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I am in the process of refurbishing a pair of original battery terminal cables. After removing the terminal clamp bolt on the negative cable, I noted that bolt (6.0 mm x 1.00 mm x 1-1/4") had a rounded “U” head to match the profile of the terminal clamp. As you can see from the attached photos, there is no indication that the bolt head was modified with added metal to reshape a square or hex head bolt to form the rounded edge. Has anyone else seen a terminal clamp bolt with this rounded “U” head? Thanks, Keith

Patrick Bateman's favorite song.

This was a huge help for me since I had no clue about the carbs. I'll also add mine was a hard start too until I adjusted the valves. That helped a lot.

S30.World.com, order one and consider it done.

I have to ask why not just keep a set of spares that are still functional and enjoy the car? I applaud you for trying to fix the ECU if that is the end result you are looking for.

hanks for the tips, I was using the choke. I need to give the carbs a once over in general, as it hasn't started right since I got it, I just had to deal with the gas tank first (which has taken forever) so haven't had a chance to get back to it, but slowly getting there

Extensions just need some heat shrink but are otherwise ready. Testing tomorrow is go.

Well, sports fans, it looks like we are in luck. Tick-tock.

Or Jegg's possibly? I would think you could find one on the side of the road. It's not like it's a radiator cap for the space shuttle. Your OCD is making things a lot tougher than they are.

I can hardly wait until you start bashing it with a hammer as Zed Head mentioned, then posting the results. Should be a hoot!

Actually, I should first do what @Captain Obvious suggested and check the choke coils. Then the above. I'm afraid I have honey-dos today so this will have to wait until tomorrow but I'm sure everyone is on pins and needles...

Hey Z-sters! I'm finally getting around to addressing the hood on my '72 240Z, which had been banged up, bondo-ed and repainted under previous ownership and needed to be addressed. I removed the paint from the corners, to evaluate and repair/strengthen before repainting. (see my attached photos attached). Can anyone send me photos of the underside of a 240z hood - specifically the front lip corners and middle as shown in my photos) so I know how it SHOULD look? Buch appreciated in advance! Jughead

Many thanks to you both. I love the idea of testing with the lid off, I should have thought of that. Since the refurb unit won't be here until mid-week I think what I will do in the interim is the following: 1) Assuming I have enough connectors in my bins, make 26 individual extensions so I can "plug the harness" without actually attaching it to the ECU 2) Install the ECU sans case, but connected with my 26 little piggies 3) Run the system 4) Thump the free-floating harness plug 5) Wiggle/Tug every individual connection 6) Use a spudger to do delicate tap/wiggle tests on every little thing inside This should be interesting.

I had one of my masters re-sleeved, due to pitting in the bore. Works great with new seals and been trouble free for over 4 years. I'd rather rebuild and refurbish original components if they can be, newer parts don't seem as well made. Thanks for checking your clamps, I'll go with what was on the Green 5/70 BAT 240Z as it was low mileage and relatively untouched.

Go to the summit racing website and order a new champion replacement.

It might be fun to run with the ECU cover off. When you kick the case all of the components feel it. With the cover off you can pick the one you want to test. Hit it with a hammer, wiggle it, whatever. It is odd though that two ECU's would have identical failure characteristics. Might be worth the tme to do a pin drag test on the active pins in the connector that CO shows in his diagram. Maybe you have a loose one.

Well, certainly if you see something pop up for brake master guts, I'm all ears. There's one guy on ebay who has them, but I'm struggling with the price. I'm not sure if the master I have here would work even if the guts were new. I'm not digging the idea of spending over $100 as a gamble just to see if it works. And I wish I could help you with the wire clamp details, I've got original clamps here, but they are all aged to the point that it's quite doubtful I could tell what color they were when new.

