hydrolock due to fuel wtf!!!!

[marley4us]

I have a S13 redtop SR20det, in my AE86 I have been working on, the motor is all stock except for Brian Crower 268 cams, and a Walbro 392 (external 255) fuel pump.

Got my driveshaft installed, wired up everything and went to turn it on... car would not start ( 2 days ago it fired up fine) . Tried again and the damn thing Hydrolocked, fuel injector somehow was not seated or I have no idea, since it worked before... but it dumped fuel into cylinder 3 and 4... I used a pump and got it all out, got new injector collars (seals) and went to turn it again. Put it on ignition and let it cycle with the fuel pump, and it was fine no leaking. Then I went to turn it on and it hydrolocked again! This time it wont crank at all... I'm F*&Ked... pretty sure i bent a rod. I have no idea what I want to do. I feel like I have been screwed by budda in jail with no lube, and he never even said hi or thank you WTF.

I pulled the head off and took as much as I could off the block to check it out.


I am so confused right now. Pulled the Ae86 apart, head looks ok, motor still wont turn over manually feels stuck. I could not get a motor lift so I could not check the rods, but mostly the block did not looked scarred on the walls from what I could see. Injectors hold pressure, don't leek, and spray pattern looks good. We took them out the motor and charged just the rail on a external fuel tank and celica pump... maybe my walbro 392 (external 255) is too much? I am not sure how? I can't figure out why it floods cylinder 3 and 4... when in the motor. yet after its removed it would not? any ideas anyone?


Please help this thing is almost done and I am so confused

[Dan3312]

So I realize the motor ran before but I am going to throw anything out there that might be doing it in my mind.

1) Wiring issue causing them to stay open and flood the cylinder
2) Injectors stuck open. Throw them out, replace them (not a huge expense considering you're replacing the rods as it sits)
3) Leaking injectors from the seats means fuel on the motor not in the motor
4) If you can't turn it by hand with the head off, the rods are bent. You can probably force it backwards. Forcing it to spin farther will cause more damage.

I'm sure I'm forgetting something else I wanted to say but so far that is my take on what you've said.

[Croustibat]

Originally Posted by Dan3312

3) Leaking injectors from the seats means fuel on the motor not in the motor

On an SR20, a leaking injector gasket leaks in the cylinders and cause that kind of problem. It is quite common knowledge.

@OP not much to do i am afraid ... I think you now have 2 problems.

1/ potential bottom end damage caused by hydrolock. Not much to do but check it.

2/ injector / injector driver/injector gasket problem. You seem to have tested with another set of gaskets, so it should be something else...

Are you sure about your ECU -> injector wiring ? Maybe there is a problem here, and the injectors are stuck open. You could also check in the ECU ( injector drivers are in) for traces of burn or patch repair, sometimes an injector driver fries and dumbasses just connect another one instead of replacing it.

[di-devol]

Originally Posted by Dan3312

Wiring issue

Originally Posted by Croustibat

wiring

I've had this happen, fuel even filled up the intake manifold all the way to the throttle body. I blew my breakers instead of braking anything.

It was a wiring problem.

[marley4us]

ok thanks guys, i will try to see if i botched the wiring. thank you, I will keep you updated.

[WalbridgeAuto&Performance]

Had a similar issue, it was the ecu.

[marley4us]

Thanks, ya I am pretty sure one rod is bent, maybe more. so I have to replace the bottom end. that I am for sure.

But the injector issues I will need to look into, i will test the wires and check the ecu today...

[the head]

make a noid light to test the drivers you need a small dc bulb and two wires stick the wires into he injector plug and crank (fuel pump off). If the light blinks they are good, If the light stays on they are spraying fuel constantly, if the light never turns on they are not opening. When mine hydroed it was a blown injector driver on the #3 cyl this was how I traced it.

[marley4us]

how did u turn the fuel pump off? just disconnect it?

when i tested the injectors with a bulb before, when cranking they would not light up, but they had constant power 12v, so if I grounded it it would... but it did not light up under crank. I will test it again

[Croustibat]

The ECU uses a power transistor to command the injectors open by grounding them, so it is normal they have 12V at the plug. Usually, the power transistor burns in the ECU and burns the wires around it. You can fix it, it costs less than buying a new ECU. It is a bit of a pain though, but any electronics enthusiast can do it.

