Fuel Injector Hydo (Fuel)-Lock

[michael.konor]

Got my #80 injectors cleaned, serviced, and flowed last week. Got them back from a reputable shop and reinstalled them into the car. Car started and ran just fine afterwards.

Flash forward 3 days...

I get into the car and hit the key... "THUNK". Car won't turn over beyond the thunk and stop. Have a spare battery, no change. Installed a spare starter, no change. So I start digging deeper, especially since I'm about to install my new high speed Zimmer's Hotside Turbo setup, as well as installing new camshaft chain parts while I'm at it.

After the thunk, I know I've got a problem mechanically, so I pull off one of my hotside pipes and fuel POURS out of the car. I keep going and my engine is full of fuel.

I've attached two pictures. One is when I pulled off the vac hose off the back of the intake and fuel poured out, and the other is the fuel pouring out of the intake after I pulled the intake off.

After pulling off the intake, I removed all the spark plugs and cranked the engine. Well, you guessed it... looked like a 4.6l version of old faithful geysering out of my engine. What a mess on that first cycle. Stuffed rags all over the engine and cranked it until the fuel stopped coming out.

Of course, I didn't have a problem with the injectors doing this before the servicing. So, it's something they did or didn't do.

But what could it be? Is there some reversing valve inside the injectors that could have been reversed? What's holding them open full time that even when the car is off it's siphoning into the intake?

 

[JeremyH]

Yikes, I would contact who ever serviced your injectors immediatley!

 

[CPRsm]

FUCK, do a compression check and cross your fingers all the rods are still straight.

 

[michael.konor]

Compression check will be done tonight. But contacting the injector shop will be this morning!

 

[2006 vista blue roush]

Wow that is insane...keep us updated!

 

[michael.konor]

Update:

Yesterday while going through some other car stuff, I remembered that fuel in cylinders = fuel in crankcase! I slide an oil pan underneath and pull the plug and out pours a oil & gasoline concoction. From a 6 qt system, I drained out nearly 9 qts of liquid. Not good!

Immediately went down to advance auto parts and bought 15 gallons of oil and three new filters. Poured in the first 5 gallons equally through both valve covers. I also poured about 1 oz of oil into each of the cylinders which I knew would be washed down pretty badly. Since I have the intake off, I cycled the starter for 15 seconds, paused for 1 minute x 4 times, then drained the oil. I will have to say that it sure cleaned the hell out of the inside.

Rinse, lathered, and repeated two more times except that I cycled the starter for 1 minute x 3 iterations, then 5 iterations for the last oil change with plenty of time in between cycles to the starter time to cool back down. It was probably 1 hour between drains and fills to give everything a chance to drain out, especially working the oil out of the cylinders that I poured in earlier through the spark plug holes.

(Note: Make SURE you put rags on top of the spark plug holes and weigh them down a little unless you want an oil mist geyser...)

By the last oil draining, I couldn't smell any more fuel in the engine. But to check the level, I pulled out my fuel vapor detector and it barely blipped when I got it close to the drained oil.

So, I filled it back up with Mobil1, a new filter and began the compression test. All of my cylinders are between 143-155 PSI. My benchmark is the PSI test I did back in March that was 141-149. Little higher this time, so I'm guessing that's some oil left in the cylinders.

Dropped off the injectors with the service garage today for checks. He's figuring that some debris might have gotten inside the injectors to hang it open. We'll see...

 

[JeremyH]

Hopefuly all this work pays off and the motor isnt hurt when you go to start her back up!

 

[michael.konor]

Hopefuly all this work pays off and the motor isnt hurt when you go to start her back up!

That's my top concern.

 

[Fullboogie]

It really sounds like you did a good job of finding the problem and taking care of getting the gas out. My question is how can stuck injector(s) drain a fuel tank when the engine is off - it can't siphon because the injectors are higher than the tank. What the heck happened?

 

[michael.konor]

During the troubleshooting the starter problem (ultimately because it was fuel-hydro locked), I had cycled the key quite a few times while checking the relays, wiring and such. Also, I had left the key on for quite a bit of time.

Considering -8AN lines and two GT Supercar pumps, that's a lot of fuel with each cycle.

 

[Fullboogie]

Ah, that explains it.

 

[Bobby]

man that sucks hope you get it fixed with no problems.

 

[michael.konor]

All told between the intake, exhaust pipes, oil pan, and the geysers that came out of the cylinders, I estimate that there was nearly 2.5 gallons of fuel in there.

Beyond what I've already done, can't think of anything I could do except disassembling the engine. Maybe remove the coupler off of my air compressor hose and flow some 20psi air into one of the valve covers and let it vent out the other?

 

[michael.konor]

Got the injectors back Friday and no surprise to me, two of the injectors "popped" just fine, but were stuck open. They took full responsibility for any damaged caused by the hydro-lock. Nice thing to have a reputable servicer that takes responsibility...

Got the car 90% back together today. For those who missed it, I serviced the injectors, replaced my Hot Side of the turbo with the Zimmer's Performance Setup (which required modification of my cold side to match up the new pipe patterns), rebuilt and upgraded my 3650 transmission, and replaced all of the timing components under the timing cover.

Started the car and after enough smoke to kill every mosquito in a 1 block radius, she's purring like a kitten. Can't remember the last time my car was so quiet underneath the hood. Oh yea, the smoke comes from the oil I poured into every cylinder when all that fuel washed out the cylinders, pistons, and rings.

Though she's running good now, I can't help but worry about the long-term longevity of the engine...

 

[gil_t2]

Don't forget the exhaust sys, raw fuel may build up in the muffler and BOOM

 

[rford426]

congrats man sounds like you dodged a bullet!!!!!

 

[JeremyH]

Good to hear, hope all goes well!

 

[michael.konor]

Don't forget the exhaust sys, raw fuel may build up in the muffler and BOOM

Found nearly a quart of fuel in the exhaust system when I pulled it apart to install the hot side. Was talking to a fellow wrencher who has his '91 Fox Body in pieces next to my car (installing stronger engine) and we both laughed (now...) at what could have happened if all that fuel ignited. I'd be calling both my homeowners and automobile insurance companies...

 

[gil_t2]

Had a friend that had Hydro-lock on a 427 Chevy and blew out 2 combustion chambers in the heads

 

[michael.konor]

Update:

Got everything back together and the car started up just fine without any bad noises coming from the engine. Car idled good too. However, when I was out on the road the car felt very flat and I started getting the dreaded P0340 DTC.

Ran all of the troubleshooting you see everywhere, including replacing the alternator. No joy...

Pulled the valve covers and replaced both phasers with ones I had before. No joy again...

Said the hell with it and pulled the heads off last Thursday and dropped them off with a local machine shop during lunch today along with some spare parts I had (just in case). They finished diassembling one head and the total damage just in that one is two valves and one valve guide. Lucky for me I have the parts already and barring any complications, I'll have them back today along with a complete valve job. Luckily, the injector servicing shop has promised that they'll reimburse me 100% for the damage.

I also checked the piston depth at the bottom after setting it with my dial gauge. All of the pistons measured the same depth on the right and left sides. Good thing I've got a forged setup.

More to follow...