Exhaust exploded

[brainhax]

Hi there,

Checked coolant, oil etc, Warmed up the 80 and went for a test drive. In 3rd gear lost power heard a big bag. I can see the exhaust is exploded underneath. I was pushing it a bit on a dirt road in 2nd and 3rd gear. Before driving It reved good and idled for long without issues. No smoke on cold start this morning at all.

1fz-fe, 1997, Manual

 

[brainhax]

All I learned so far that it happened due to unburnt fuel in the exaust. I think the connection between distributor and ignition coil was too much cooroded at the coil's end and while driving the connection gone bad, causing the exaust to explod due to unburnt fuel.

 

[Marvelicious]

Maybe a sticking injector?

I was going to ask about the ECU throwing codes, but I know some of the Aussie rigs have different engine management. No O2 sensors I'm guessing? For it to be running rich enough to cause that, a north american rig would throw a code.

 

[brainhax]

Maybe a sticking injector?

I was going to ask about the ECU throwing codes, but I know some of the Aussie rigs have different engine management. No O2 sensors I'm guessing? For it to be running rich enough to cause that, a north american rig would throw a code.

No codes on the dash so far. O2 sensor is no where to be found in my 80, I have checked in the past.

 

[Marvelicious]

Yeah, that's what I thought I remembered about the Aussie rigs.

Seems like with coil corrosion, you would have noticed a misfire happening. A stuck injector could have been a bit less obvious. Either way, if you're dumping enough fuel to blow up your exhaust, you need to get to the bottom of it. The excess fuel will wash the oil off your cylinder walls and cause accelerated wear, plus it can't be helping your mileage. Also, the whole exploding exhaust problem...

 

[brainhax]

Yeah, that's what I thought I remembered about the Aussie rigs.

Seems like with coil corrosion, you would have noticed a misfire happening. A stuck injector could have been a bit less obvious. Either way, if you're dumping enough fuel to blow up your exhaust, you need to get to the bottom of it. The excess fuel will wash the oil off your cylinder walls and cause accelerated wear, plus it can't be helping your mileage. Also, the whole exploding exhaust problem...

Will it be dumping fuel when idling if the problem persists? I see water being dumped though but it doesn't smell like fuel . The chasisse next to the blown exhaust is getting wet.

 

[Brindleboxer]

Agree, this isn't good. Could it possibly be associated to the other issue you asked about on Monday? I would say Yes, start looking for the coomon link.

That’s proper exhaust detonation, not just a failed muffler.. the bang you heard point to unburnt fuel igniting in the exhaust after a severe misfire or a timing issue. The earlier bogging and loss of power fit that too, and the “white smoke” under the bonnet was likely exhaust/backfire gases rather than coolant. I wouldn’t drive it again until the root cause is sorted, otherwise you’ll just cause more damage. I’d be looking hard at ignition and timing control (coil, igniter, distributor, ECU/wiring) and also checking fuel delivery (FPR/injectors) for over-fuelling. The exhaust is the victim here, not the cause.

I would agree with Pete and not drive again till you get to the bottom of the issue.

I would check your spark plugs aas well, they can tell a story the truck might not be wanting to. Also, test your plug wires and replace if not within spec.

 

[brainhax]

Today i removed the exploded muffler, and looked for any other damage caused in the engine bay and under the car. Couldn't see any heater lines after removing the muffler. Means there is no rear heater in FZJ80R. Kept the heater running in the car for long and car idled for long well.
The water dripping stops as soon as the car warms up, means its just the condensation that is changing into water when engine is started.
It sounds nice without the muffler, I wish if I could keep it that way.

Past story:
When ever I did a water crossing and the water was minimum to the ignition coil height, engine lost power and stopped. Car would crank crank but not start, throw white smoke out of air box filter and wont start. Airbox filter was dry as every time it happened. Then dont know magically after 1-2 hours of wait, it cranked and started... I think water was making its way to the coil, and killing the engine (there is no O2 sensor in my 80). see picture below.

Today, I cleaned all connection at the distributor end, none was as dirty as the Igniotion coil.
I unplugged the coil wire and tried to start, it would only crank and not start when the cable to the distributor is disconnected.
If the car is idling good for an extended periods and not throwing any white smoke, doesn;t it mean that there is no need to replace the ignition coil now?
When its idling or after reving, no fuel is found inside the open end of the exaust pipe. ( as the muffler is removed now)

------------------
1997 1FZ-FE, FZJ80R, Petrol

 

[LongDuck]

You have two threads on this same issue; should we keep helping you on both?

Thread 'Can a loose Ignition coil cable cause power loss'

Apr 20, 2026

Hi there,
I had to tow my 80 Series home today. Right at the start of a small climb, it suddenly lost power (bogging down), and smoke started coming from under the bonnet—definitely from the airbox. The engine would still start, but when I tried to rev it using the accelerator cable in the engine bay, it would lose power when revved hard.
After towing it home, I had a closer look and found a loose cable connected to the ignition coil. I’ve reconnected it, and now I can rev it hard in neutral using either the accelerator pedal or the cable in the engine bay, and it idles well too.

Could a...

• brainhax
• Replies: 31
• Forum: 80-Series Tech

 

[brainhax]

You have two threads on this same issue; should we keep helping you on both?

Thread 'Can a loose Ignition coil cable cause power loss'

Apr 20, 2026

Hi there,
I had to tow my 80 Series home today. Right at the start of a small climb, it suddenly lost power (bogging down), and smoke started coming from under the bonnet—definitely from the airbox. The engine would still start, but when I tried to rev it using the accelerator cable in the engine bay, it would lose power when revved hard.
After towing it home, I had a closer look and found a loose cable connected to the ignition coil. I’ve reconnected it, and now I can rev it hard in neutral using either the accelerator pedal or the cable in the engine bay, and it idles well too.

Could a...

• brainhax
• Replies: 31
• Forum: 80-Series Tech

We can close this one.