NismoPick

yep... the farthest in edge of the pulley.... if you can run your finger along the edge, you'll feel the "V". Get some liquid white-out to mark it.

duowing

Ok, we set the timing. When we checked it, the timing was pretty close with the TPS connected, but then we disconnected the TPS and the timing was way off. So we adjusted it with the TPS disconnected, so the timing looks about right. When the TPS is on the timing is off by alot. We took the car for a drive and it was doing a lot better, but not perfect. It still seemed to get some popping up around 60-ish mph which seemed to be around 3250 rpm, once it would hit 3500 rpm the turbo would start to go and the car felt really good. We came back and checked the timing and when we took the TPS off the timing was off again. I may have moved the distributor a little when I tightened the bolts up just a bit more. So we redid the timing. The timing, at least right when I crank the car over seems to bounce somewhat then eventually evens out. I revved it a bit with the TPS connected which seems to have some trouble and a little bit of popping. We have yet to take it for another test drive. I didn't pay attention to the rpms when it started popping so I'll get back to you guys on that. Any suggestions here? I think I'll go check the AFM as well.

EDIT: Ok so we at least triple checked the timing before we went for a second test drive. We revved it some more, checked again, turned it off, on, checked again, etc. We took it out for a drive and just going up the freeway on ramp the car had so much more power easily went to 60 and over and felt really good. I guess when I was finishing up tightening the distributor the first time I must have moved it a bit. Either that or it might have been due to the car not being at normal operating temp, but it seems far better. There does seem to be a slight miss somewhere around 2250-2500rpms, but I figure I'll just mess with spark plugs and wires and that should do the trick. Thanks for all your help guys. I'm glad to be driving my Turbo Z!

duowing

Few last questions. I got all new plugs, and ordered new wires to put on the car. The car still seems to be a bitt odd from a cold startup and the only other noticeable thing is the car at least from a stop and at slow speeds seems to lag around 2000-2500rpms. Is this normal for a turbo car? I know they have lower compression, so I'd imagine the acceleration when the turbo isn't going would be a bit slower, but it still seems like it should be a little better. The car accelerates and everything, just seems to lag a little.

jfairladyz

the car compensates for the lack of compression with more timing. So the difference down low compared to a non turbo is negligable. If the car is having issues while cold the check to make sure the air regulator is operating properly. Mine is starting to take a crap on me...I'm starting to get a slight hesitation down low when the car is still warming up. But once I'm warmed up it's gone. The car should rev freely from idle.

duowing

How can I check if the air regulator is working, is there a specific resistance to check for?

jfairladyz

first off, before you ever start the car, and preferably in the morning while it's still cool out, pull one of the air hoses off of the regulator and with a flash light have a look inside. It should be wide open. If it's not, it's bad and needs to be replaced. Thats how you check for a regulator thats screwing with a cold engine.

If it were affecting the engine while hot (constant fast idle) then there's more to check.

duowing

Do you have any way to test the injectors to see if they're firing fully? For my lower range acceleration basically pre-2500rpm it like I said seems a little slow. If it's just spark would that be enough to cause it to heistate? My guess is that the plugs either need to be replaced or cleaned simply because of the timing being so off that the car was probably running rich that it fouled the plugs to an extent.

duowing

I checked the air regulator like you said, and it doesn't look wide open. It's like there's a little metal piece in the way. It looks as if it's something that would move until the hole is fully open? Ok, my next question is, where can I get a new air regulator from? I've been trying all kinds of different searches on advance auto parts and autozone.com. I cannot locate an air regulator.

tomjohn51

I just put in a new air regulator today. Got it from RockAuto (www.rockauto.com). They call it an Auxiliary Air Valve. Mine was about $75, I got it fast, and it solved my problem. My 1982 Turbo was idling badly and was sluggish when cold, but the problems went away as soon as it warmed up. The new Air Regulator fixed the cold start issues. I also made sure my connectors are clean and I replaced all the air hoses connected to it. Be careful to get the correct one - there are diffenent versions among the years/models of the 280ZX. Hope this helps.

duowing

Well this I think will be my last question. My car at least when I'm accelerating or giving it gas, has like a clicking noise. It kinda sounds like a motorcycle when it's accelerating. Is this just meaning it needs a valve adjustment?

Other than that I've checked compression and all 6 cylinders were about give or take 1-2 psi of 140. We've set the timing, and after new plugs and wires, once the car gets to nromal temperature it seems to run really well. All I need to do is just get a muffler and I'll be good to go.

jfairladyz

your valves are hydraulic on the turbo (only cause you have an 83) and can not be adjusted. Check to make sure the turbo doesn't have a leak. Check around the bolt heads for exhaust gas coming out. A small leak like that will cause a sound that sounds like a clicking or I guess almost a small motorcycle (stewart little ).

If your air regulator was closed, and the engine hadn't warmed up yet, then its bad. It should start out open and then work it's way closed. I've never ordered from Rock Auto, but I know their prices are cheap. Nissan can also get the part but it will cost you more... also, blackdragon automotive and motorsport both carry them. But again,they're not going to be as cheap as Rock Auto.

