Here's the deal. Lost the rear rotor while cruising along, have a 1979 model, looks like a mtc exchange motor (gray housings, factory had black) Weird thing is, I still have spark, and I'm pretty sure it still has compreesion (pulled out the spark plugs on the rear housing, and it still puffed air out of the holes) It doesn't make sense, it would have to have been an apex seal to go, but there are tell tale signs of that, and my car exhibited none of those. So, I've got spark, and I'm pretty sure compression on the rotor (didn't use a tricorder, just assumed when I saw air coming out when the engine runs.) Is it possible that there is some kind of fuel delivery problem? I was just driving casually, barely revving the car, and all of a sudden, there was a sort of rurring noise, and then I just lost power and pulled off to the side of the road. I'm thinking personally that the rotor just went, but it doesn't make sense that there'd still be air coming out of the spark plug holes, acting like the rotor is spinning. My car was running like a top, then all of a sudden, I'm on 1 rotor. There was no clouds of blue smoke or anything like an apex seal going out,sufficient oil in it, it didn't overheat, and I'm pretty sure the rotor is still spinning,So why am I running on 1 rotor?

Thanks,
SPEEDBOX

Oh, and the spark plugs weren't soaked in oil/gas or anything...if that makes a difference. I just hope it isn't new engine time already, and really hope it's just some kind of problem where the manifold is blocked or something

 

Are you absolutely positive that you didn't lose your leading ignition? Because that's what it sounds like.......

 

^ Disconnect the trailing (top) plug wires with the car running. If the engine dies or runs much worse, something is wrong in the leading ignition. If the leading ignition is working correctly, there should be only minimal change in power and idle speed when both trailing plugs wires are removed.

 

I'm leaning towards a blown motor since your description is exactly what happened to my motor 3 days ago. I was idling at a light when the idle got lumpy and i have almost no power. I heard the apex seals go out the exhaust and i have no compression on the front rotor. LOL!!
Oddly enough, it idles smoother and runs better at part throttle than it did before it blew. Hahaha!! Gotta love an out of tune Weber 45 DCOE and RB header with 2 magnaflows.

 

I had just about the same thing happen to me where I thought it was only running on one rotor. Traced it down to a bad pick-up in the distributor..

 

Just to be sure, yank the spark plugs from the front housing as well. You mentioned you pulled the plugs from the rear and things sounded alright, but compare it to the front.

If they sound the same, check for spark (you'll have the plugs out anyway, may as well make sure they're all firing and it's not an ignition problem).

I'd guess the problem would probably be found in one of the 2 above things (and I'd check them first), but in the event that it all checks out, it could be worth checking towards the fuel end of things. If you can get it running, look down the carb and make sure fuel's coming out both primaries. If it isn't coming out the rear primary, could be something plugged up in the carb, or maybe even a jammed shutter valve (if the engine's got one).

 

Hey guys, nvm this post. It died on me when I was heading to work, so I had my dad give me a ride, and he checked it out for me, and that's what he did and told me. I checked it out myself when I got home, took all spark plugs out, and compared compression, and the front one made a crapload while the back one barely had a "fhoohf" and all spark plugs had mad spark (considering they're about 100 years old each lol) Sucks my engine blew. Wtf could cause apex seals just to go all at once like that, though? that's weird, lol. Anyways, now that I have no motor anymore, I do believe that it's 13B time, baby! Along with some peripheral porting and a weber, RB header and high output fuel pump. The only sucky part is that I don't have a car now and I'm broke, so I gotta buy a beater car for the time being. Oh well..ha