1983 280zx turbo engine

[JSM]

No you can’t borrow my AC vacuum pump! Lol. That was great Dave!

[Captain Obvious]

1 hour ago, JSM said:

No you can’t borrow my AC vacuum pump! Lol. That was great Dave!

Haha!! Don't trust him not to drown it!    I think he may have earned his verb... 

"Don't DaveWM your ______."   (Insert noun)

[Dave WM]

you pump got DM'd

 

[Dave WM]

fyi, I ran it and it seems to have survived despite my tool abuse 🙂

new oil in site glass looks nice and clear, vac was good, no odd noises. perhaps dodged the bullet, 

can I borrow you milling machine, want to try a new way of chopping up chlorine tablets for pool use...

Edited July 20, 2022 by Dave WM

[Captain Obvious]

39 minutes ago, Dave WM said:

you pump got DM'd

Haha!!! I'm going to do my best to make that stick now.  And good luck finding someone to let you borrow a mill.      !! 

And glad to hear your pump seems to have survived the ordeal. I'm not surprised. It's not like you ran it for an hour with the milkshake in there. Just a couple seconds and you got it changed out now. I'm thinking it should be fine. Might want to change it again after a shorter than normal run interval just to be sure?

[Dave WM]

1 hour ago, Captain Obvious said:

Haha!!! I'm going to do my best to make that stick now.  And good luck finding someone to let you borrow a mill.      !! 

And glad to hear your pump seems to have survived the ordeal. I'm not surprised. It's not like you ran it for an hour with the milkshake in there. Just a couple seconds and you got it changed out now. I'm thinking it should be fine. Might want to change it again after a shorter than normal run interval just to be sure?

forsure, after next time I use it will just drain again. I did run it for a few minutes, oil looked clear, but oil is cheap so why not.

got the rest of the plugs in, demo video of using the tool coming. I did have one issue you may want to check on yours, the shoulder of the tool was just a tad wide for the plug by the oil sending unit. there is a cast in boss that is just a bit closer than anywhere else to the opening. My tool got hung up (will see in the video). Off video I went back and filed it for clearance, then used the tool again to make sure it was a flush fit. I also checked the depth of the edge of the plug to the surface of the block. It was close enough that I did not feel any need to touch up the tool, the block is pretty ruff and getting a precise measurement using it as a ref seemed silly. I am sure its within spec if I knew what they were on that.

[Dave WM]

I was able to find a brand new OE turbo oil feed line from Japan. Came it today looks like a perfect fitment when compared to the old one. All that is left to do is put the turbo engine on the NA test stand and install the dizzy and the intake manifold. I already attached a spare exhaust manifold , T stat housing, and alternator with fan belt and pully. Last time I ended up swapping out a lot of stuff from one engine to the other, this time I am going for a faster turnaround time to test. It will prob be a few days as its just so dang hot its hard to get motivated to do the heavy lifting of moving engines around. Will see how long I can hold out (Stimpy guarding the red button at the end of "space madness")

[Dave WM]

good news bad news...

good new is I got it all back together, no more brown anything including foam. Bad news same thing with the exhaust gases in the rad. I just cant figure out where its coming from. I looked at the block cyl walls when it was all apart, no cracks, it would have to have a crack there for gas in water jacket. The head also looked fine, again no cracks. This leaves the gasket as the only culprit (or warpage the gasket can not handle). The test with the straight edge were well within spec, and there were no defects noted on the sealing surfaces (block or head). So my only guess is I did not properly prep the surfaces and/or did not torque correctly. I retorqued after the inital run to 65ftlbs in the correct sequence. they took a tiny bit of torque. tested again, same thing green then pale yellow. I confirmed the test kit on the good engine so I know my process is correct. 

Next up will be to pull the head again and try a different gasket. I have an NOS aftermarket gasket, looks like asbestos infused, will try again with clean surface prep and torque sequnce in 3 stages. 

If that fails I my just bag the project for now, or maybe try installing the turbo on the good engine with the MN47 head. 

Other interesting news, I installed an O2 sensor in the bung that is cast into the manifold I used (had to plug it anyway). hooked up my analog VOM (simpson 260), and was able to get the voltage right at .5v by adding a bit more flap (just push it in) while running. I seems the setting is a bit lean, I may have some vacuum leaks or maybe that is just the way it is. the voltage .5 during the start up (when the enrichment is higher on a cold engine) but tapered off to near 0 as it warmed up. Adjusting the idle blead did not help (again vacuum leaks were probable). anyway the vac was about 15hg when meter read 0 volts, manual enrichment to .5v and the vacuum goes to more like 18hg. Clearly a sign of a better A/F mix. 

the O2 is a cheap bosch single wire i think refered to as a narrow band, regardless I can see how something like this would help with setup of the FI on one of this old open loop FI systems.

I am thinking of coming up with a circuit that is 0v at .5v from the sensor with +/- as it goes from 0 to 1v, with a variable output voltage on the +/-.

that could be fed in series with the output from the AFM wiper, making a closed loop system with a single mod to the wire harness. IIRC an op amp maybe involved to allow for the +/0/- output adjustable for voltage so the correcting voltage could be varied in amplitude so as not to overwhelm the stock AFM reading.

 

 

 

[kickstand80]

Cylinder 3 and 4 exhaust valves are next to each other in the head, this is a design flaw and a good place to look for cracks. Have you had the head checked by a shop for cracks? That may be your only option. 

[Dave WM]

14 hours ago, kickstand80 said:

Cylinder 3 and 4 exhaust valves are next to each other in the head, this is a design flaw and a good place to look for cracks. Have you had the head checked by a shop for cracks? That may be your only option. 

I will pull the head soon, will take a look, see if I can find a shop that can do for me. Thanks!

[Patcon]

Is it possible the water jackets are contaminated now and that is throwing the test?

[Dave WM]

Not sure exactly what it looks for. the puzzling thing is I sorta went thru this with the Non turbo, one day went out and test it again and IIRC i tested ok with the MN47 and then did with no changes made. Never failed since (i have tried it many times to confirm). Its NOT overheating (stayed right at 180-185 max on a super hot day with air temps over 100f, no thermostat mind you but no shroud either and not the best fan placement with respect to the rad.

I will try filling the rad up to the top, then starting and see if water boils out. I think I have seen where if gases are getting in, esp on a cold engine then the water will quickly overflow the filler neck as gas displaces coolant.

Edited August 4, 2022 by Dave WM