After I purchased my RX7 FC, it needed new front wheel bearings, clutch master cylinder, slave cylinder, and a passenger seat. I got everything installed and ready. I’ve started it and had it idling at temp six times now, and I was ready for the first ever drive test. Our new gas in and for the first time it didn’t start. Couple pops every now and then but wouldn’t keep going. Soon enough, fire broke out underneath the vehicle. Luckily I was able to throw snow on it and put it out. Fire only burned for about a minute under the engine and I couldn’t see any visible damage. Any specific parts I should check? The fire started because a fuel line somehow disconnected and dumped gas on the ground. Once the engine backfired, it ignited the fuel. I have open headers and a turbo ll rotary currently with no turbo connected. I’m afraid to start the engine again without checking all the sensors and wiring for damage. Also I’m thinking maybe the new fuel cleaned out gunk holding the fuel lines together and that’s why it failed?

 

You probably flooded it and the exhaust had fuel in it which leaked out and 💥

 

Edit: This post was useless. You say your hose came off? Was is because there was no flare on the line? Or perhaps you had the lines backwards and the pressure blew it off?

 

Are you certain it was a fuel line or did the pulsation dampener fail?

 

Okay I’m unsure what happened now because I realized I mistook another line for my fuel line. The fire started under the air intake by the injectors I learned after my friend told me what he saw. The only damage is to some vacuum lines and some other lines that I’m unsure of their purpose. Can someone tell me what the circled lines are for? Ignore the snow as it was all I had to put the fire out

 

Those look like the oil metering pump lines which squirt oil into the rotor housings.

 

Is this the pump you’re talking about?

 

That looks like it, yes.

 

Thank you. I got the oil lines ordered as well as the new vacuum lines and fuel lines. Hopefully the install will go well and I can finally drive this beauty

 

I would investigate that Fuel Pulsation Damper, it looks like that may have been the cause of the fire. They are known for this, and you can replace / delete it.

Good luck, post pictures when it's fixed

 

I’m new to this Rotary life and I saw that many people had problems with this and I was wondering how much would this cost or how difficult it would be to do

 

On an S4 rail it's as simple as unbolting the FPD and replacing with a banjo bolt. Very cheap and easy. I don't know what the cost of a new one is, as when my car was relatively stock/low power I simply did the delete.

http://fc3spro.com/TECH/FAQ/pd.html

 

Replainc the FPD is almost routine maintenance at the age of the vehicle. Many have lost their engines and cars to a leaking FPD. That's why I mentioned it above. Being thatvyoull have everything off of the engine, ensure you order another and install it and new crush washers on the fuel rail.

 

Finally got the 86 up and running. After we replaced the lines and rebuilt some of the engine, my friend stood and watched for fuel leaks while I cranked the engine. Gave it two revolutions and we found the original source of the problem. There was a small bolt on the end of the bottom fuel rail that for some reason had completely fallen off. Fuel was just spraying out of it. Didn't notice it at first because some of the pieces were charred by the fire. After mounting the bolt, I've had no further issues with the vehicle besides tuning. First drive was last week and it pulls like nothing I've drove before. Thanks everyone for the help. I've got some pictures of the vehicle in my albums. For those wondering, I've also deleted the Oil Metering Pump and I'm mixing oil at one ounce per gallon of gas.

 

That's the fuel pulsation dampener that you are describing. I've seen the center screw back out many times. I would recommend replacing the pulsation dampener. An engine fire is not something I would risk again.