duowing

For me it's always a learning process that ends up taking me a looong time the first time I do it, then once I know what I'm doing the next time I bet I could do this in just a few hours. Also being from Cleveland, Ohio certainly doesn't help for exhaust related parts under the car because they're all old and rusted together. So far I'm learning it's not all that hard to do, it's just getting to know where everything is, and then getting the old things apart without breaking. Mainly I just need my stock exhaust with the cat so I can get it through emissions, after that I'm dumping it all.

duowing

I was wondering if anyone had any suggestions. Should I use any kind of sealant when putting the intake/exhaust manifold gasket on?

snwbrderphat540

a new gasket should be just fine.

tickwon

I didn't put any sealant on mine either.

duowing

I have a quick question. I need two of those washers that go on the bolts/studs that mount the intake and exhaust manifolds to the head. Those real thick heavy duty washers, does anyone know what part number that is so I can order them through Nissan, or does anyone know what else I can use?

snwbrderphat540

ummmm, they are washers... just go buy some.

tickwon

Yeah I have no idea where you would get washers that thick. What I would do if I was in your situation would be to find some washer (as thick as possible) and stack them. That's what I would do if I ever lost one of those because I was thinking about that one day...what if I lost of of these things? Just try to find the thickest washer possible and stack them. That's my best suggestion.

snwbrderphat540

i really dont thin kyou need that stupid thick of washers anyways.... thats if we are thinking of teh same washers....

jfairladyz

^ no, you probably do. Think about how hot that exhaust manifold gets and its those washers that hold it to the head. Sure maybe they are overkill as thick as they are, but I wouldnt chance using too thin of a washer that will distort and end up causing a leak when it cant keep the manifolds sealed to the head. Stacking washers would be my best suggestion as well if you couldnt source something that thick.

duowing

I found some washers that came off my old 300ZX, I can use about 3 of them to equal the thickness and size of the 280ZX washers. I figure what I'll do is use them for the ends that just hold the manifold to the head, and use the the other 6 I have for the studs that share the intake/exhaust manifolds.

ZYAL8R

Yeah, you can stack some 3/8" washers. I did it on the far left bolt. Just make sure you tighten the bolts a little at a time, as much of a bitch that it is, it gives you a good seal.

duowing

Does anyone know what kind of symptoms a stuck PCV valve would cause? I finally went to replace my old one, I saw it on the intake and thought, Oh yeah, I have a brand new PCV valve. Anyway the old one was pretty much stuck, after messing with it, it kind of rattles like the new one, only it keeps getting stuck and what not. I'm just curious as to what issues that could cause.

duowing

Alright, got everything back together. Well so far it seems like no different, I don't know if the fact that I kind of scraped parts of the gasket when putting the intake back in would cause a problem? I was trying to spray brake parts cleaner around the intake to see if the idle jumped, but I didn't notice anything. I'm gonna check more tomorrow to at least see if I eliminated my exhaust leak.

Anyway my car I'm not sure if it almost overheated or what. I noticed some smoke coming from the hood and the smell of coolant. So I pulled over and the engine bay seemed really hot, overflow bottle level hadn't lowered. Anyway we sat for a few minutes, and then started going again and I got it back home real quick and basically turned the car off as quick as I could. I saw that I had messed up the connectors for the temp gauge with another connector. I'm not sure if that would cause problems with running? Anyway the smoke stopped. I think it was only from the coolant I had spilled when filling the radiator, and the overflow bottle level had lowered. So I'm wondering if my thermostat just got stuck or something? I know these temp gauges aren't the best, but I reconnected it correctly, and my temp level was showing normal. I hope nothing is ruined.

Anyway my main problem is, the car runs pretty crappy when it's cold. Once it warms up the car runs fine. I can't seem to eliminate this problem. My last thoughts are maybe I need to buy a new CHTS? Here's everything I've done so far:

New/Remanned Parts
----------------------------
- Battery
- Battery Clips
- AFM
- Air Regulator
- O2 Sensor
- Injectors
- Fuel Pressure Regulator
- Ignition Control Unit
- Ignition Coil
- Distributor
- Distributor Cap
- Distributor Rotor
- Spark Plug/Coil Wires
- Spark Plugs
- Intake/Exhaust Gasket
- Turbo Downpipe Gasket
- Turbo Inlet/Outlet Gasket
- Thermostat Housing Gasket
- Various Vacuum Lines
- Hatchback Lift Supports

