BRAAP

Need to know what year of harness you are working with as the pin outs are different for different years. Based on another thread you have going, I'm guessing it is for a '78?

Based on the FSM, what pins are "supposed to be" HOT +12 volts when the key is turned on? There should be at least one other pin that is hot, i.e. power "for" the ECU, maybe more. If they are not hot when they are supposed to be, start tracing those wires back till you find out why they are not hot. I have no idea what you just said? English must not be your native language?

I think understood you to say that your wired the '78 harness exactly to the '78 FSM and are using a '78 ECU, ('77 ECU was a spare and now realize it wont work at all with a '78 harness.) If you rewired your '78 harness to a '77 diagram?.... If all is good, then using the FSM wire diagram you should be able to trace out which wires are supposed to be hot and when. Also double check that your EFI relay is indeed the correct one and operating correctly. They changed internally and I am pretty sure the '78 EFI relay is particular to itself, i.e. you can't use a different relay on the '78, (not 100% sure on this one though).

I know Subaru and Nissan use the the same diffs from one manufacturer, (Subies still using the long nose variant). Whether or not it is the same manufacture for the Yota diffs, and even the Mitsu diffs, I don't know? Maybe JMortensen, Tony D, or someone else would know? If they are the same manufacturer, the internals very well may interchangeable. Now wouldn't that be cool.

First we need to verify a few things, just in case. You are using a ’78 ECU and a ’78 harness correct? You mentioned rewiring the ’78 harness using a manual. What manual did you exactly use for that? If the OE Nissan service manual which year? I'll cover this again. The ECU does not read or sense the cold start anything! The ECU doesn’t know or let alone care if the cold start injector is open, closed, or even installed on the engine! It does not use anything from the cold start to base or control the other injectors! Yes it may very well be opening up allowing fuel into the intake which your engine is running on until the cold start injector closes. For the intent of this discussion and your current EFI issues, the cold start system does not pulse nor is in any way affiliated with the 6 main injectors. It just opens for a few seconds and that’s it! It appears to be operating by your description, but again, it has absolutely, positively, 100% NOTHING to do with the rest of your injectors operating or not operating, unless you accidentally wired it to. They are supposed to be two completely different and separate systems! In this link given earlier; http://atlanticz.ca/zclub/techtips/efisystem/280zfuelinjectionbook.pdf Page 16 and page 17 covers the cold start system, (Thermo time switch controls the cold start injector). I don’t recall part numbers, but you will notice the pin out of the ’78 is totally different from the ’77. Your harness is ’78 correct? You mentioned your rewired back to ’78 specs per the service manual? The ’78 Nissan service manual? If you went by the Haynes manual, it doesn’t cover the ’78, only the ’75-’77. 1) Power to the injectors, good! 2) Fuel pressure, good! 3) Engine actually runs on supplemental fuel, good! 4) Tach is moving/bouncing while cranking, good! 5) Injectors are not clicking while cranking. Now we have a more definitive focus for troubleshooting. Need to find out why the ECU is not pulsing the injectors. Verify the ECU itself is getting power. (Just because the injectors have power does not mean the ECU is getting power). Just as JSM covered previously, unplug the ECU and using the correct wiring diagram, verify that you have 12v to all the pins that are supposed to be hot. You may have to turn the key to on.

No. Toyota does not share the same diff with Nissan/Infiniti.

These early ECU's are not thinking ECU's. I.e. not like modern OBD-II cars. This EFI is very simple, just like most basic electrical circuits in the car. again, not a thinking ECU. The Z car ECU does NOT read from the cold start system. I have been tinkering, monkeying with and researching this EFI system since the late '80's have learned TONS about it in that monkeying, such as how and when it fuels, what sensors do what and why, etc. Successfully got a 2800 lb 280-Z with stock EFI and stock cam to run 14.4 @ 97 MPH, (0-60 MPH in 5.7 seconds), while delivering 28-30 MPG on the freeway! Played with mechanical actuation of the AFM in and effort to remov it from the air stream, various TPS switches with WOT clocked at different positions, micro switches added the throttle linkage that were tied into resistors that altered the water temp signal at various throttle positions for specific fueling under various conditions, etc. What I learned was the stock EFI is very robust, is limited in how far you can tune it, is quite easy to diagnose and the cold start system is all but entirely useless. I have successfully removed the cold start system in varying degrees of "deletion" on at more than 100+ Z cars. In short, just delete the cold start system. It is doing you and your car no good and possibly only adding undue confusion to your situation! Trust me! Ok, lets gone on to the problem at hand. a) You have fuel pressure. b) You have ignition as the engine will run a supplement fueling source. 1) You mentioned spare ECU's. Being as ’78, it is its own regarding ECU pin out and harness. You can not mix a 78 ECU or harness with any other year ECU or harness. 2) Do you still have the dropping resistors near the clutch master cylinder plugged in? 3) Do the injectors “click-click-click” while cranking on the starter? Using a mechanics stethoscope, listen to the injectors! 4) With key ON, check for battery voltage at the injectors themselves. You should have voltage, (approx 10 volts or so) at both terminals of each injector connectors. I know, that sounds weird that both are hot, but that’s the way it is. If you do have power, need to find out why they are not getting the pulse signal. If no power then start tracing the power wire from the battery, fuel inj. relay, fusible link in the EFI power harness near the battery? etc. 5) If you have power to the injectors, adequate fuel pressure, but no clicking injectors, (it runs on supplement fuel so we know the ignition system is working), verify the ECU is getting the engine RPM signal. 6) Does the tach move while cranking the engine over? If no, more than likely your ECU isn’t getting the RPM signal, as well as the tach, (ECU and tach get their signal from the same wire). Under the dash, driver side follow the ECU harness from the ECU to a small run of wires that come out of it to a 6 connector plug. Only 5 of those connectors are being used. One will be the RPM signal. 7) Just for giggles, unplug the little spade connector from the starter and turn the key to "start"! Do you hear the fuel pump come with the key in the start position? I’ll stop there for now. Go check this stuff, report back with your findings and we’ll move on from there. I may not reply right away, maybe even a day or so between replies, but I will try to help as I can.

