AMC Eagle Den Forum

The Mighty 258 => The Engine => Topic started by: max98059 on August 13, 2012, 03:32:56 PM

Title: carter bbd help
Post by: max98059 on August 13, 2012, 03:32:56 PM
so my car runs great and idles good until i put it under a heavy load and push the gas peddle down to the floor and let back up.it then stalls and wont idle until i revers 2 and 4 plug wires then it idles great. need help getting this fixed. i also welcome anyone who wants to stop by i live in lynnwood wa
Title: Re: carter bbd help
Post by: eaglebeek on August 13, 2012, 09:29:33 PM
Hmmm, that's odd. Let's start here: Firing order on the 258 6-cylinder is 1-5-3-6-2-4. The distributor rotates clockwise.
Start with where the #1 wire fits into the distributor cap and go around clockwise. The next wire should lead to the #5 plug, and so on.

You say the engine idles OK, so I don't think there's an intake leak. It couldn't hurt, however, to put a vacuum gauge on the fitting in the intake manifold. You will have to temporarily disconnect something, most likely the brake booster.
At idle it should read around 12 inches and remain steady. An unsteady or unusually low vacuum gauge indicates a bad engine valve or a vacuum leak.

These two conditions are common. When you have gone through these ideas post up with what you've found and let's go from there.
Title: Re: carter bbd help
Post by: max98059 on August 14, 2012, 01:28:28 AM
i checked the vacuum i am getting -15psi and the firing order is right it prrrs nice right after i make it back fire to clean the carb out. but i am now soaking the carb with p.i. by amsoil. carnuck and me r thinking its gonk in the bowl of the carb. but i am not a 100% sure.
Title: Re: carter bbd help
Post by: eaglebeek on August 14, 2012, 11:10:29 AM
OK...that's excellent vacuum. Tell us what happens after you soak the carburetor. :eagle:
Title: Re: carter bbd help
Post by: max98059 on August 14, 2012, 02:54:49 PM
so after 30 mins of cranking and sputtering it fired up and ran good. so far so good went on a lil drive. i think the pi strait into the carb fixed it.
Title: Re: carter bbd help
Post by: carnuck on August 16, 2012, 12:40:02 PM
That PI is great stuff. Apparently it's acting up again so I'm heded over to pop the top and fix it (crud in the idle portion of the carb usually does it)
Title: Re: carter bbd help
Post by: AMC of Houston on August 16, 2012, 05:54:00 PM
And don't forget the "drill the bottom of the idle bleed tubes out to 0.30" AMC Service Note -- usually keeps it from happening again.
Title: Re: carter bbd help
Post by: carnuck on August 20, 2012, 12:12:23 AM
.030 not .3 ;)
Title: Re: carter bbd help
Post by: AMC of Houston on August 20, 2012, 07:01:32 PM
Yep; my bad.   Chalk me up with a typo!!
Title: Re: carter bbd help
Post by: carnuck on August 20, 2012, 07:28:56 PM
Youre not the only one. I see it all over the net that way too. 1/3 of an inch (bigger than 1/4"!) is waaaay too much! Max98059 and I got the hand drill for torch tips and cleaned his out (flat spot was still there because the stepper motor needs reset and the computer is gone so we swapped carbs. )
He got the Holy Grail non-computerized rebuilt BBD I had stashed away from my '77 Pacer (only the link rod pivot was reversed)