The input filters could certainly become intermittent if vibration has taken it's toll. You could put meter across the visible wire coming off one side of the input choke coil and it's corresponding ECU connector pin. Should be pretty easy to figure out which pins they are filtering. Many of them are dead shorted, but the few (three?) that have the coil installed should be easy to determine. Looking at the approximate positions of the filters on the board and the pin functions of the ECU I/O connector, I'd guess that the filters are on pins 7, 27, and 13. Those would be inputs to the ECU that would be susceptible to noise. Those pins are 7) the AFM slider, 27) the air temp input, and 13) the water temp input signals respectively. But of course, that's a guess from across the interwebs. Here's a crude sketch I whipped up bunch of years ago. I know this info is available in other forms, but this form made sense to my brain: So about the failure mode for the Darlington outputs... No, they would probably not fail in the mode you are seeing. HOWEVER, the solder joints TO those transistors could fail with the symptoms you are describing. Any solder joint on the board could potentially go intermittent over time, but it would be unlikely for most of them. Vibration, stress, and temperature would be the risk factors. So about those risk factors... The reason those output transistors are so big and bolted firm to the chassis is that they get hot. There's your heat risk factor. And the I/O connector gets mechanically stressed every time you move the wiring harness or attach/detach the harness to the ECU. There's your stress factor there. Bottom line... If I were looking for a failing solder joint, I would start at the I/O connector and the output transistors. However, all that said, if I'm placing a bet at window #3, I'm betting the root problem is not inside the ECU case.

The ignition system is stock other than the wires and plugs. I did replace the coil many years ago, and maybe the ignition module a few years ago. I say "maybe" because I can't remember if I kept the original (which tested out perfectly) or swapped it back in and put the new one back in my parts bin. The problem that go-around was simply the car battery. Fun fact for anyone playing the stay at home version: It is possible for your battery to have plenty of juice to turn over your car and still be low enough on voltage so that your injectors won't fire. That was a fun one to diagnose. I can say for certain that the tach is spinning as normal and at least the tapping is not imaginary. I can make it stumble/stall 100% if I upgrade the tap to a "knock". However, it is entirely possible that more than one thing is going on and the stalling without tapping or opening/closing of the door could be something else entirely. Problem 'B' doesn't care one lick if you are already dealing with Problem 'A'. Alas. It looks like my order finally got out the door but it won't arrive until next week. We'll soon see what the future holds. Now taking bets at Window #3.

What ignition system are you using? The ECU uses the coil voltage pulse to trigger injection. Maybe the problem is actually in the ignition module. The coincidence with the tapping on the ECU might be imaginary. No offense, the human brain can rationalize itself in to knots. I had thought of this earlier - if the problem is repeatable and you can make it happen while you're in gear and moving, the tachometer should still show RPM if it's the ECU crapping out. If it's spark related the tach will drop like a rock.

Just a gut feeling, but based on the how-and-where-and-how-hard I tap on the ECU/connector, it seems like there might be a break in one of these coils...I think this only because they can rattle around a tiny bit in their respective tubes and would likely still "settle" with some sort of contact again because of the confines and 45+ years of work-hardening through vibration might do them in. I'll try and have a peek down the tubes with some sort of magification and see what I can. Alternatively, based on your comment about the darlington transistors, is this any sort of failure mode that makes sense for them? Where rattling or knocking with make them fail temporarily? The very temporary nature of the problem is what is most baffling to me.

Haha. Indeed. This is me, all day every day. No matter which way this goes, I will be using at least one of my ECUs as a learning/traning tool to do a refurb from the ground-up and truly learn every last function, and to really play with tuning. This is why I already had: A spare ECU, a spare AFM, the FSM, the FI Bible, Bosch Fuel Injection & Engine Management, an Ignition 1-2-3 distributor, and an oscilloscope...as well as a host of articles and posts from around the Internet. But I had planned to do this on my own schedule. It seems my Z has other ideas... In related news, last night I discovered that rebuilt ECUs are actually a dime a dozen; I just failed to Internet properly. I've fallen into some sort of pavlovian response mechanism where I assume everything is unobtainium and start scouring ebay and specialty z-parts shops. But if you look at AutoZone, O'Reilly, RockAuto, NapaAuto, etc. a rebuilt unit can be had for as little as $200, or $175 if you are willing to return a core. I've now re-added the standard parts-jobbers for future needs. It looks like they still have some bits and bobs. If it is useless I can return it no problem, so I figured: why not? When it gets here I'll do some compare-and-contrast. More news at six. Film at eleven.

Ball joint failure is a real thing. It usually causes major damage and loss of control. So the calculation is about how close a person wants to get to that catastrophe. Which also endangers other people on the road. But in this case, Nissan has given an inspection procedure. If it meets spec. why replace? What's odd is that they say that the ball joint cannot be disassembled, when, obviously, it can be.