Bogging and detonation issues!

[spooled240]

nah i don't think so, I've been running that blow through setup for about 2 years with no problems. Everything seemed to go downhill after i installed that walbro fuel pump. But it might be the blow through, who knows

I'm not really that upset, stuff happens and it's all fixable

[kouki_hmongster]

nah i don't think so, I've been running that blow through setup for about 2 years with no problems. Everything seemed to go downhill after i installed that walbro fuel pump. But it might be the blow through, who knows

I'm not really that upset, stuff happens and it's all fixable

I say Racing piston and rod FTW.

here's what i think happened. you probably went on the lean side and during hard acceleration BOOM!!! since your strainer came off that means that it's bad to be running on low tank, probably caused you to have some bubble in your fuel line leading to a lean ride at some point. makes a lot of sense, can be why it's the last cylinder taht went bad instead of the common cylinder 1 that usually blow. fuel rail flows from first cylinder to last cylinder, probably starved the last cylinder.

GL

[Razi]

Very good observation, makes a lot of sense.

I'm paranoid and will check my Walbro pump tomorrow.Maybe even get a fuel pressure gauge.

I like your attitude Josh, everything is fixable. LOL

[spooled240]

^thaz right mang

That's what i think contributed to the problem but it was constantly pinging on high boost even with a full tank. I threw the stock pump back in, changed my fuel filter and it still pinged at 11 psi

I'm pretty sure it had to do something with insufficient fuel flow but even back on the stock fuel pump and a brand new fuel filter? I know the stock pump can handle 11psi of boost cuz i daily'd my car on 13-14 psi on the stock pump before.

Maybe my #4 injector is bad or my FPR took a dumb from the walbro's high fuel pressure

[sunnys14]

I've been using the stock FPR on my car for over 25k miles with a walbro pump. Never had a problem yet.

Detonation sounds like rattling under the hood, it has a very distinct sound.

#4 cylinder is low on compression so i'm pretty sure your rings are done for that one due to detonation.

Something easy could have happened like your #4 injector plug could have come loose while you were boosting and that cylinder didn't get enough fuel and that's where the detonation came from.

[480sx]

I'm not really that upset, stuff happens and it's all fixable

Exactly dude.

Sorry to hear, but in reality its a great experience pulling a motor, rebuilding it, ect ect. Gotta pay for most educations heh. You gain tools you can use through out the rest of your life in doing so.

What most likely happened is this. You were low on gas(1/8th ish tank) and the strainer had fallen off since your last fill up. You started sucking up air into the pump, and when you went WOT your first 3 injectors gobbled up the fuel while your 4th injector got starved because of your fuel pump picking up air.

[spooled240]

true that, whatever doesn't kill you makes you stronger and i believe that you get something out of every situation and lousy experiences.

I still have to check my fuel pressure, I ordered a small 1/8" NPT port that will couple in-line with the fuel lines. I was thinking that a wideband would probably not have told me how lean i was running because it takes the average of the 4 cylinders, and not an individual reading. But yeah, I'm guessing the fuel pump got smoked from running dry and/or sucking debris from the bottom of the tank.

What I'm gonna do when i have the time is do a wet test to be 100% sure that my rings are shot on #4-pull my head off and do the valve seals.-pull my oil pan off and re-seal it on(currently leaking)With those off, I can undo the end cap on the rod and pull the piston out through the top of the engine. Then mic the bore and the piston and if everything is ok, Ill just slap some new rings on and call it a day.

[480sx]

If your gona do the pan you might as well just pull the motor. Much easier to do if your pulling both the head and pan.

[spooled240]

pulling the pan isn't that hard imo, just takes a few hours of some patience. Pulling the engine just seems like a real pita =/

[sunnys14]

For me, I'd rather pull the motor than to do an oil pan while still in the car. I can pull a motor faster than doing the oil pan!

[kouki_hmongster]

+1 take the motor out and your life will be a whole lot easier. IF you confirm that it is blown which most likely it is. then you would have to get the cylinders honed and everything. SO to save you from future ring failure, upgrade those piston, rod, bearing, etc... and later on if you decide to go 400+whp you can just up the boost.

[spooled240]

yeah i see. The thing is I'm not planning on running more than 300 rwhp TOPS (more like the 270whp I was at around 11-12 psi) so the stock internals will suffice. It's not that I'm lazy I just want to keep things simple and somewhat cheap at the time being. Who knows, I might end up pulling the whole thing out

150 psi is what i got on the other 3 cylinders which is still pretty good right? I had virtually no oil build up from blow by when my engine was still good.

[oz240red]

Hey man, sorry to hear about your engine. My car will be set up almost the same as yours, my ECU is now at JWT getting reflashed and I'll be using 555cc's.

In regards to the work you're going to do, let me share what happened to me. When my car was N/A it had a bad oil pan leak. I didn't know that you could change that gasket with the engine in. It look impossible to me, so I took the engine out. When I put it back in the car was as dry as a new engine for months. When I went turbo, I took out the oil pan to weld the bong without taking the engine out. Well, no matter how careful, when putting the oil pan back in, the gasket always moves a little or gets dirty, or even if you use a little glue it comes a little loose on the corners.... in other words, it won't be as tight as changing it with the engine outside where you can clean all the residues with brake cleaner, properly distribute the glue, etc. I have changed the gasket twice already with the engine on, and it hasn't been as tight as the first time.

Since you're going to remove the head and oil pan anyways, you'll just have the block, and once out removing the transmission is cake. Plus you'll be able to inspect the cylinder walls if there was any serious damage. Might save you some troubles later bro.

Good luck

[spooled240]

yeah that's true, I took my oil pan out to get the oil drain pipe on and it is easy to mess up that fresh bead of RTV sealant on the pan, mine has been leaking a bit =/