This morning when I got in to go to work, the battery wasn't strong enough to start the car. Had lights and radio. I hooked up the charger which has three settings, 2 amp trickle, 12 amp fast charge, and 75 amp start. I set it for 75 amps and let it sit for about one minute. When I turned the key, it started right up, so I disconnected the charger as quickly as possible. After I moved it out of the way, I started to close the hood and smelled gas. I revved the engine and everything sounded okay. I stepped to the back of the car and noticed gas pouring out of the exhaust, quite a bit on the right side and a little less on the left side. I revved it again and thought that the car sounded a little weird this time. I shut it off and took the wife's van to work. Any ideas? My plan is to disconnect the battery and charge it independently of the car's wiring, then reconnect and see what happens. Is it possible I did something to the ECM?
Thanks!

 

STOP !

I wouldn;t worry about the battery until you finish replacing the fuel regulator !

Raw gas blowing out of the exhaust is serious and can be only 1 of 2 things...
A shorted fuel injection system......
or, the diaphram in the regulator blew and either the reg or the inj are pouiring raw gas into the cylinders. This leaks past the rings and contaminates the oil. Check your oil....it'll smell like gas and you may have TOO much.

Your battery is OK. You were forcing the engine to compress liquid GAS...liquids don;t compress in this universe. What was happening is the starter was forcing the engine to rotate against a cyl (or several) that were full of gas. If you got lucky and it was forced past the rings...you got very lucky. This is how rods get bent, pistons get broken and cranks broken.

Tomorrow, pull all the spark plugs and crank it. See which cylinders blow gas out. If its most or some each side, thats a fuel regulator. Pull the vac hose to the fuel regulator to check it for wet gas inside. Hopefully thats it.
If its only one or 4 on the same side, thats a shorted injector harness. A single shorted injector can yeild the same result, but the repair is the same. Replace all 8 injectors. This is as common as sunrise.
Your condition is called "hydro-locking". Being unable to compress liquids. The bummer is that when a cyl fires it CAN force the crank to rotate and compress another cyl full of liquid...which cannot happen, so something breaks. Good news is the battery is as good as new...

 

Thanks for the reply. Oh, crap, was my first response. Yes, the oil has gas in it. Since the car ran for awhile like this and started making some weird noises near the end, I can only hope that I didn't bend or break anything. I'll get on it this weekend and find out how bad it is.
Thanks again!

 

There is an upside...if you broke something it would have happened instantly. The very first revolution of the crank under power. The weird noises were probably the engine stumbling and choking on pure gas being poured into 1 or more cylinders. Its takes less than 1 drop to create the right air/fuel ratio. When you give it an oz its gonna object and do strange things.

As long as there is ANY air space in the cylinder it will most l;ikely survive. That starter struggling was actually squeezing the gas past the piston rings and down into the crankcase.

The biggest concern is the gas in the oil thats destroyed the oils ability to lubricate. Running for more than a few seconds will result in severe damage to bearings and cylinder walls, like it was run without oil.

There is no point in draining the oil right now, its already circulated in the system..but as soon as you ID the problem and fix it, change the oil twice. Drain and refill with cheap 30wt, run it a few minutes to an hour then drain it and refill with your usual brand. If there is still a smell of gas you may want to change it again sooner than the usual 3000 miles or where ever you do a service.

The regulator diaphram is less than $50...if thats the problem.
If its shorted injectors thats gonna cost $250 from FIC but his kit comes with all the gaskets, all the O-rings and his cell number if you have a problem. FIC Jon has the absolute best customer support in the industry.
If its a shorted wire harness you might get off cheap...if you can find it. IF it has to go to a shop, find an Auto Electric shop.

Hope this helps.
I'm sure it'll be ok. Just part of owning a C4.



...the joys of being cooler than everybody else

 

More then likely the gas was not gas and just water coming out of the exhaust from condensation. You cannot compress gas so adding a higher power setting and getting it to start does not point to gas in the cylinder. Pull the vac line to the fuel pressure regulator turn the key on and see if gas comes out of the vacuum line. If there is no gas replace the battery, if there is gas then replace the diaphram and change the oil.

 

Oh, it was gas. I've seen condensation and at first, that's what I thought, too, but the volume and the smell and the feel all convinced me it wasn't condensation. It was like waves coming out of the exhaust.

Given that the car was fine Friday night when I shut it off and then wasn't fine when I went to start it Monday morning, any guesses on which one is more likely? I guess mice could have chewed on the wiring over the weekend, but it seems more likely that the diaphragm was bad to me.

 

Probably the diaphram. Not a big deal, more of a PITA than anything....

 

Now that I think about it, the oil on the dipstick has looked kind of funny the past couple of times I checked it. More opaque and brown than usual. Probably been leaking gas into the oil for awhile now.

 

Well, bad went to worse. I replaced the diaphragm, which had a big tear in it. It looked like the spring got cockeyed in the housing somehow, or that might have happened as I was taking it apart. Thank the Corvette gods for making me come back and check before pulling the fuel rails. It looked like I could just replace the diaphragm with the FPR in situ and such was the case after I went and bought a set of tamper resistant Torx bits. I put everything back together, pulled the plugs (which was a real pain in the butt and turned out to be totally unnecessary) to blow any gas out of the cylinders, drained the oil, changed the filter, and fired it up. It started right away, but is now blowing huge volumes of white smoke.

I'm assuming this can only mean blown head gasket. However, if anyone reading this knows of anything involved with removing and replacing the plenum that could possibly cause water to get into the fuel delivery system, please chime in. If it is the head gaskets, my thinking is that with >130,000 miles and the gas circulating in the oil, I'd be better off rebuilding the engine now than just replacing head gaskets. Given that the crank and block are still good, what would be a ballpark figure for rebuilding the engine if I do everything except the machine work myself?
Thanks!