Chickenman

That method of operation is incorrect. An inline electric fuel pump must be operating when plumbed in series with another fuel pump ( Mechanical or electrical ) . Shutting off an inline pump creates a lot of fuel flow resistance.

I can see the problem with the IAC. That's pretty danged close to the exhaust pipe. If you have the room, a 1/2" or taller phenolic spacer under the TB will certainly help matters.

Personally, I'd stay with the 180 F thermostat. I believe it was Braap or Blue that found that the coolant temp between #5 and #6 runs about 20 F higher than what is measured at the Thermostat housing. N42 and N47 heads are quite prone to detonation in their stock forms and running higher coolant temps ( over 180 F ) does not help with mileage or performance. None of the hard core 510 or Z guys run higher than a 180 F out here in BC ( that I know of ). Dyno testing have supposedly shown HP loss with 195 vs 180 thermostats. These are on some pretty serious 2.1 and 2.3 liter L series 4 bangers. with 160 to 170 rwhp ( Normally aspirated ) out here. Specialty Engineering motors. Some of the the Turbo 4 bangers are running 250 to 275 rwhp If you engine temp is 150F in 50 F ambient, it sounds like your thermostat is not operating correctly. I have a Nissan 180 stat,, three core copper rad and my car runs a rock steady 180F if it is 50F or 100 F ambient. Some of the aftermarket stats ( including Stant ) fluctuate much more than the factory units. Been that way since everything went " Global ". Quality just isn't what it used to be.... AFR's look good for a baseline starting point. Assuming engine is stock. A bigger cammed engine will want more fuel at idle. But that's SOP.

I've seen a few of these EFI 4BBL conversions, and they've all benefited from a large heat shield mounted directly under the TB to reflect the header heat downwards. You can run into a fuel peculation issue similar to a Holley carburator. A sandwich style plate of Stainless steel with insulating foil on the bottom side works well. I would also add a thin phenolic spacer under the EFI TB. Anything to isolate the TB from heat will be a benefit. If you drive the car in Winter, you want the manifold itself to get heated, but not the carburator or Throttle body. Summer in Ontario? Not so much. The TB actually do have issues with heat soak, although not as a bad as carb with float bowls. There are still passages and chambers with fuel in them that can boil on an EFI TB. Regarding the wiring on top of the coil. I would think a minimum of 3 inches would be OK, although I would prefer at least 6 inches from the coil. Big EMI around coil. Depends what those wires are for. Sensor wires are sensitive to EMI , and Trigger wires for Ignition are very sensitive. to EMI

Bingo!!

Very nice. One suggestion. Move that electrical terminal block off the Ignition coil and route the wiring further away from the coil. Ignition coils produce a lot of EMI and can create induction voltages in closely run wires. If any of those wires are the trigger wires from the dizzy or any EFI sensor wires it is particularly bad.

^ I know where this is going.....

Ah... now that tells us a lot. Definitely sounds more like fuel supply issue now. That plus the half full fuel filter is pointing towards fuel. You mentioned in your first post that you have both an electrical and a mechanical fuel pump. What brand and model is the electric pump? Where is it mounted ( Puller or pusher ) Check for pinched lines or kinked lines. As I understand, you haven't checked the float level on the SU's yet? That step should have been one of the first things you did. Also check the Needle and Seats for any obstruction. You should be installing a fuel pressure gauge on the car and monitor in real time. You can temporarily mount one outside the car using a long hose and secure it outside the windscreen. That will eliminate a lot of the fuel variables. Fuel volume issues will be worse under sustained high loads ( 3rd and 4th gears ) up long hills. Car will often rip through 1st and 2nd, then start bucking under longer loads due to lack of fuel volume and pressure. Unfortunately a weak ignition system can cause the same problems. BTW, you say you removed the MSD and replaced it with something else. But did you check the spark quality first? That is important and you haven't answered that question yet ( that I can see ) . You could have something like a coil HT lead that has gone bad. Check spark at both coil lead end and spark plug lead ends. You have to eliminate things one by one by testing operation of systems as a whole. Otherwise you can chase your tail for a long time. Not to get off track. But what brand and type of plug leads? Just curious.

No, that doesn't sound normal.

