny thing is it runs great for about 1/3 of a tank and then stalls. It is not possible to start it again until it cools down which is weird as it is only 185 degrees at the glow plug after hard driving for a few minutes? Not hot by any means.

I can only assume that as the engine heats up it is developing air leaks. But would this not lead to it getting MUCH hotter than 185? I am a little confused. I am willing to admit the engine needs to be replaced, but I want to be sure this is a good learning experience. No point putting in a new engine every time the one I currently have some issues.

BTW I noticed that after hard full throttle run, the idle has a purr like sound (kinder sputters very rapidly) for a minute or two then returns to a smooth sound. Watching some Youtube Savage tuning videos this same sound happened when it was too lean (follow this link then go to 3 mins 30 seconds to hear the sound I am talking about), though in my case I am pretty sure I am not anywhere near lean. Lots of smoke and good temps.

Thanks as always everyone,
matt