project 76 280z(s)

[Syncro]

I personally like to "Lucas" or "Marvel Mystery Oil" for top cylinder lube = works well ... I notice a difference

lucas ftw!

[Syncro]

well little bit of an emergency came up and I had to get the car back together in a hurry so all the efi crap went back on temporarily. Tried to start it, ran like crap, knocked on the tank, empty. FIlled her up with some fresh gas and runs way better then before, like it should, its a temporary DD for a week or two, then I'll probably toss the holley on there.

[Syncro]

You know you can change the name of the build, right?

Its named accordingly, if it were slammed, riced, or otherwise, the title would say so.

[Syncro]

well unfortunately I made the mistake of selling the holley 4 barrel setup, but whatever moneys money. the cars registered but I'm having some trouble now, the car is doing the same thing it used to with the fuel pump cutting out from time to time now but worse, its not the pump thats for sure, I've got 3 different good pumps and it happens with all of them. Now though when I'm driving the car when the pump starts cutting out the car will die and it will fire up but the pump cuts out sooner and the car won't pull with out stalling. really stumped on this one, I'd like to trace down where the wires that go to the fuel pump lead too, I'm thinking there's a good chance I'll find the culprit if I knew where those lead to, anyone got any idea's? I could test the fuel pressure but with the pump cutting out all the time I doubt its an issue with fuel pressure, nothing has really been done to the fuel system other then used low mileage known good injectors from a na 280zx and replacing the fuel filter, fuel comes out clean, not rusty and the gas is new.

[Syncro]

fuq it I'm switching to sidedrafts.

[I'm BLUE]

well unfortunately I made the mistake of selling the holley 4 barrel setup, but whatever moneys money. the cars registered but I'm having some trouble now, the car is doing the same thing it used to with the fuel pump cutting out from time to time now but worse, its not the pump thats for sure, I've got 3 different good pumps and it happens with all of them. Now though when I'm driving the car when the pump starts cutting out the car will die and it will fire up but the pump cuts out sooner and the car won't pull with out stalling. really stumped on this one, I'd like to trace down where the wires that go to the fuel pump lead too, I'm thinking there's a good chance I'll find the culprit if I knew where those lead to, anyone got any idea's? I could test the fuel pressure but with the pump cutting out all the time I doubt its an issue with fuel pressure, nothing has really been done to the fuel system other then used low mileage known good injectors from a na 280zx and replacing the fuel filter, fuel comes out clean, not rusty and the gas is new.

 

I would strongly advise testing your fuel pump relay and ignition module connectivity as well as the units themselves

 

Remember your fuel pump (+) is fed off the fuel pump relay.

 

Inspect closely ALL ign related wires in engine bay. Inspect pickup in distributor (if applicable)

 

You can test all this via FSM with a $10 multi meter ..or...

 

I bet if You literally run a fused protected (+) power wire directly to the pump ( controlled by a toggle switch ) and the ground wire (-) to the chasis or wherever. If your issue is solved than you likely have a fuel relay or fuel relay to fuel pump wiring issue. If issue is not solved I would look hard at the ignition module and wiring to it itself. Including the EFI Relay.

 

All of this ^^^ can be tested with a multi meter via FSM SPECS available from xenon.com

 

My guess says ign related BUT ... Testing to FSM Specs eliminates guessing ;)

 

Take but hopefully no more than 1 hour to look up the specs/test the components and wiring.

Thqt would be less time than it would be to switch over to Carbs/buy tools/sync/tune ... Than hqve leaky throttle shafts to deal with grrrrrrr ....

 

Good luck.

[Syncro]

to late, deed is done, the intake manifold is off, and I seek not to put it back on, I've got a tool for carb syncing, plus these carbs appear to of been rebuilt, they are roundtops, not flat tops.

[Syncro]

also I have multiple fuel relays, all of which I've tested on other cars and know are good, I've got 3 different good ecu's that I've tried on it with no change in performance, I have done what you said about hot wiring the pump to the battery and grounding it to the chassis, no change, I'm just so tired of testing and trying, the way I see it the carbs are only gonna get worse the longer they sit, I may swap to triples later, but the fuel injection is just kicking me in the nuts everytime I try to work with it, thanks for the help though, you seem to be one of the only people I've talked to on this site that helps out so much.

