jacob80

Our engine has a decked head and sum-1mm Felpro head gasket. What results has everyone else achieved with their motors? (Turbo of course)

Ok when I take the cap off coolant does come out pressurized. As far as the compresion test, it seems like every cylinder is about 135 and one is 145 and the motors has ~1000k miles on it. Stock boost has only been run and it is a fresh rebuild. The headgasket is a Felpro sub-1mm headgasket.

How do I go about pressurizing everything?

Thats a good idea! But unfortunately I changed the coolant and oil and it still seemed to overheat Perhaps the head gasket is blown. Small bubbles would pop up every once in a while in the radiator as I kept topping it off, is this normal or is this a definite sign of a blown head gasket? I want to be sure its the head gasket before I pull the head off and swap it. It makes good power but all these little symptoms are bugging me ugh!

Ok, little update, drained the flush chemicals and refilled with water and let sit for approximately 10 minutes with no overheating at idle, yes! Although, the fan never shut off after the thermostat told it to but atleast it didn't overheat. There was a consistent brownish tint throughout the flush chemical mixture that seemed to smell like that orange powder that are in fireworks, not sure what its called off the top of my head but didn't seem to smell like oil. Not waiting for it to cool off so I can put regular ol' coolant in 'er. In the meantime, I'm going to change the oil and look for anything abnormal.

Alright boys, I've wiped off the oil between the block and the head, drained my two-day old coolant which has turned a little brown and filled the radiator with flush chemical and water and am now waiting for it to cool down after my ten minute idle with the stuff in it. I will next be changing the oil and apparantly I'm looking for a weird color I assume? Or texture? Well regardless I'm looking for a change. I'll then replace the oil and coolant and see what happens. Hopefully it isn't a head gasket. We had the block hot tanked at the machine shop but when we got it back it DID still have a little rust inside the water passages, so we'll see. we JUST rebuilt the engine bottom end and everything, and its a Felpro sub-1mm head gasket, so we'll see what happens!

Unfortunately I would say that it was a smooth milky color (the coolant). We completely rebuilt the engine so I figured it would be ok but maybe not. Hopefully I'm wrong but all symptoms seem to lead to the headgasket. I just put in fresh coolant which I know is green so hopefully it will stay that color. Do you think it is possible for any remaining rust to turn the coolant brown again? The motor has probably around 1000 miles or so and the power seems good and smooth. Thanks again guys

Hey guys, Alright so some of you have seen my thread about my rebuild some of you have not but it seems as though we may have a little problems. Recently, we've noticed that our motor gets way too hot under idle for more than 5 to ten minutes. Also, I've noticed some possible oil in the coolant, so I flushed it and it was all light brownish but then again the coolant may have came that color or it could have been all the rust, even though the block was hot tanked but it still did have rust when we received it. Anyways, I have also noticed a little itty bit of oil between the head and the block. Is this a problem? Our compression test varys 10 PSI ranging from 135 to 145. Could we have a potentially bad head gasket on our hands? If you guys could, just let me know what you think, thanks!

Well we have the megan racing RRFPR, what would happen if we disable vacuum on it? Would it still work or not

So we have to buy a new regulator? What purpose does the vacuum line serve other than increasing pressure? I thought that was the sole purpose of it. Hmm....

Hey guys, we have a megan racing RFPR and have decided to disconnect the vacuum line to disable the rising rate part of it. For megasquirt, you don't need a rising rate regulator, correct? From my understanding, the rising rate regulators are for stock ecu wiring with turbocharged application?

Yes, we did everything in that small one car garage. We had to squeeze between the wall and car door to slip in. I wanted it to be like a walk through but the camera just wasn't a priority at times, I apologize. The turbo is stock and it is a pallnet barb fuel rail. Advice from me is do everything right, don't half ass anything because it is NOT worth it. Be clean about everything and just do research. From this point on you will be constantly reading, trust me. Good luck!!

Hey guys, just wonderin if a compression test of between 125-135 for a freshly rebuilt L28ET is good. The engine seems to be running great with no issues, except a couple small tuning issues. Just let me know, thanks guys!

Hey guys, recently, the brakes on our '72 have been pretty bad. One day I took a look and the fluid was low. I attempted to bleed the brakes only to discover that fluid was spitting out between the master cylinder and brake booster. Upon further inspection, the paint below has all bubbled and a little rust has started as a result. To fix this, is there just a gasket between the two, or do we need a new master cylinder all together? I've read that the 81-83 zx master cylinders are an upgrade? Just let me know guys, thank you!

So you guys go by the rotor rather than looking at the orientation of the top of the shaft as the book and FSM do? So as long as the rotor is facing straight ahead at TDC everything is good? We are having issue with this and need a concrete answer. Thanks guys!

Ok so apparently, the circuit is either blowing the fuse on the relay board for the fuel pump or the fuse over by the coil for whatever reasons, so rewiring will commence tonight. Thanks for all the help guys!!

Blown fuse was the issue, more on that later

Ok, problem solved, somewhere in some setting, the megasquirt is cutting fuel/turning off the fuel pump at that RPM. Where are the fuel cut setting in megasquirt where we can change this???

Exactly. Appreciate the help moby!

Actuall its really the only way we could make it fit. Otherwise, yes, we would make it shorter, thanks for the advice though!

Stock rebuilt long block L28ET Stock T3 turbo MSA downpipe Performance products front pulley Fidanza Flywheel Bosch 440cc 42lb/hr injectors (using PWM on megasquirt) Throttle body space with 240sx throttle body Front mount intercooler Megan Racing RRFRP Pallnet fuel rail Walbro 255 lph fuel pump MSnS (v3 board, IGBT triggering enabled) with relay board Upgraded Alternator (280zx turbo alternator) with MSA wiring harness plug

Ok, I take back what I said, sorry. Went for a test run and the FPR seemed to have no effect on our problem. The datalogging is showing when reaching ~2300 RPM from a slow, slow climb in first gear, it completely falls on its face , a slow pause, then followed by a backfire out the downpipe. We are running 440cc injectors with pulse width modulation, could this be a factor at all with the stock turbo? I'm sure the size isn't the issue but maybe the pulse width and/or duty cycle? Here is a pic of the datalogging where the event occurs: Any help would be appreciated, hopefully we can get a response tonight and see what we can do, thanks guys!

Ok, hold the phone! I believe it is our fuel pressure regulator. It is a megan racing RRFPR, which I believe is our whole problem. I think that we've been setting our fuel pressure around 40 at idle and when under load, accelerating, it is increasing fuel pressure in excess and dumping in more fuel than needed and creating a rich mixture. Yea, i meant rich, I only said lean because the AFR gauge would go lean AFTER the event, so it wasn't ever lean. We're about to find out if that was our problem. Should we even attach the vacuum line or can we just run the fuel pressure regulator at a set PSI and let the computer adjust the fuel flow through the injectors?? Thanks everyone!

Ok so our distributor shaft was off, which we fixed, and seemed to help nothing. Here is the issue: The car revs to 6500 rpm easily while not under load. First gear, just engaging the clutch, going about 10 mph and slowly climbing RPMS, 1000, 1500, 2000, 2500, all the sudden, the car seems to have no throttle response and seems to almost die, and a backfire immediately follows if you don't take your foot off the gas. The AFR shoots through the roof for a moment and then comes back down. Now, back down to 1000rpm. What is our issue? Is it something with the injectors? We have 42 lbs.hr Bosch 400s running PWM. Could comething with the PWM be causing something like this? Any help here is greatly appreciated, the car sounds GREAT, but doesn't like to go over 3000rpm.