i’m trying to find if anyone out there can help me i am so frustrated 😡 my 57 F600 with a freshly rebuilt 272 with brand new hei distributor/coil new plugs wires freshly rebuilt original 2300 holley carb it idles great fires right up then after about 2-3 minutes a small pop is heard from the exhaust like a faint “dud dud dud” one right after the other with about a 3 second pause. and my vacuum gauge drops one mark (21”) when it’s popping then goes back to normal (22). i retard the timing it pops louder if i give it a little throttle it goes away. around 1,100 rpm it has done this for a while now. but now this time when it’s totally warmed up it will just randomly die and nothing brings it back while it’s dying out. but it immediately fires back up when im driving it it’s fine but when it’s at temp and idles for a little bit it will die. i reran every ground on it with new wire and soldered connections thinking maybe that was the culprit. does it sound electrical? if it does what would i test?? Thanks, john

Without more information, this sounds like a coil breaking down.  If you have an electric choke, then this issue could be coming about as the choke opens and the mixture leans.  Have you tried running the engine with the vacuum advance unhooked to see if that is where the 'popping' is coming from?

Lorena, Texas (South of Waco)

This post is a continuation of a previous drive-ability concern -

http://forums.y-blocksforever.com/Topic140897.aspx

You said previously a buddy gave you a GM style HEI DIST. Was this happening before the DIST change?

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hi guys yes it was making the popping noise before it never died before though, with the original stock distributor that was on it i tried 3 different new coils different brands of points and condensers and that still never solved it, the old distributor wouldn’t hold timing and, and it had 215,000 on the distributor that’s why i got a new one it was a NIB hei kit he just never used it he got rid of his y block before he put it on so it is new parts but now its dying after a certain amount of time. but only when it idles for a little bit it will drive just fine but if i stop and idle for a couple minutes it will die then fire right back up. also the coil is separate from the distributor cap if that helps. (and sorry for the 5posts of this yesterday i didn’t mean to my internet was so slow and i hit the button 5 times, and i also didn’t think the last post i put this on was live it said it wasn’t i didn’t mean to over post this lol)

also would posting a video of what it’s doing help out?

jbrake57 Posted -

...it was making the popping noise before it never died before though, with the original stock distributor that was on it i tried 3 different new coils different brands of points and condensers and that still never solved it, the old distributor wouldn’t hold timing and, and it had 215,000 on the distributor that’s why i got a new one

it was a NIB hei kit he just never used it he got rid of his y block before he put it on so it is new parts but now its dying after a certain amount of time. but only when it idles for a little bit it will drive just fine but if i stop and idle for a couple minutes it will die then fire right back up. also the coil is separate from the distributor cap if that helps."

HEI implies to me GM HIGH ENERGY IGNITION. Did you replace the points/condenser with a module or a complete distributor? You replaced the OEM DIST (HT mechanical) with a PASS CAR rebuilt?

Does NIB refer to NEW IN BOX or a brand name? Do you know the manufacturer?

When you replaced coil(s), did you test ballast resistor and IGN SW?

Is this truck a work truck or driver? When the engine was redone, was it to HD specs or LT specs?

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i replaced the whole distributor it was new in box, i believe it was from CRT performance. the rebuilt specs on the engine i’m not sure about the previous owner rebuilt it. the most rpm i can get out of it is about 2900-3000 so my guess is it’s the MD or HD version? i’m not real sure i know nothing about y blocks (or really any engine i get the basics) this is my first one i’ve actually done work on. i did not test the coil nor ignition switch, it required i bypass the ballast resistor in the instructions that came with it. it’s pretty much a driver it will haul dirt and rock every now and again but not too often it’s mostly just going to be driven for fun 12-15,000 miles a year or less. but how do i go about testing the coil or ign switch? also the coil is mounted on a heat sync bracket it’s not the cylinder kind it’s a flat one. does the direction it’s mounted matter? (the coil)
thanks, john

CRT is one of the Chinese MSD copies.  A true GM HEI style version is far to large to fit in the space available in a Y.  I've been involved in an attempt to do that.

One thing about previous owner rebuilds - if you didn't get documentation then it should be assumed that it wasn't rebuilt.  Further, the definition for rebuilt varies greatly depending on who you ask.  For some, it may only be new rings, bearings and gaskets without really checking anything to be considered rebuilt.  For me, it's checking everything, knowing every dimension and addressing any issues found so that the final product is like new or better.  This is another reason that documentation is very important, so that you know what they call "rebuilt."

As far as coil mounting, does it have a brand name on it?  Best to get instructions from the manufacturer to eliminate guessing.

The ignition switch is easy to rule out.  All you have to do is run a temporary jumper wire directly from the battery to the appropriate terminal or wire to power the ignition.  Here again, you need the instructions for the particular ignition components you are using so that you don't fry anything.  With this jumper wire in place, does the problem still exist?  If yes, then it is not the ignition switch.  If no, then it could be the ignition switch or a bad connection somewhere in the circuit.


Lawrenceville, GA

It's a HEI SMALL CAP VERSION (GM used this style also). It has an remote E-COIL rather than a remote canister coil. Most electronic canister coils are not oil filled so no worry about MTG position. The E-COIL can also be mounted in any position.

Try bypassing the IGN SW as described. It also may me be that the DIST/COIL is drawing more AMP than the OEM switch was designed to handle. You might want to consider powering the system off a dedicated BAT connection with relay/fuse.

As for engine RPM, it is definitely a HD as all is designed for LOW RPM-HI-TORQUE. You will have to make some changes to get anything different in performance.

CRT DIST - https://www.ebay.com/itm/FORD-Y-BLOCK-239-256-272-292-312-HEI-DISTRIBUTOR-BLACK-45-000v-CANISTER-COIL-/352465223465

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Don't know if it might be part of the problem,  but those distributors were notorious for the wires cracking inside the distributor.  All it took was the vacuum advance to turn the plate in the right way and boom,  engine quits.  I've seen a car  years ago that acted the same way.    Owner replaced the pickup inside the distributor, and it fixed the problem.  Although it does sound like a bad coil.