And make sure you specify that it is for the turbo. as was mentioned above, they're not all the same.

PooFlinginMonke

Exhaust leak....broken stud on rear hole of exhaust manifold.

duowing

Now for the Air Regulator, the cheapest Advance Auto Parts has a Python Auxiliary Air Supply valve for $58.99. Now I don't know if that's a good brand to go with, or if I should just bite the bullet and get the part from rockauto?

As for the exhaust noise. I've not worked with the exhaust on this car, but how big of a job could that be if the exhaust manifold needs to be replaced?

jfairladyz

well if it works then it works. Although, there is no telling how long it will last. Is there a warranty on it???

As far as the exhaust manifold goes, it's not a fun job the first time you do it. It's not too difficult, but can be time consuming for a first timer. Verify where the leak is coming from first. I had the same issue on both of my Z's. Twice on my NA and once on my turbo already. On the na I had a warped flange where the ehaust manifold bolted to the down pipe. It also developed a leak at the exhaust flange to head surface when a nut went missing off the end stud. On my turbo there was exhaust leaking past one of the wastegate housing bolts. A little exhaust sealer took care of that one.

duowing

Yeah I'll go about trying to figure out where the leak is. What's the best way to go about finding that? I'm thinking seafoam would be a pretty good way since it all comes out as white smoke, so I'd definitely see it.

As for the regulator I just decided to go ahead and get the Bosch regulator from rockauto. Only $15 more and I don't have to worry about brining back the old part.

duowing

It looks like my exhaust leak leaks a bit in two spots where it attatches to the head. I'm guessing it's the gasket. I was using seafoam and some smoke was coming from around the back and the front of the exhaust manifold. I can't tell if it's the gasket or something is broken. I'll have to look into it. How can you tell if it's the gasket or like a broken stud? My other question would be in the case of a broken stud or bolt, how big of a pain does that become to fix? Or how easy is it to get ahold of new studs.

jfairladyz

I wont get into the detail of stud removal, it's been covered many times on this forum...and I'm sure somebody else will get to it. But as far as the gasket or headstud problem goes: Just get a new gasket. Either way the gasket is bound to be bad. If there is a leak due to a loose or missing stud/bolt then chances are the gasket has since burnt itself into uselessness (is that a work ).

Lets just hope you're lucky enough to have just a leaky gasket or a loose fastener. I've had fasteners come loose on me plenty of times causing a temporary exhaust leak. If thats the case, just try tightening everything up to see if that fixes the leak before attempting to take anything apart.

duowing

One more question I had involves the studs and bolts. What is it that can cause a stud to break off if the exhaust manifold if it's never been removed.

PooFlinginMonke

They break because the head and manifold expand a quite a different rate.

This means the studs on each end get side loads far too often.

duowing

Sorry about this really crappy picture, but I was looking at my Turbo. And this is around the area where at least part of the leak is. This is from my 2+2 by the way, but there's like a little open ended piece of metal that looks like it's the exhaust manifold attached to the head. There isn't anything sticking out of it, and there isn't a nut. I look in there and it looks like maybe a stud, but like there's no way to get at it? It looks the same on both my Turbo and my Non-Turbo. Is this correct? Also I know the Haynes says there are 8 bolts and 2 nuts attatching the manifold to the head. Are the other bolts not visible from the top? If anyone could give me locations that'd be appreciated.

jfairladyz

all the bolts are located under the intake manifold. Some are shared by both the intake and exhaust manifolds. If you remove the little access plate on the top of the intake manifold you'll have access to one of the exhaust manifold bolts and be able to see 2 more. Both the turbo and non turbo exhaust manifolds bolt to the head in the exact same way. The two studs are at either end of the exhaust manifold.

and uh...that must be a really crappy picture cause I dont see a picture at all

duowing

But the studs are visible and above that plate? Oh and I updated the picture. I'll see if I can find a camera to get a better one.
Here's some pictures of what I'm talking about, they're kind of crappy, the camera isn't great, and there wasn't much light. Like I said I can't get at a good angle to tell, but I would think this is where a stud or something would be. There appears to be nothing sticking out as I can stick my finger in there and I don't feel anything sticking out. Like I said this is the same on both cars. One of the bolts, maybe some more felt kinda loose towards the front of the head. I'm just really hoping I don't have a broken bolt or stud. If so I think that might be the only thing I take this car to a shop for. I'm really not the type to start dealing with drilling broken studs or bolts. Oh and even having a slight exhaust leak. Is that something that would effect performance or anything? Or would this just more than likely be something that's just there and annoying to know I have it?

And here's a pic of my Turbo Z(my brother took this one).


EDIT: Well I was searching and found thxone's post about his exhaust manifold. Looks like what I've been looking at is the famous rear broken stud. I'll have to ask the mechanic that we know for help with that one.