Exploding muffler

[Columbanus]

Hello all,

I've had my 620 for about five years now. Something about the look and proportion of the truck has struck my fancy since childhood (some machines just look right) so I bought one and have been relatively trouble free - until today. Accelerating from a coasted stop the engine all of a sudden got raunchy: POP! slug-slug-slug POW! putta-putta-putta KA-BOOM! I limped into Lowe's (just after some 2x4s and Kilz, truck full of demo debris) and found the muffler had literally popped open! Once breathing freely and unmuffled the engine continued to run horribly and loudly. I did all sorts off trickwork with throttle/clutch/gear combinations as my little truck, before a reliable little angel, turned into something worse than a highschool beater.

Previous experience with a Toyota and a very undue level of confidence led me to think changing the plugs would do it ($10 today and f*** the muffler 'til later). ~150 feet later we were done. Stick-a-fork-in-it done.

Just spent way too much money (according to friends) on a successful frontend rebuild ('78 discs on a recovering lowrider) and have crossed the rational line.

Is this a distributor problem or am I in for something bigger? It's not exhaust: all potatoes were belched out with fury. No awful sound from under the hood, yet.

 

Thanks for any responses,

Glad to have found the site,

Columbanus

[Braden]

Hello all,

I've had my 620 for about five years now. Something about the look and proportion of the truck has struck my fancy since childhood (some machines just look right) so I bought one and have been relatively trouble free - until today. Accelerating from a coasted stop the engine all of a sudden got raunchy: POP! slug-slug-slug POW! putta-putta-putta KA-BOOM! I limped into Lowe's (just after some 2x4s and Kilz, truck full of demo debris) and found the muffler had literally popped open! Once breathing freely and unmuffled the engine continued to run horribly and loudly. I did all sorts off trickwork with throttle/clutch/gear combinations as my little truck, before a reliable little angel, turned into something worse than a highschool beater.

Previous experience with a Toyota and a very undue level of confidence led me to think changing the plugs would do it ($10 today and f*** the muffler 'til later). ~150 feet later we were done. Stick-a-fork-in-it done.

Just spent way too much money (according to friends) on a successful frontend rebuild ('78 discs on a recovering lowrider) and have crossed the rational line.

Is this a distributor problem or am I in for something bigger? It's not exhaust: all potatoes were belched out with fury. No awful sound from under the hood, yet.

 

Thanks for any responses,

Glad to have found the site,

Columbanus

hmmm, check the points and report back

[benzo]

had this same thing happen to me on my 240Z it blew the muffler off the pipe. ended up my coil wire came loose and cause a backfire. check the ignition items.

[Skib]

welcome to Ratsun :D

[danfiveten]

Lol. the muffler my 89 sentra i bought when i broke my ankle to get around since it was a auto had its muffler explode. scared the shit out of me, but i laughed so hard when i saw a guy jump to the ground :).

[banzai510(hainz)]

Very descriptive LONG post on what you said but you didnt say what type of distributor you have.

 

Let down to the nitty gritty. get a timming light !!!!!

Now open up your distribut and see if it wiggles side to side. Now if this is a point distributor it could cause the points to open when they are not supposed to. Meaning the bushing is wore out. But this usaully happens ove time so gradually becomes worse.

Or a condensor can become bad also causing BLOWING up of mufflers.

 

after you ck that time it with a light . If timming is eratic then its in the distributor.

[datsunaholic]

Last time I blew up a muffler (on the freeway) it's because my coil (-) lead, which goes to the points, was getting grounded out cutting off ignition. Loaded the exhaust with fuel and when the problem rectified itself (tach lead was hitting the clutch pedal arm) it refired and all that fuel in the exhaust blew up.

 

Worn out points or a worn out distributor (shaft wobble) will do the same thing, and make it run like crap. A failing condenser as mentioned above will do that too. If electronic ignition, a module failure will do that. Too many variables not knowing what you have.

[astro_ss_340]

most likely an ignition problem as stated above, but I also had this happen with a worn out carb, it was flooding out and filled my muffler with gas and proceeded to backfire as the engine was loaded up with too much fuel

[Roadracer Al]

Also possible that the timing chain skipped one or more teeth.

 

I don't know if these are interference motors, it could be just as easy as popping a new timing chain on.