vetteguy216

Engine hyrolocked due to too much in cylinders, need to find out why/how it got there.

The Timeline
1- Car is running fine
2- Swap ecms with one from a 93 so I can test it and make sure the ecm from the 93 is working properly.
3-go for a 10min test drive. ecm appears to be fine
4-but the original ecm back in.
5- Several hours later start up car to put it in the garage and it seems to be running rich. I park it and go to dinner.
6-Come home go to start car and wont start, there is now fuel in the cylinders.

Before I swapped the ecms to test the one from the 93 the car ran perfect now different story.

What could have caused there to be that much fuel in the cylinders?

cv67

Check your injectors and regulator to make sure they arent bad

If you have a fuel gauge attach one to the schrader valve (looks like a air fill line for a tire) on the fuel rail, pressurize it and shut the car down. Keep track of how long/much pressure drops its a start.

car5car

All injectors cannot leak.
Check which one is leaking. Pull plugs, disable ignition, turn engine

STEVEN13

Check the FPR. Pull the vac line and check for fuel or fuel smell. This happen to my 92. Good luck!

Steve

mtwoolford

here's another timeline:

work on my 96 on the weekend; put away tools, let car sit;

following weekend, go out to start car BUT FOR SOME REASON, check oil distick first. The level on the dipstick is up to the top... OF THE DIPSTICK.

Drain what used to be oil, but is now gasoline, slightly diluted with oil.

Pull injectors, original multiteks, one single injector, drip, drip, drip. So it can happen. Pulling injectors on a LT engine is easy...on L98s I hear it ain't so easy, good luck

surfer92

Ok, list EVERYTHING you have done in the order you have done it.
You already had a thread going, why start a second?

Which car ran good before the ECM swap, 92 or 93?

If you are not getting fire, you can flood the car and not have a fuel problem.

vetteguy216

Before the ecm swap the 92 ran perfectly fine and the 93 had a miss at operating temp. swapped ecms and eproms test drove the 92 with the 93 ecm for 10min, and 92 ran fine with 93 ecm. Put both ecms and eproms back in original spots. and now 92 is hydro locked and 93 still has same problem.

cv67

Ck the regulator first then the injectors. If one of them is bad may as well replace the rest they probably arent far behind

vetteguy216

Ohm tested all injectors and they were between 12.3ohms and 12.5ohms when cold.

Hooked up a fp gauge and turn key to on pressure jumps to 40psi than falls all the way down to almost zero.

Pulled vacume hose on the fp regulator and it no gas in there, so it appears to be good.

Im just worried something might have happened when I swapped ecms. because the ecm that is in the car right now was perfectly fine before I put the other ecm in to test it. And I made sure to make sure the right eprom was in the right ecm. but I tested fp with the injectors plugged in and unplugged it was the same up to 40psi and then it fell. Makes me think it is bad injectors.

John A. Marker

Did you pull all the plugs? Do all the cylinders have fuel in them or only one or two. If just one or two then a leaking injector. If all, then I would suspect that you are getting a short somewhere which is firing all the injectors....hence your rapid fuel pressure drop....and filling the cylinders.

You will probably need to change the oil. I would also squirt some oil into each cylinder before replacing the plugs and turning the engine over a couple of times to get oil back on the cylinder walls.

vetteguy216

I believe only a couple leaking 7,8, and maybe 6. But if the injector electrical connectors are not hooked up to the injectors and fuel pressure still drops I suspect that there is not a short and that some injectors are bad. Is this thinking correct?

John A. Marker

No electrical power to the injectors and the cylinder still fills with fuel....I have to believe that the injector is leaking and it is NOT an electrical issue.

vetteguy216

Thats what I thought. Im just revealed its not an electrical problem. The car has 130,000 miles and these appear to be multec injectors.

John A. Marker

Probably time to replace the injectors. I recently replaced mine with new Accel's. I had changed mine out 6 years ago or so with Accel's. The picture shows the new Accell with three nozzels vs the old with a single outlet.


Or try Jon at Fuel Injectors Inc. for the new Bosch III's.

surfer92

That is really low for ohms on the FI's, you can contact Jon at FIC.
I had no luck w/BoschIII, but some have. 92-93 use 22 lb inj's and the III's are 24.

did you pull codes?
Check all harnesses for broken or cracked wiring, recheck the 92 ECM harness, you might not have seated it correctly.