Have you checked the spark quality yet? MSD 6 boxes are known to fail in lots of weird and wonderful ways. They don'y always fail completely. Pull the HT lead out of the dizzy and hold it a good 1/2" away from a ground point. Have a helper crank the engine while observing spark. A healthy MSD Ignition will easily jump a 1/2" gap and should give a sharp white/blue spark with a distinctive " Snap " sound. Any weak or yellowish spark is a sign of failure. Check it when the engine is cold and also when it's hot. Electronics often fail when thye get hot, but may work fine when they are cold. A weak spark will manifest itself more under higher loads. They have enough juice to fire engine at idle, but fail to properly ignite fuel mixture under load

I think you're missing one or two of the shims in this diagram. Illustration number 22160. Part number for 1982 - 1983 Turbo shim kit is 22160-P9000 . Illustration below is for 1981 Turbo Dizzy.1982 -1983 Dizzy has these two shims, but I could not find an appropriate illustration. 1981 shim kit is 22160-M5600. bad news, both shim kits are NLA. You can scrounge used Datsun dizzy's for these. The shaft diameters are often the same.

Not a whole lot to it. Sure you didn't forget a shim or two? . I just looked at my BNIB unit and it looks like there is a shim between the lower shaft collar ( that engages the oil pump spindle ) and the dizzy body. There is absolutely no free play on my dizzy shaft..... well maybe a couple of thou" . No way trigger disc should hit Optical sensor

1986 to 1988 Supra NA injectors ( 23250-70040 ) will support 250 HP no problem at 85% duty cycle using RC's calculator ( .60 bsfc ) . That's what I'm using on my NA build. These fit the stock 280Z manifold and use the same seals as the Nissan injectors. 11 mm fuel rail O-rings to fit Pallnet fuel rail. Very common injector. If you decide to go with more HP... you can use the 1986 - 1988 Supar Turbo injectors. ( I'll look the number up in a bit ). Of course you need a diffent ECU to tune for these. MegaSquirt seems to be a popular and proven system at a reasonable price. Here are the 310cc Supra Reman injectors listed from Injectorman. $149.95 for a set of six. http://www.ebay.ca/itm/291075192985?euid=2625c1e8b246491face30713a32fdbbd&bu=43214541557&cp=1&sojTags=bu=bu

Never Mickey mouse something on a fuel system. That's just a disaster waiting to happen. Just order a Pallnet fuel rail. Peter is a Hybriz Z member, is on the Vendors Forum and makes quality parts. He can custom make mounts to fit your manifold. You can get them with 11mm O-Ring seals, 14 mm O-Ring seals or barbed fittings on the rail side. Barbed injectors are a PITA if you have to remove them for servicing, changing size etc. IMHO, it's best to decide what you want to run for injectors first. Then have the Manifold and Fuel rail machined for that size. Just an FYI, the factory barbed injectors use a 28 mm O.D. square cut seal around the injector body ( on the Intake manifold side ) and a 14 mm square cut seal on the pintle tip. You can use a 14mm double O-ring on the tip as others have mentioned. I just measured some BNIB seals that I have in stock. Link to Pallnet : http://forums.hybridz.org/topic/99098-pallnet-fuel-rails/

^ Yes, very good point. I just got off the phone with Byron Mestin from " The510Realm ". He's one of our local fabricators and mentioned the same issues. You'll get binding in the suspension on most cars with a Tension Rod located LCA. GM's use a two pivot location method on their LCA's, so it doesn't have that issue. Was just going to post up that it was a bad idea, but you beat me to it. BNIB Beck Arnley front LCA bushings are only $5.67 each from RA, so I've ordered those. Should be good enough for my purposes.

I seem to remember FAR made these in a non adjustable form at one time. Edit. The Delrin and aluminium bushings should be better than Poly. Much denser and self lubricating. The thinner the Delrin liner is the better, less deflection. Which is why the Del-A-Lum style is so good. The GM style uses an outer metal shell mainly because the bushings are supported only at opposite ends when installed in the stock stamped steel lower LCA. The middle part of the bushing has no support. With a Datsun Z front LCA, I don't think you'd even need the an outer shell. Just machine a two piece Delrin bush with a steel inner collar. Steel is better than aluminium to rotate on. That's what I didn't like about the FAR design. Now that I think about it some more, I'm pretty sure the Del-A-Lum inner Delrin bushing doesn't rotate. Memories a bit foggy, but I think the zerk fitting pins it in place and stops rotation of the Delrin liner in relation to the Outer aluminium shell. So all rotation is between the Delrin liner and the inner steel sleeve.

^ Thanks SJ. Don't know why I couldn't find those before. Was looking at there site for those as well.

Yeah.. I was looking at Techno Toy, but I couldn't find anything similar for the front LCA.

