leadguy

About 2 years ago while driving at high speed my 1980 suddenly lost power. Like the earlier discussion (85RX7GS) there is vibration, but it doesn't seem to be from the engine. It feels more like it is from the exhaust. It's more like a droning like you get sometimes with an open window or sunroof on the highway.

Pedal to the floor the car only gradually accelerates. But, when started it sounds and idles fine. Even when revved it runs normally -when parked.

I have kept it garaged since, but now I am ready to put it back on the road. I hope it is just an exhaust issue. Any ideas.

Directfreak

iTrader: (2)

Clogged Exhaust,
Working on 1 rotor, or
Bad Carb/Fuel problems.

peejay

Either the muffler or the thermal reactor has collapsed internally.

A fun way to determine which is to unbolt the muffler and go for a test drive. If it's cured, it was the muffler. If it's still slow, it's the thermal reactor.

Bring earplugs on the road test.

V8kilr

yes racing said something about the thermal reactor/exhaust manifold collapsing,
also your cats could be the problem,
if you really think its the exhaust id get a new system,
if you find its your engine then what would be a better time to rebuild?
if the engine still runs and adles normal then it would probably be a great candidate for a rebuild,
chances are there is no internal damage,

peejay

'80 has no cats, it has a thermal reactor

leadguy

Thanks all for the tips. I think I'll give peejays suggestion a try, with the earplugs.

MIKE-P-28

iTrader: (1)

Whats the BIG SOB in the middle? They called it a heat exchanger but looks dead up like a cat..

peejay

It's a heat exchanger. It's like an inside-out radiator on the inside, if I had a working digital camera I'd take pictures.

Air from the air pump destined for the thermal reactor goes first to the heat exchanger through the external hose/pipe. In the heat exchanger, the air is heated up really good by the exhaust gases. The air then travels through the downpipe (it is two layers, the air goes through the outside layer) and finally to the thermal reactor, where it is put in the exhaust stream.

The reason the air is pre-heated is so that it works more efficiently. All a thermal reactor is, is an external-combustion unit. Thermal reactor cars are jetted to always run rich, so there is a steady supply of unburned HC's in the exhaust. Hot air is injected to provide oxygen to the exhaust to continue the burning process in the thermal reactor. Cold air could stifle or even put out the burning in the thermal reactor, so it must be heated.

It's a crude method of cleaning up the exhaust but it is HIGHLY effective. Unfortunately, the thermal reactor can collapse internally, especially if the airpump is removed. Y'see, the air pump also provides cooling air to the OUTSIDE of the thermal reactor, to prevent it from overheating under certain conditions. The strange little mini-exhaust pipe that runs alongside the normal one is the exit for the thermal reactor's cooling system.

79+80_rx-7

Then why/how does that little pipe that runs along the side of exaust on mine puts thick white clouds of smoke out, when the engine is above 4.5G or on start up ??? THANX LATERZ, ANDREW

peejay

I have no clue. Only dry air goes in there.

79+80_rx-7

Hmmm.... Could the thermal reactor be collapsed? Or could there be an exaust leak some where? THANX LATERz, Andrew