[I'm BLUE]

also I have multiple fuel relays, all of which I've tested on other cars and know are good, I've got 3 different good ecu's that I've tried on it with no change in performance, I have done what you said about hot wiring the pump to the battery and grounding it to the chassis, no change, I'm just so tired of testing and trying, the way I see it the carbs are only gonna get worse the longer they sit, I may swap to triples later, but the fuel injection is just kicking me in the nuts everytime I try to work with it, thanks for the help though, you seem to be one of the only people I've talked to on this site that helps out so much.

 

Yup yup. No problem man .. hey at least you tried to work with the system !

 

Ya roundtop Su's or Tripple webbers is a great way to go !

*** Round Top SU's ***

*SU's require choke cables for cold start since there is no accelerator pump in the design (as you know)

*Carefully check throttle shaft play ... If a lot you probably have a leak in the bushing area and will forever give you headaches when trying to tune lol. Don't worry There are cheap temp solutions and permanent professional services as well

*I have personally noticed quite a few worn mixture needles .. just a thought more than anything.

*run the correct dampening oil (hybridz has many suggestions).

* The piston domes get dirty a bit often ... Don't be afraid to clean them ... And make sure they do not stick !

* float level ow pretty vital.

*For an L28 (depending on what you are doing with engine/head/cam) you may need to switch out needles. They are available.

 

I love Tripples for the throttle response ... Muahahahah ... Plus they look cool ... :lol:

*** Tripples ***

*adapt or make hard line/roller ball type linkage ... You can thank me later :) . (Better than cable imho)

*super easy to re-jet ...

*make sure they are super clean before use lol ... Or problems ensue Haha.

*All kinds of partake still available !!!

*Run the Chokes/Air Horns ... some people do not apparently.

*The carter electric fuel pump is the way to feed these ( in my opinion ). I have tried 2 other fuel pumps (under $100 cheapos) and they never worked correctly even regulated ... cheap fuel pressure regulators don't work lol. It's also never fun to receive a fuel pump ... Believe it works within stated specs ... Just to find out it does not lol. Maybe some fuel preasure regulators work but you will have to spend $$ to find out lol. I finally broke down and bought the carter electric pump and the tripples loved me ever since.

*The sound out the exhaust is un-parrelleled compared to other carb systems :cool: ... So make sure your exhaust is killer Haha ;)

*40dcoe's are *probably* just big enough for a DD L28 roundtop or flattop stocker engine that is not pushed. If you are planning on racing or a big cam + headwork + exhaust + diaplacement engine .... I would look into some 45dcoe's or even possibbly some 50dcoe's if you are going to a knarly mad max setup lol. I state this since I have no idea where or what setup you will end up with in the next 5 years. More a matter of opinion than fact on this :)

* Brother used an ultra-sonic to clean some of his smaller finer parts on his Carbs. Just a thought :). I have never done it.

 

Had Tripple 40dcoe's on my L24 ... ran just a touch rich ... Advanced the timing as far as it would permit without giving issues ... Holy shit they made my 240z an ENTIRELY different car ... :lol: :cool: .... I even got naughty and turned the air bleeds out a bit ... Muahahaha ... Trolling up hills like no other lol.

 

Quite literally the 40dcoe's on my stocker L24 were so fun ... I no longer would pine or think about an engine swap ... Even though these cars are hella fun stock/tuned correctly :) . ( just my opinion/experience ). My opinion of tripples on it before and after were completely different. This was with 3.36 diff gears ... Stock 4spd (with a 3.321 1st gear ... (Lower gear of the batch)

 

^^^ after having that setup ... It completely changed my perception of *taller* gearing and transmission ratio combinations. I also broke a few parts after Haha :lol: but are all fixed.

 

Oh yeah I'm sure as hell not stating tripples or Su's are better. Hybridz would have a hay day lol . I still consider myself quite a noob to Carbs in general even though I have swapped out quote a few parts Haha. Just my experience. People are doing some high HP numbers with some slightly worked SU's though ! I have only worked/tuned/rebuilt stock round top Su's They are the lawnmower Carbs of the induatry lol. Too easy ... Great carb when in specs !

 

The sound of SU's out the exhaust is very cool ( granted many factors as we all know ).

 

Oh yeah ... Carb return springs .. use the lightest one you can ... Too heavy and you risk bending a throttle shaft or ? Too light Nd obviously it does not work ! I prefer the old stock SU return springs to new ones ... Just a thought.

 

A lot of this is my experience and some simply stated opinion :) . My knowledge of carbs is ever growing.

