Newby w/question....dying 258

[magscout]

Hello Everyone,

I'm new to this forum, and no, I don't drive a Jeep. I drive an IH Scout with an AMC 258, which I just swapped in after rebuilding. The engine is new(800 miles), and has a Weber 38mm DGV 2bbl on top of a Clifford Intake. The problem I seem to have is that it is very, very cold natured. In other words, don't think about moving until the temp hits 160. I'm currently running a 180 stat. If you try to drive it before this time, it backfires, spits, and dies. Once it's warmed up, it's all fine, but it's really unlike any other engine I've been around before, previously being a V8 guy. I've played with the choke until I've run out of ideas, and it seems to have this problem no matter how I adjust it. Is it just a characteristic of these engines to be cold natured, or is there some secret I don't know yet about them? Also, does anyone here run the Howell TBI unit, or a GM setup? How do you like it, and what kind of mileage are you getting? thanks for any advice here, as I'm new to AMC engines.

Thanks,
Rhett H.
1980 IH Scout II

[sloop]

That sounds very odd. I haven't had any problems with the 258 in my '83 CJ-7 running around in 15*F weather when it snowed. Are you sure the carb is tuned? Also, I thought the Weber 32/36 was supposed to be used on 258's, the 38 is designed for a much higher CFM rate?

[magscout]

Interesting....I have actually thought at times that it's too much carb for my engine. It falls on it's butt any time you get it more than half throttle, and it's getting 12 mpg. Of course, the scout IS as heavy as a FS Jeep, but I have a header, after market intake, and MSD box. I should be getting somthing a little better even from a new engine, right? Well, I'll look into that. Thanks a lot for the reply. And yes, I've tuned the carb until I'm blue in the face.

Thanks,
Rhett H.

[Don S]

Magscout..Rhett..Is this a full size 258? The only I-6 I have is a AMC 232 and it is a honey. My 401 got cold natured like yours when the heat riser baffle below the exhast man. was removed. This helps the carb & choke to work. I installed a hand choke to help with the problem but it sounds like you may not have a carb...sounds like its to lean for the cold. look out the back, if you see black smoke its to rich..... smile.gif ...ds

[magscout]

Don,

Yes, it is a full sized 258 from a 1973 Scout II. The heat riser deal sounds reasonable, as I don't have one, due to the fact that I have a header. Also, the carb has a pain in the butt electric choke. The problem with the idea that it's not liking the cold, though, is that I live in Houston, TX. It shouldn't be a problem at all. I guess the carb could be a lemon, though? Well, when I get tired of hearing it backfire when not blazing hot, I'll go GM TBI! Thanks for the input.

Rhett H.
IH Scout II

[Don S]

Mag Scout..An 84 CJ friend jerked the stock carb then a high $ web and then installed the GM V-6 system. We went to y-o jamboree and it ran pretty good UNTILL a Blue Norther hit. Many mucho dinaro later he gave up and custom factory ordered a TJ. He's happy now...isn't it nice to be RICH.. :eek: :eek: ... :rolleyes: .....ds