L28ET smoking like crazy

[skylinedriver59]

Hello guys, I am posting in an upset mood. I thought I had my 240z project in the bag. I recently got my megasquirt 2 setup and the car was running but I decided to replace my head gasket with a metal head gasket so I took my head out and I sent my p90a head to get a valve job, and checked. I was later told that they resurfaced my rockers. I got the head back in and everything is running. but I was going to get the car dyno tuned but it couldn't be done cause the car was smoking to much its white smoke we are swamped on what it can be the only thing I have in mind is that the machine shop did something wrong. oh and I had taken the head complete and they gave it back to me with the cam and rockers apart in a bag. Well I dont know what to do give some ideas or advise cause i hate to give up on my z.

thanks
Manny

[300ZXttZMAN]

Manny don't give up on her!

The age old saying that everyone's Dad told them growing up: "Don't fix it if its not broke"

It seems like thats what you did you took the head off (while the motor was perfectly running) to go get valve work and have it ported and now its burning coolant.
White smoke = Coolant

I would guess that the machine shop didn't shave the head properly or the gasket used was kinked. In order to use a metal head gasket you truely have to have a perfectly shaved head with little to no imperfections. I suggest you try and use an OEM head gasket.

The point of a gasket in the first place is to ensure a good seal by correcting imperfections. If the machine shop is not 100% on point with what they do, how they do it and the equipment they use then they are not the people for the job..

Try to use an OEM gasket and let us know how that goes.

Good luck and don't give up.

[skylinedriver59]

Im not giving up on the car just on the Motor.

and sorry but i ment to put dark gray smoke, and my plugs come out black.

I did a compression test and I got 125 on cylinders 1-4 and 140 on 5 and 6.
I also did a leakdown test and I got 20% on most cylinders two of them were at 40% i think.
but I can hear the air coming out the crank case.

The car ran 250whp at 9 pounds of boost but we didnt want to push the car more cause it was smoking up the shop and I have other issues.

The machine shop that did my head suck we suspect they shaved my head probably top and bottom as well as my cam towers and didnt tell to shim them. oh and like I mentioned before they resurfaced my rockers.

[evildky]

larg plumes of white smoke = coolant
large amounts of black smoke and fouling plugs is a fueling issue
you said metal headgasket, was it a copper gasket of a MLS gasket?
what thickness?
new or used?
did you use copper spray ont he gasket before installing it?
did you upgrade to APR headstuds at the same time?
what torque procedure did you use? (the arps take a bit more torque)
how much as the head suprfaced?
surfacing the "rockers" (we actually call these "followers" as this is an overhead cam engine) shouldn't be an issue, the hydraulic "lifters" (or pedestals) will take up any slack which should be very miniscule)

now the plugs come out black, that would indicate a rich condition, you are runnign megasquirt, do you have a wideband? is the car in constant warm up mode? is the cts working properly? have the maps, msq, or ini files beel changed? who tuned it?

[skylinedriver59]

its a 1mm MLS gasket and it was new.
I sprayed it with copper spray and I installed ARP studs in three step procedure to 70 ft/lbs.
So you think the head should not be an issue?
The whole followers and cam towers being shaved shouldnt be a problem? or should I add shims?

Yes I am running megasquirt with a LC1 wideband. how do I check if the car is in warm up mode? idk if the cts is work properly. while on the dyno it was getting really hot thats why we pulled the car of the dyno. I got the running by myself thanks to you(evildky). But I then took the car to get dyno tuned at OSRdynotuning out here in CA.

[evildky]

how much was the head shaved?
did they machine bothsides or just one? (it's unusual for them to surface the top unless you ask for it if the bill saiys machined 2 sides it could have been the intake/exhaust gasket side as they have a tendance to pitt around the thermostat housing and the #1 exhaust port)
still running stock lash pads?
which key is the cam gear on?
there are a lot of variable on these heads, shimin the towers is rarely needed unless you do something radical

it's also unlikely that the machine shop got into any waterjackets unless they were doing port work, these heads have a lof of meat on the suprfaces sides

on your megatune you should have an indicator for warm up mode, as well as a temp reading form the real time display, what version of megatune/turner suites will determine where these are locates, on older versions of megatune the warmup was at the bottom of the screen and the real time display could be selected form one fo the drop down menu's, but that might be different depending on the turnign software you are running

so OSR tuned the car, and when they tuned it what kind of dyno numbers did they get and how does that comepart to your recent results? is it the same dyno for both tunign and your recent test?

[skylinedriver59]

Ok i talked to the machine shop and they said the only shaved the bottom and the shave the minimum. he said thats the only thing they shave or resurface because its part of the valve job. anything else is additional thats why they charged me to do my followers.
yes stock lash pads.
the way i took it off its the way i put it on.

Im running the latest version of tunerstudio.

YES same dyno.

[evildky]

I have no experience wiht tuner stugio, I hear it's a lot easier to use, but there should be some real time display that will allow you to see the temp readings form the cts and verify that it's getting good values

I just don't see how anythign in the course of a normal head/valve job could cause any issues, if you cleaned the block surface, used a mls gasket with copper spray, properly torqued head studs with arp lube I don't ee any reason to suspect anything wiht the engine, that and you said black smoke and fouled plugs which indicated over fueling

O2 sensor and CTS are the 2 main culprits for over fueling on megasquirt or OE injection, you'll want to verify that the realtime O2 readings are accurate as well, I know my LC1 wires differently to the gauge than it does to the megasquirt