Roger that. It was starting to sound like TPS short out like when we wash the engine bay.. Delete the cold start system all together, especially living in Florida! Cold start is just that, it is for cold starts. I mean really cold starts, like in the fridgid white north, and at that, it is debatable if it is truly needed. Even up here in Oregon where we will see temps below freezing in the morning when we go out to start our cars, on all the 280-Z’s that I have deleted the cold start injector, my cars, customer cars, friends cars, several cars, all of those cars still start just fine, even on the really cold mornings. Cold start injector circuit is not needed. When well below freezing, the cold start injector may help the engine to fire off a couple of crankshaft revolutions earlier vs. not having it, but if your battery is good, those couple extra revolutions are not an issue. In Florida, you shouldn’t notice its function anyhow. Remove the cold start injector and put a plate over the hole, (using some gasket material to seal it). In a pinch, just cut the fuel line going to the cold start injector, plug it on the fuel rail side or install a plug in the fuel line itself so visually it looks OE. Electrically, you can just leave it plugged in or just unplug it, wont hurt the ECU or anything else. Hope that helps.

Aux, You are starting to worry us bit...

Seen that a few times, back in the mid-late ‘90s working as an apprentice machinist/engine builder. One was a little old couple who purchased a brand new Ford Crown Vic, was told by dealership it could go 100,000 miles between tune-ups. They took that to mean oil changes as well. At approx. 60,000 miles engine seized. The shop that did the engine R&R brought the engine to us, we disassembled it, and WOW! Oil separated into big globs of paraffin wax just like in the pics of the BMW. My favorite was the idiot that brought us his Dodge V-6 engine from his Dakota. Said it just quit running one day, wanted us to rebuild it for him. I get the pan off and the pan is a thick gelatinous goo, tip the pan up side it doesn't fall out! A little more digging revealed this was some Dodge factory/dealer Re-man engine, (tag riveted to the block). We ask him about that and he say this same thing happened to the original engine at about 80,000 miles, had the dealer install the reman, this Reman lasted approx 60,000 miles. We asked him if he ever changed the oil, he assured us he had not because it was a waste of his time and money! Cause you know, replacing engines is sooo much cheaper and less hassle... We rebuilt the engine and assured him there was no warranty wih this engine! Here is a of one of those that came into the shop back then. I think this was the Dodge pan, may be a SBC or SBM. Sorry for the poor quality, it's a picture of a picture.

Unless the CFD can simulate the air flow, pressure waves, and overall fluid dynamics of the air mass from opening and closing valves due to piston movement, (taking into account valve timing in relation to piston motion during valve opening/closing), at various RPMs as it enters, transitions, and stirs about pre, and post TB, the CFD display and computations will be approx 90%-100% useless. Sorry, not trying to discount the abilties of CFD, but in the application of an Otto cycle engine, unless it can simluate the dynamics of the air mass as the engine sees it, helmholtz, etc, static air flow info is only barely partially valuable in finding that answer.

John, I am going to need a few jars, one of which goes to Ronholio... You accept PayPal right?

Or build your own version of the CTS-V, BMW E36 4-door with LSx.. http://forums.hybridz.org/showthread.php?t=150253

Interesting, thanks for sharing. Great videoagraphy and editing. Saw a bit of love for the old Datsuns, 510's etc, only one S-30 though. And it was that...