 

Good luck man ! Rooting for ya and watching this thread progress. :)

[I'm BLUE]

Also I forgot to mention in my novel above ^^^ lol .check the Su floats carefully ... For sunk or partially sunk ..

 

*** IMPORTANT make sure your dizzy is in good specs. ***

--- carb is not worth tuning or re-jetting unless the distributpr is in good shape !!!

 

---hybridz.org has some good info and views on distributor and tripple dcoe setups :)

 

---when I ran tripples I simply just simply advanced the timing on a good EI zx distributor (e12-80 module) and hoped for the best. I guess you could recurve it and re-furbish it ... But recurving takes a lot of time ... Have to know cam specs I believe and have the machine to recurve it correctly. I do not know anyone that knows how to do it correctly other than trial and error lol.

 

---Another option is a Mallory Uni-lite distributor with an adjustable mechanical advance. Combined with some real 8mm plug wires and a hot coil = moar better. This is simply my experience and opinion. There is soooo many combo's with these Carbs I wouldn't't ever get the chance to test many of them Haha. Mallory actually supplies and still sells weight and spring kits , so you can easily *attempt* to switch out parts for recurving yourself. The down side to these dizzys is uniqueness ... and the modules/pickup will burn out faster than the Nissans by far. Replacements are $31-$52 a piece. Not too bad ... Jist carry a spare :)

 

A local company might be willing to repair your distributor for around $100-$200 ish !? A Mallory Uni-lite would be just a bit more with more features and tuneability. I switched out quite a few distributors and have found a couple that "work good enough" but def not a long term solution lol.

 

Just remeber this ... If you think you're chasing a carb issue ... Look at your ignition/distributor closely at that moment ;)

 

I "kick the dead horse" a lot on the distributor issue because I believe it is over looked or qualified as "good enough" in some cases (which I have to do myself as well Haha )

 

I honestly think you will be happier with carbs.

[Syncro]

so what do I do about the holes for the injectors? plug them up I'm guessing, but do I simply use normal bolts or is there something special I have to do?

[datsunaholic]

Holes for the injectors? If you go carbs, you also need a matching carb manifold... which won't have holes for injectors.

[Syncro]

Holes for the injectors? If you go carbs, you also need a matching carb manifold... which won't have holes for injectors.

the n42 head has a hole for each injector on the side of it, the holes are threaded but I can't find the right size bolt for it, the carbs were pulled of an e88 motor and the manifolds say have a spot on it machined that says e88.

[Syncro]

I now have the carbs bolted on and the fuel lines hooked up, which is great, though I'd love to find a couple of photos of some su's in other cars so I know where to hook up a couple of these hoses and lines. Still need to get a pump, what psi should the pump run at? I'm guessing something like 5-7 psi.

[datsunaholic]

The threaded holes you're talking about are the bolt holes for the EFI manifold. You don't do anything with them. The injectors don't go in the holes, they go in the manifold though there are small notches at the top of each intake port for the injector nozzle.

[Syncro]

see what you mean now, yeah, I only saw six holes though and when I looked at how the injectors were positioned it looked like I was going to have a problem, thanks for that.

[I'm BLUE]

yeah dont even blink on injector holes ,,,

they will not interfere or cause problems in any shape or form

You may have to go to the hardware store or junkyard for the smaller SU manifold bolts.

 

Don't torque the living shit out of your manifold bolts ,,, I made that mistake at 15-16 years old = leaks lol.

12-15ft lbs I believe-ish ? ( don't take that for absolute fact but it is damn close ! )

 

hmmmm Fuel pressure at 5-7psi is about adequete ,,, I wouldn't go above 10psi if can help lol

I think I was running mine at 6psi without problems. I did have a shitty little cheapo electric fuel pump I installed that promised 8psi max ,,, it shot up to 18-ish and the return line was clear lol ,,,kicked it to the curb.

I am no SU expert.

Hybridz is the place

 

EDIT : ^^^ come to think of it ,,I never did look up what the proper fuel pressure was for the SU's since I did not have trouble at the lower pressure pump.

I will have to look that up soon !!

 

I bet 72240z knows what the fuel pressure should be. Damn SU guru :lol: ;)

[Syncro]

anyone know what all has to be removed to use the carbs, I've got a 5 psi pump, but the fuel isn't getting to the carbs, I've already removed the dampener, I'm assuming there are quiet a few stock parts for the injectors thats keeping fuel from flowing past it?

