Thread: engine fire

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OK Ive got a serious problem.

two engine fires in two days. No apparent fuel leaks from the carb (holley 600 vac sec).

Been running it for two months with no problem. Had some water in the fuel and caused the truck to shut off. got it cranked and up in flames it went. got everything cleaned up and made sure I had no leaks and no fuel sitting on top of the engine. cranked it up. ran it down the road. ran rough @ low rpm's but with no other problems. let it sit for about an hour and tried to crank it. cranked fine and then up in flames again.

Could there be anything iternally in the carb causing this, or do I just have a fuel leak that I just can't see.

all thoughts welcomed...

Hi Josh, Ill take a guess that your dis. timing is slow and the spark is going back in the intake. Any how try advancing the timing.

man with that many fire's I would think that truck was trying to kill me

the carb could be dumping drops of fuel in the intake runners . instead of a vapor mist that should be cumming from the carb.

check you'r distributor and make sure the timing isn't erratic, and with engine off and a good bright flashlight look down in the carb and open the choke. , move the accelerator to wot and see how it's spraying fuel.





or if you believe in those sort of things , maybe it's possessed

thanks for the responces:

I looked at the carb: pushed back the butterfly and two huge streams of fuel dumped in. Not from the bulls eyes but higher up from two holes on the inside front of the carb body. That definitely looks wrong to me... what is it and how do I fix it would be my next questions???

also could the water in the fuel have caused this problem to start.

PS: timing is at 13 degrees or so

The streams are normal, but you might be dumping in too much. There is supposed to be some additional gas sprayed in when you open the butterflies. I can't remember the exact term, but it's something like pump shot.

13 degrees sounds like a little too much. Do you get any knocking when under load?

Have you checked your float levels? If you've got them set too high you might be dripping fuel into the intake. That can also make for a rough low end too. Pull off your sight plugs to the bowls and check. If gas comes out of the holes they're set too high. I believe most holleys are supposed to be set with the level just at the bottom of the sight plug opening.

When you start the car, does it crank and start easy? (if there's not a fire) Do you have to pump the pedal much?

I'm guessing that you've might have the floats off, maybe too big a pump shot (I'd leave that alone until later), couple that with a bit too much advance and it's likely you'll have a fire.

I doubt water in the fuel could have caused this, but how did you get out the bad gas? Is your filter in good condition? I had some problems with a holley with the needle and seats getting bits of contaminates stick in them.

I don't think water in the fuel could have caused the damage that resulted in a fire. but a backfire could. a weak ignition coil , a bad plug wire maybe had crossed fire with another wire and caused a backfire . what ever caused the problem should be dealt with before you attempt to start the engine back up.

you will need to rebuild the carb, or get a replacement, do not run it as it is!

you used water to put out the fire right? you can remove the distributor cap , plugs and let the engine air-out overnight , most of the water should be gone, next check to make sure the water didn't crack the distributor cap, since you said the engine was running before the fire. electricity and water don't mix to well without something getting a little damage. there is a dielectric lube in a rattle can you can get from most auto-parts stores and you can spray under the distributor cap, to make sure the heat of the fire and water don't rust anything, but only spay a very small shot of it or you will need to wipe the excess off with a rag.

its a little tricky rebuilding a holley carb if its your first time so I would suggest either get someone that knows how or get a new carb.

you had 2 fires now so I'm sure you are wide awake by know and are very cautious, go the extra mile and check all wire's, hoses, and fittings for any leeks that can cause another fire.

I have seen what could have been some nice rides sitting in the bone yards that were victims of fire. don't let your ride die that way.

Joshua,

I gotta ask.....how do you know about the fire with the air cleaner on? The answer may help diagnose the problem.

the air cleaner was off. I had removed it so I could get the water out of the carb (more water than fuel was in the bowls). after getting the water out of the fuel tank, cleaning and drying the engine overnight, I then cranked it up and let it idle for about 10 minutes, blipped the throttle open in nuetral and then up it went. I am thinking that there has to be a leak, because while there might have been a backfire through the carb, the fire was not just in the carb, the whole engine was a flame. wires melted, brake fluid resevoir melted, hoses burnt through.....

I have never had anything like this happen in the brief two months that the truck has been running, maybe it is a combination of things.

I have decided to replace the carb and completely rewire or replace (hoses etc) everything under the hood

thanks for the thoughts

you blew out the power valve in the Holley. They are notorious for this, and anti-backfire power valve kits are available from Summit. either that or the floats are sticking.

Have the carb rebuilt ( with the improved power valve ) and get
your fire extinguisher recharged.