You surely could not see it light up when cranking because the pulse is very short at that time. We are talking maybe 1ms commands.

[marley4us]

Just got my first day off. so I started working on the car. No i did not get to see it flash, but maybe the bulb i was using was to big, it was a old brake light bulb....next time I will use a LED, but when I test the injectors they do fire.

well I plugged the CAS and the injector clips on, held the injectors out and turned the car to on (mind you the head is off the car). Then I turned the CAS, the first turn, it would fire all the injectors or sometimes two at the same time? is this normal? after the first turn if I kept turning it it would fire in the correct order one at a time with a good spray pattern and no leaks at all....



I am still confused how it leaked in the first place. The intake manifold was full of fuel, pulled the head, and the block out, drained the oil, and I am pulling the pan in the morning and looking at the bearings and the rods etc.

[Croustibat]

it looks like everything is working fine. The reason the injectors fired all at the same time is that most (if not all) ECUs have cranking strategies involving batch fire.

It then switches to sequential firing, and when the conditions are reached, go back to batch fire. That usually happens at 50% load, around 3000rpm. It also injects twice per cycle instead of once when going batch fire.

I know SR and CA ECUs do that, i guess all RB and VG ECU do that too.

Anyway it really looks like your ECU is working fine, so it could be sticking injectors or leaking gaskets ...

What injectors are these ? Do you have a piggyback or something between the ECU and them ?

[marley4us]

They are OEM s13 injectors in a oem rail, no piggy back or anything. I put this motor as stock as possible to avoid problems with the swap...lol

Thanks. I did not know they batch fire, that makes a bunch more sense!


I ordered new injector pintle caps, two are cracked and beat up, but I heard the caps do not matter, and some people dont even run them. but I ordered a whole new set of them anyway, and new o-rings again so when i pull the injectors I have a extra set so they seat perfect....

[marley4us]

pulled the beast out


good by SR


I think this might be the problem lol!!!


Put everything else to the side




Even gave it a little color


Got new (used) rods, and BNIB rings

[Croustibat]

That was fast !

Double, triple check next time you try...
Bit of info you might find useful in troubleshooting that :
Injectors Priming/Spraying when Key in "ON" Position - Nissan Road Racing Forums

and from this one :
Injector leak causing engine lock up!!!! : SR20DET Forum (rear-drive)

Fuel is getting past from the O Rings not seating properly. Check the plastic collar that the O Ring seats on. I bought used injectors once before and the collar was bent on one making the O ring blow out repeatidly and leak gas horribly bad in the cylinder.

[marley4us]

Im giving it my best to keep her and make her go!


Went to Toyota Fest today, once we left, started rebuilding the whole motor.
With adequate supply of water and beer in the tool chest.




Problem child was replaced


with a New used rod


Brand New rings where installed





Wrapped my Downpipe with heat wrap.


Installed a SARD Fuel Pressure Gauge I had laying around



Honed, then Installed the pistons and rods back into the block.


Then Time just to reinstall and torq down everything.






















Lol this is what happens when a bunch of hot drunk girls (my neighbors come home at 1am).... car gets abandoned lol....tools still in place!!! lol



The Valve Cover got fuel on it, and ruined the paint, so I sanded it down, and gave it a new look.



Might as well make use of the sticker I have to paint over now... with A touch of color


Peel it off








All Done, Going to Install it back into the car tomorrow... fingers crossed.

here are some sexy pics of the car to end with for the day with the Battle-Garage One off Carbon Fiber Fender flares!

Fenders need to be pulled more

[KoukiMonsta]

Get this build thread in the build section lol

Glad things look to be turning out well.

[marley4us]

I tried twice, and it said waiting for mods approval... it never got approved lol.



Got the motor torn down, put BNIB rings, new used rods etc, BNIB o-rings and injector caps. a SARD Fuel Pressure gauge I had sitting around.


Installed the motor last night, going to finish reconnecting all the wires, pressure test the fuel system again, then start it up today.... fingers crossed... i need this to run.

[supersayianjim]

What ever became of this?

[jedi03]

check his other threads maybe this is 6 years old lol...had buddy do same was super fun!