[Syncro]

Alright well I've decided to try out the mechanical pump tht was on my 240z, alright have it on there and bolted down, just need to remove that electric pump, the pump that was on the 240z was an old moroso pump, hopefully it works, I blew some air through it just to make sure it wasn't clogged, there are 2 things I'm a bit concerned about, there is a line that comes from the tranny that used to go to the old intake, but there's no spot for it on this manifold, I'm assuming this line is the equivalent of a kickdown cable. Any idea's on what to do with it? also, there's this thing that has 3 hoses coming out of it on the manifold, 1 line goes to thew fuel rail, the next goes to the exhaust, and then there's one more hoses that doesn't appear to go anywhere, any idea's?

[Syncro]

figured it all out, aside from that one fuel rail exhaust hose deal, still haven't figured that out, but I do believe I know what the problem with my injectors were, because I'm having the same problem now, except it gets it bit worse, its the fuel tank, the vent hole on the fuel tank that goes to reserve tank I guess you'd called it inside the car, it was clogged, as well as the a bit of rust and sludge build up inside my fuel tank, but the vent hole is more then likely the issue as well as the sludge, I'm gonna get the tank as clean as I can, blow out all my lines, and see what happens, I may switch back to the fuel injection just to see what happens, but for now I'm happy with the carbs.

[Syncro]

Damn (insert explicit term hear) tank, Well I do believe it shot, or close to it, 2 holes formed in the bottom of it, cleaned it out with some heavy duty acid today before the holes started, the acid really did its job, stuff that came out looked like chocolate milk, mmmm. anyway, its still clogging up the lines, and the tank has those 2 holes now, I'm pulling it off tomorrow and cutting her open, I'll just put it back together with fiberglass and patch up though holes temporarily til I make another fuel tank. For now I'm driving my brothers old 83 RX7, its got a 12a but it pulls damn good, all stock too, maybe I should start a thread in the off topic for all my cars like my camaro and rx7, if I can get this z drivable I'll finally be able to start working on my eclipse again (woot!).

[I'm BLUE]

that sucks lol . I was kinda wondering if that was the case. At least ya found it !!

 

I don't know about cutting it open and laying fiberglass back over to seal (I literally have never done it ).

 

,,, if you have money take it to a radiator shop and have them boil/dip/seal it ,,, that is ,,, if they are willing to do it after an inspection :lol: ;)

 

Love 83 rx7 !!! had an 81 !!!!

 

sounds like you are on your way !

[Syncro]

I've worked with fiberglass quite a bit (points to eclipse), so I'm sure I can get it to work, my concern was that the gas woudl eat away at the fiberglass but my dad assured me it wouldn't. Yeah I was actually all set to pay for half an 84 gsl se rx7 before the 280z, me and my brother had a deal worked out where he got what he wanted from it I could the remaining corpse and parts from his rx7 he wouldn't need, he mostly wanted the diff. Turns out my brothers more then a dick then I thought and a hell of a lot less loyal, bastard when up there the day before me and him were supposed to and he bought it. that jackass went back on everything, so out of anger I bought this 280z, when I got it it needed 2 things to run. he hasn't taken any of the parts he wanted from his 84 yet. His 84 still needs the motor and tranny put in it as well. He fell quite far from where he once stood, admired him up until he sudo abandoned everything but his girlfriend. really wish he'd come down, could have that 84 running around in a weekend, well enough of my bantering.

[I'm BLUE]

Cool ! Would love to see the pics of the inside and the fiberglass over the tank !

 

I was more curious of whether the fiberglass was going to flex/crack overtime ? ( I really don't know )

 

 

Yeah ,,, well ,,, sounds like your brother needs some time to grow up ,,, girls def have an effect on a dudes life lol.

Give it time and patience... family's important.

 

oh yeah ! sorry bout that ,,, I do remember you have the eclipse with the fiberglass work !

 

Congrats on the finding the problem !

[Syncro]

well my brother thinks acting his age is putting up with some despite how bitchy they are, that being his girlfriend, he's 5 years older then me but how much of a wimp he is disappoints me, and he wasn't always like that either. Well I'm going to lay gelcoat over the fiberglass, gelcoat is like bondo but a millions times better, so it should work out fine, hopefully. Yeah took some time but tracked her down, maybe I can answer the millions who've asked the same question all over the internet, can't tell you how many of those I found and had no answers or answers so far from what it was it was ridiculous.