Swapped From 83' 280ZX 2+2
----------------------------
- TPS
- CHTS

Other
----------------------------
- Reset Ignition Timing with TPS connected
- Re-calibrated TPS with feeler gauge
- Plugged off EGR System
- Flushed Cooling System

Edit: One thing I forgot, after I had stopped in the parking lot, the car might have set maybe 10 minutes if that. Anyway I started driving the car again and getting on the freeway for just a moment or two, I had the popping/sputtering while accelerating that I only seem to get when the car is cold. It then quickly went away and the car drove fine again. Someone suggested the Crank Angle Sensor possibly causing this? I'm just beginning to lead more towards the CHTS because the first time I swapped it over, it drove fine in the morning, then bad in the afternoon. The car then sat for a couple of days, I put my new AFM in. It ran really good that day from cold, it cooled down and then the next morning starting from cold it ran like crap again, and has since then.

Update: Ok I was outside messing with it, I was spraying carb cleaner everywhere under the hood pretty much and I wasn't finding the car's idle jumping or anything. I took the oil filler cap off and then the idle dropped, the car wasn't sputtering, and the idle didn't drop alot, but it was enough to notice a difference, and then I put the cap back on and then you'd hear the engine speed raise, so I don't know if I could still have a vacuum leak, or if maybe it's just related to a sensor? I went through and waited for the car to stop fast idling some, pulled off the filler cap and then the thing really started sputtering, and running bad. Soon as the cap went back on, the car ran much better.

duowing

Well, I came to a thought about my CHTS. I was thinking about how when I first swapped it, the car ran really good from a cold start with little to no issues. Then after sitting, and then the AFM swap it ran really good from a cold start two times in a row, then afterwards just never did again.

Well I started thinking is it possible the CHTS can develop a range that it works fine in and work crappy outside of that range? For example it runs crappy when cold, then it gets to the temp it works good at, then how the engine got hotter than normal, it started having the problem until the engine got the coolant flow going and went back to normal temperature and ran fine again. Does this seem possible?

BigEkak1941

If you broke one of the heat shield bolts it's no big deal, but if you break any of the exhaust manafold bolds (which I did) I found it easier to just pull the engine as it's so much easier working when using an engine stand allowing you to get to all the bolts so easily. It's next to impossible to drill out bolts with the engine in the car. Use the PB blaster as previously mentioned (use it for several days to allow it to soak in) don't be in a hurry and you shouldn't break the bolts. Good Luck

duowing

Alright, quick question, I know this thread is old, but I figured since this was on the topic of it, I'll just continue.

Anyway I think the source of my vacuum leaks are at the manifold gasket, I may need to redo my intake gasket, now my question is, am I able to just kind of cut up the intake/exhaust gasket, only pull the intake and re-gasket the intake manifold, or do I have to pull the exhaust manifold as well?

NismoPick

The intake & exhaust share the same gasket. You'll need to pull both manifolds.

duowing

That's what I figured....I knew that they shared the gasket, but I was hoping maybe I could trim the whole gasket and maybe just do the intake part, but oh well.

I'll try checking the torque on my bolts, and make sure I need to change the gasket before I pull it all out, although it should go quick. I found a really neat guide online to finding vacuum leaks by using the O2 sensor.

snwbrderphat540

unless you slid teh manifold around alot when you were putting it on, i doubt you need a new gasket. the exhaust gasket would go out before the intake. you used all the bolts right? i skiped on bolt and blew my exhaust gasket

duowing

Yeah I used all the bolts, but I did end up moving the intake manifold around a bit before I got it seated, I remember looking at the gasket and found that it had gotten scraped up and stuff, so I don't know if it was enough to cause the gasket to leak or not, I don't notice a difference in engine sound when spraying brake cleaner or anything around it, but if I run a piece of vacuum hose in my ear around there I can hear air at different points, like I said I'm gonna go through and try to test real carefully.

The reason I did it the first time was because my exhaust manifold was leaking real bad and had the good ol' broken stud, but I got that all fixed. Oh well if I do have to do it, it shouldn't take long seeing as I know the location of all the bolts, I don't have the heat shield on the exhaust manifold, the practically seized EGR tube connecting the intake and exhaust, the rear exhaust stud fixed, and new studs and nuts connecting the turbo downpipe to the rest of the exhaust, so everything should come apart alot easier. I know pulling the exhaust manifold isn't much worse with the intake off, it's just another thing to scrape down. I also got ahold of one of the rarer type intake/manifold gaskets that has the metal or steel backing around the exhaust ports which is supposed to seal better and last longer, but it has the round exhaust ports, I don't know if that will cause a problem with the rectangular turbo exhaust ports?