Does anyone know who makes Del-A-Lum LCA bushings for Datsun front LCA's. Specifically 240Z-280Z? Not looking for Poly and not looking for Mono-Ball. Specifically want the Del-A-lum style. These are for Third Gen Camaro's, but I want a similar product.

How often does Laguna have lapping days? I want to head down there for the Historic Races.

Looking much better. What anti roll bars did you end up with? How's the rear spring rate feel on the public roads? If front shocks are at the limit for rebound, or getting close to it, you can get them custom re-valved from Tru-Choice and a couple of other places. Bear in mind that brand new Koni's do tend to get stiffer as they bed-in. May take a thousand miles or so of street driving.

^ Very nice. Are those Manometers on the firewall? Checking individual port flow or balance?

These should give OP some basics as to good overall designs. Pay attention to injector placement and plenum design. You don't need the flashy CF and anodized finish to make something decent. Here is a picture of an SEM manifold next to the stock VW/Audi manifold. Runner sizing on VW/Audi engines is more than large enough stock ( We have 5 valve per cylinder engines ). Most of the improvements come on the Plenum side. Plenum is too small on the stock manifold. Stock manifolds does not have a very well balanced airflow to cylinders either. Custom Plenums produce some of the finest aftermarket manifold in the world. Very highly regarded in the Motorsport world. Check out the 2JZ-GTE manifold on their FB page for some design ideas for the L28. Yes thye do supply L28 manifolds as well. These are $$$$$: https://www.facebook.com/customplenumcreations SRDE20 Manifold

^ I was just thinking along the same lines as JP. 1: First the current injector position has to go. It is just wrong . You can buy weld on universal injector bungs and easily position the injectors in the right position on the manifold. Factory EFI designs and angles are a good starting point. You want the spray pattern to hit the backside of the intake valve . Right in the center of the valve is a good starting point. 2: Cut the " J " turn out of the manifold. Leave as much of a straight leg as you can on the flange side and the plenum side. Then weld the two sections together. Basically you should now have shorter runners with a larger diameter ( than the Factory NA EFI runners ) that allows a straight shot into the cylinder head. Win Win. Of couirse Plenum is now rotated 90 degrees, so you may have to reposition the TB flange, if it not a symmetrical square flange. With these modifications, particularly the injector boss re-location, you will have something interesting to test that will at least work. Look around the internet and you will find successful and proven high performance Plenum manifold designs that all have similar characteristics. Key points are: A: Injector placement as close to intake valve as possible. B: Proper plenum design. This can be very tricky, especially on Turbo engines. What looks right can be terrible from an actual distribution of air flow. There are some basics to follow, but using a pre-made factory or Custom plenum is a not a bad idea. Unless you have $100,000 or so of CFD computers and air flow testing equipment sitting in your basement C: Runners as straight as possible. No unnecessary bends to slow down airflow. Velocity is important even in a dry manifold. Some gentle bends may be seen in some of these manifolds, but that is only to facilitate port entry angle and hood clearance. Here are some pictures picture of proven designs for Audi/VW 1.8 5 Turbo engines. NA version is virtually identical. A good design for a NA engine will also be good for a Turbo engine, and vica versa. SEM manifold: 034 Motorsports manifold

OP wanted some advice and it was given. Main problem is placement of injectors. It is just bad and it's not " Buzz Kill " to point that out. If you don't think that is a bad placement... well go study injection and manifold design a bit more. That plumber J shape is going to collect the fuel that falls out of suspension after it hits the back wall as well. You can't change physics. As far as runner length. I should have said that it is too long for a high RPM gasoline engine. The factory Z manifold is too long as well..... for high rpm use, which in a sports car is what is to be it's expected use. Does make for good Torque, but at a loss of higher RPM power. Have a look at how short triple carb manifolds are compared to the factory L28 EFI manifold. Tuned Port GM engines have the same problem. Long, small diameter runners, engines fall flat on their face at 5,200 rpm ( 305 ci ) 350's horse power drops off after ,4800 rpm, because they use the same manifold as 305's. Good for torque though, below 2,500 rpm. I And I haven't assumed anything ZH. OP asked for opinions and I gave mine based on the sound knowledge that I have gained over 40 years of racing. It's a bad design IMHO for an L-Serie's and that is my opinion. Nothing more... nothing less. Edit: OP wants to make some money building these. I think he should test them. IMHO, the performance is going to be worse than a stock EFI manifold for the reasons listed, so it's fair comment to say that's he's wasting his time. Dyno tests will prove that out ( I'll put money on it ) . Not trying to be mean. Just giving my unbiased opinion to the OP. I'm said all I have to say on this... so continue on.