changing efi hoses on 78 280z

[Zed Head]

You said that it runs great. Are you just trying to fix the gassy smell from the exhaust now? Where is the timing set, and what is your idle speed when you're measuring intake vacuum. Also, measuring the resistance at Pin 13 of the ECU connector is the best way to see if your coolant temperature circuit is clean. Resistance on this circuit will make things richer. Compare the resistance measured to the temperature vs resistance chart in the FSM, Engine Fuel chapter.

Make sure your valves are adjusted, check the coolant temp sensor circuit, verify fuel pressure including the function of the vacuum hose attached to the regulator (~30 psi fuel pressure at idle. 36 w/o the hose connected), drive it around for a tank or two to loosen things up, then decide if you want to mess with the AFM. You need to get all of the very basic stuff right first.

[no.never]

thanks ZH. well at this point i'm back full circle to my stupid original plan of making a 280 my DD while i fix my 260 then sell, instead of just finishing my 260. curiosity killed the what?, the budget. so if i'ma be driving this i wanna get it solid without too much work or $. i need to pass smog and the smell is telling me it's probably not ready or not right.

i don't know where the timing's set. my idle starts at 8-10 then when it leans out (see i'm learning) it goes up to 15 and doesn't drop. valve adjust is out of my level, maybe i can find a z shop around me that can do that and maybe help out with the smog. looks like i got some tests to do next time off.

[EuroDat]

If you have pulled injectors, you can adjust valve clearance. Just ask for help when you start. There are a couple of pointers to get you on your way.

Projects can get like that$$$$

chas

[no.never]

i remember reading, i think in a link in atlantic z tech, about using a nylon rope. seemed do-able maybe even at my level, with the nicely detailed instructions on that page of course. and here, hehehe. had i thought about that i might've tried it. specially with the cover clear from the rail and waiting for parts. i'm the "whilst i'm here..." type too, there's always next time. would've taken a bit longer but would've leveled up my z level.

[FastWoman]

I agree with EuroDat. Valve clearance is slightly tedious, but otherwise not particularly hard. In fact it's sort of fun in a weird sort of way. If you enjoy paste waxing your lovely car, adjusting valve clearance is the same sort of experience under the hood, albeit not as physically taxing.

I did forget timing. If your timing is off, that could make a big difference in engine performance, and it would show up in your vacuum.

Getting your car to pass California emissions is a big ball of wax with which most people on this list have very little familiarity. You probably need help (probably local help) from a fellow Californian Z enthusiast.

[FastWoman]

i remember reading, i think in a link in atlantic z tech, about using a nylon rope. seemed do-able maybe even at my level, with the nicely detailed instructions on that page of course. and here, hehehe. had i thought about that i might've tried it. specially with the cover clear from the rail and waiting for parts. i'm the "whilst i'm here..." type too, there's always next time. would've taken a bit longer but would've leveled up my z level.

Whoa, there! It sounds like you're talking about removing the head! To adjust the valves, all you have to do is to remove the valve cover -- MUCH, MUCH, MUCH simpler!

[Zed Head]

Yes, FW, there seem to be several ways to go wrong in front of n.n. Eurodat mentioned removing the injectors (maybe he meant something else?) in Post 51 in order to adjust valve lash. And I think that the nylon rope trick is for holding the valves up for changing valve seals. Both way more work than necessary.

In the Engine Tuneup chapter of the FSM, the valve lash adjustment procedure is pretty well-written. It is the first tuneup procedure described. You don't need the fancy tools though. There are several internet procedures out there for adjusting them while hot, but just do it cold first, then check hot if you're worried. The hardest part will be getting the lock nut loose without busting up your knuckles or bending your spray bar. Use a heavy mallet to tap on a wrench instead of trying to muscle it loose.

[no.never]

Whoa, there! It sounds like you're talking about removing the head! To adjust the valves, all you have to do is to remove the valve cover -- MUCH, MUCH, MUCH simpler!

NO NEVER! not even in my dreams would i dream of doing that, i barely wanna take the cover off. even though it would be ok just don't feel comfortable opening the motor, one day. The two responses i get for the z: 1) "i used to have one (several) of these," and, 2) "In-line 6? oh those are easy." so when i thought about doing it to my 260 i researched it and i bought "How To Restore Your Nissan L20" book. i remember reading the valve adjust parts (first couple of chapters) then it just got ridiculously complicated after that, but saw how the L20 looks inside. 260 is a good candidate for that though, has been sitting for almost a year and the manifolds and carbs are off.

Yes, FW, there seem to be several ways to go wrong in front of n.n.

Don't know what that means, but buddy there seem to be several ways to go wrong with me period, hehehe.

This weekend I'll check FSM ET, timing, plugs, continuity, and vacuum. also start looking/asking around for a local help, found two z shops around. one has a full electric 280z in the front page of their WS, the other you can see part of the owner's black pearl in the background of a picture. those seem like good signs.

[no.never]

did find a post from a year ago when you guys helped angriest with a valve adjust, "newb valve adjustment on a 78 280z", hmm the title is where i'm at. very informative. looks like that's where i'm headed, just not as deep into the rabbit hole as angriest. seems like he just wanted to be 110% certain before jumping and needed a push, i'd be that scared too if i had put in as much new parts as he did. yikes. ah but the reward is what makes this game fun!

looks like i'ma be serving up a cold order of valve adjust once the sun is out. i forgot about the ET section, you're right ZH first one up. i guess all i need is a 27mm for the locking nut and some feelers, right? to move the crankshaft to get the lobes up, i do it from the alt? what is this high tension cable from the coil that i have to disconnect? is the lock nut tightened after each turn or after all?

having fun driving. no problems. did have an instance at a light where i saw my rpms drop, which hasn't, to 5 like it was going to 0. when i saw that i thought, uh-oh, then gave it some gas. went back to 15 hasn't happened since. weird.

[Zed Head]

If yours starts at 10-12 and makes its way to 15 when it leans out (in response to rising engine temperature), I'd say you're running too richly

Fastwoman was talking about inches of vacuum here, in Post #47, but in the previous post, #46, it looks like you're reporting RPM. Have you measured intake vacuum yet?

Edited November 29, 2012 by Zed Head

[EuroDat]

Eurodat mentioned removing the injectors (maybe he meant something else?) in Post 51 in order to adjust valve lash. And I think that the nylon rope trick is for holding the valves up for changing valve seals. Both way more work than necessary.

Hi Zed, What I meant. If you have the technical know how to remove injector and track down electrical problems in your efi you should be able to adjust vavle clearance especially with the fsm.

"rope trick" I have never used the rope trick to change valve seals. I have always used the sparkplug fitting from my compression tester and the air compressor to keep the vaves in place. Keeping the piston close to tdc with tranny in 5th and hand brake full on.

Chas

[no.never]

oh i see the mix up, we were talking about vacuum but i was referring to rpm then. sorry about that. vacuum hasn't been measured yet, ill pick up a vacuum and a compression tester.