First hand experience this weekend with how important a commonly overlooked aspect of tires really is. Production date. Tires don’t last forever and over time become extremely unsafe. We bought or 33 foot 1998 Winnebago Chieftain Class A motor home a few years back, tread looked great, 75%+ tread, I regularly make sure the tires have adequate pressure before we use the motor home etc. Didn’t once think to see just how old these tries are. Made a trip to Disney Land summer of ’08, sever camping trips to the cost, silver falls, we take it to Medford for Thanksgiving to see my wifes father. This trip to Medford I removed all the tires checked the brakes, lube the caliper slides, verified tire pressures, anti-seized the wheel studs, reinstalled the wheels. Got into town filled up the gas and propane and off we went to Medford. 5 and a half hour drive non stop in the motor home. Had a good Thanksgiving, (other than forgetting my favorite jam in the whole world in my father in-laws fridge), we get half between Grants Pass and Medford and loudest boom we had heard just shook the motor home, lot so flappety flappety flapping coming from the passenger rear. Instantly knew what it was, lifting off the accelerator, came to slow stop on the shoulder, verified blown tire inner passenger side dual! We are the Valley of the Rogue state park Rest area so I limp the motor home in the rest area to change the spare. Call for Les Schwab to come out and help. They replace the tire with a brand new one right there in the parking lot. Tire guy noted the date of the tires were 1996, most likely original tires! He attributed the blow-out to age. Back on the road just south of Salem, another huge explosion, right front corner of the motor home drops approx 9”, CRAP! Motorhome was slightly pulling to the right so I let it pull as I lifted slowly off the accelerator again, not wanting to upset the 50 MPH forward momentum we had. Slowly nursed to the shoulder, passenger front blown out and it’s now dark! Thank goodness we elected to have Lesters install a brand new tire for the rear, still had good spare to use. Rest of the trip home was 45-50 MPH, white knuckle ride, puckering up over every bridge seam, pavement ripple, etc! Next trip of the Motorhome is up to the tire store for complete set of new tires, including a brand new spare! We were very fortunate the blow outs didn't damage the motorhome. Wheel wheels are 100% intact, brake lines un touched, etc. Only damage was the rear mud flap folded up a little, was able to straighten that back out. We were very fortunate. First pic is the rear tire, second and third shots are the front tire that blew! Moral of the story, don’t judge a tires condition solely on tread or lack of weather checking! Check the date code as well and don’t drive on old tires!

1-6 = Haynes manual?

Revs to 3200 RPM and no more, like a violent rev limiter? Shuts off at 3200 RPM and comes back on at say approx. 2800 RPM?

I could totally see Bawb Dawg behind the wheel...

Couple more;

Caddy Northstar, Wooden super car, aka "Splinter" being scratch built.

This thread on Huge-by-large throttle bodies on small engines comes to mind here... Click me. Big Throttle bodies.. WHY?!?!?!?

The uber short truck injectors? Looks like it can be done, will require one of a couple different alterations to make fit. 1) Slot the mounting holes in the fuel rail as I did, but even further and also slot the mounting tabs vertically for the lower stance. 2) Build new mounting tabs with correct offset and elevation in the mounting holes. This will place the fuel rail lower which will make access to the intake manifold mounting bolts, (bolts that attach the intake to the heads), difficult to get to, possibly even touching the those bolt heads. Probably just mount the fuel rails after the intake is installed on the engine?

John, I need a fix! I took my jar of jam down to Medford for the holidays and forgot it there in my father-in-laws fridge! It wont go to waste there, but I don't have any now...

Seen more than a few mentions of under the seat. I would agree that is a great choice for space reasons, but disagree with using that location for an ECU or any other electronics item, "especially" in a street driven Z, and double especially in a wet climate. S-30's are known for their rusted floor boards from standing water due to leaky windshield and sun roof seals. Learning of a new windshield/sunroof leak by finding dead electronics under the seat, in particular the engine managment system, is not my favorite way to discover such a leak. Just my opinion. Kick panels are ok, under the dash is good, mounting it up high in the glove box, (to the ceiling of the glove box), is a great location especially if regular access is required. In my old 240-Z race car I mounted the MS ECU on top of the trans tunnel just under the dash.

John, Oh yeah! I’ll take it! You accept PayPal? When just “trying” this jam, say off the knife/spoon, etc, nothing else to soften the blow, it is VERY hot! But with something that softens the heat, this is absolutely phenomenal! My new all time favorite late night snack! Ok… cut a whole Sourdough muffin in half and toast both halves. Then with a heavy layer of Philly Cream cheese spread on the freshly toasted muffin, spread a thin layer of this incredible jam. Mmmm…. Tames the heat to a very tolerable level! Night before last, went so far as to make 4 halves! Tonight, same thing, 4 halves! This stuff is GOOD! Trick is to use something that tames the heat, and a lot of it! Cream cheese works wonders! Heat level is just enough to enjoy, not too hot to trash your taste buds… Yes John, I’d be glad to take another jar off your hands.