Captain Obvious

10 MPG ought to be easier to find than this... Those plugs don't look all black and sooty as I would have expected. At 10 MPG, I would have expected loose fluffy.

I've not gotten to that part of the circuitry yet, and I may never get there. but I'm not buying the 4500 RPM limit either. It takes much more air and fuel to run WOT up a steep hill at 4500 RPM than it does sitting still no load in neutral at 4500 RPM in the driveway. There's no way you would want the same amount of fuel injected under both of those conditions. I won't deny it if someone shows me the circuitry or the test results, but until then... I'm not buying it.

Great! Repair looks good and it sounds like you're back to reasonable numbers for where to put the screws. Glad you found someone who had the welding skills to do the repair!

I'm traveling so my resources are very spotty, but I can tell you that pin 6 Is a ground line. It's an analog ground for the sensor, so yes, those two parts ARE in series, but not in the usual sense. Yes, if the temp sensor in the AFM has gone open circuit, you will run rich.

Sorry to hear about the continued troubles. Are you sure you're using appropriate injectors? And have you ever tried another ECU just to see what happens? Wish we were closer together, I'd be happy to do what I could to help.

Forgot to ask... Which ECU is running? Is it that newer one with the DIPs?

Excellent! So now it's on to the next hottest fire I assume. Liked the thumbs up BTW!

Here's a bunch of details of what I did: http://www.classiczcars.com/topic/48758-suspension-refresh/ http://www.classiczcars.com/topic/48621-steering-rack-disassembly-and-refurb/

I'll offer another perspective... I've seen several incorrectly fitting and incorrectly installed poly bushings in my travels. I know for a fact that on my car, my PO had installed poly bushings everywhere and the car felt horrible and handled like crap. I took most of the poly out and replaced with rubber, but during that process I found a long laundry list of issues with the whole job. Some bushings designed poorly and not fitting properly. Some bushings installed incorrectly. Some related suspension bits not put back together in the right order and/or orientation. I bet that if the bushings are designed properly, fit right, and are installed properly the car will feel very different than what happens on a lot of installs. In other words, I believe that some of the suspension issues that are attributed to poly bushings might not be the bushing's fault. The bottom line is that if you're going to compare a poly install with a rubber install, you better make sure both installs were done right or you might not be doing a fair evaluation.

I've not seen that phenomenon on the round top carbs, but I've seen it on the 280 throttle body as well as other throttle bodies from other unrelated cars as well. Perfectly smooth when off, but sticky with vacuum pulling against the butterfly plate with the engine running. I won't claim to fully understand exactly what's going on, but in my experience it's been caused by either worn throttle butterfly shafts as suggested above, or by dirty crud on the butterfly and/or throat walls where the butterfly meets the walls. So first suggestion would be to hold the carbs butterflies completely open and thoroughly clean the the interior walls of the carbs and the butterflies really well with a carb cleaner wetted rag. Might be tough with the carbs on the car, but you could remove the domes and suction pistons and that might allow enough room to get in there without taking the carbs completely off. If that doesn't help, then I suspect the chrome plating has worn off your throttle shafts exposing the brass underneath (very likely). You could put some lube on the shafts and work them around. That may help temporarily, but to really fix it, you'll need more dramatic measures.

Excellent. I love it when a plan comes together. Good thinking on the cable re-route to make future work easier. I should have done that too. This whole thing reminds me that I gotta pull my dash... I've got a leaking heater core and I also need to do some electrical work for a headlight relay upgrade. Easier if I just pull the whole dash. My car has been in hibernation, but Z season is fast approaching! If I remember, I'll reroute that cable while the dash is out.

They probably put that aluminum portion at the bottom of the cup to add additional material for threads. And they probably used aluminum because it's easier to machine than steel. It's clearly swaged/peened in place and I doubt you would be able to get it out in good enough shape to be able to bend it a third time back into place without cracking it. In fact, I doubt you'd even be able to get it out without cracking off the material that's been bent into retaining position. Hmmm... So ideas? 1) Drill it out, make a polished aluminum replacement with a few threads on the inside and use a nut to hold it in place. You got room for a nut on the inside? 2) Drill it out, make a steel replacement, silver braze it into place, and send the whole thing off for plating as a unit. 3) Carefully drill/grind off as little of the the peened material off the inside required to get it out and then JB weld it back into place after plating. It's gotta hold vacuum, right?

Wow! Shiny!! That's a great finish! PS - I see you!!

John, Thanks from me too.

Cool. I'm assuming this is one of those electronic flashers we were talking about near the top of the thread? Did your flashy bulb burn out already, or are you just planning ahead?

I believe the intuition is correct. The highest of the forces should be compression straight down the rod. And after all, one mm off the diameter is only a half mm off the radius (about 20 thousandths for us US folks). I'm no engine builder or materials science guy, but my seat of the pants engineering says I wouldn't be concerned about taking off .020 of material. Anyway, I know it's academic because you're not ready to try to tackle a job like this, but if you were, you juuuuuust might be able to get that on your lathe. The FSM says the rods are 5.13 inches "center distance", and I assume they're taking center to center between the two bearing surfaces. With the big end lower cap off, you just might be able to swing it. (Get it... Swing it?) Haha! I kill me.

Never heard anything about it, but wanted to ask... What's the swing of your new lathe? You might be able to do this yourself if you decide to go that route.

And later in the lube section it says that the pressure relief valve in the pump limits the pressure at 80psi. With those data points, I consider 70 psi at 3K warm to be just fine for an engine with a well done fresh bottom end. Now, if the pressure was like 90 psi at idle when warm, then I'd be a little more concerned about the bearing clearances, but this one sounds like a non-problem. Diseazd, I know you're not worried anymore, but if you do another turn around and decide you're worried about it again, I'd be happy to trade for my engine!

Well, considering the alternatives, that's awesome news! I am surprised that the failure was enough to actually stall the motor while it was running. I was figuring that it was straining and squealing, but finally locked up good while stationary. Also surprised there wasn't shrapnel. Anyway, awesome news. So I went back to the very beginning of the thread where you were questioning your oil pressure numbers: "My 71 240Z (L24engine) runs 75 lbs. of oil pressure at 3000 rpm." Don't know why I didn't mention it before, but I'm not sure I would have ever even called that a problem. You get 75 lbs at 3000 RPM (when hot, I assume)? So what? Sounds like a healthy bottom end to me. I assume it drops off at idle? I've seen the "10 psi for each 1000 RPM" tossed about, but my understanding was that was a minimum before you needed to do something about it. Not what you could expect on a new healthy motor. Frankly, if I had a freshly rebuilt bottom end and only got 30 psi at 3000 RPM, I'd be disappointed.

Haha! He said the motor is fine. There are clearly some clutch parts that are completely FUBAR, but the rest of the motor is fine. Frankly I'm surprised there wasn't a more spectacular failure with shrapnel. I'm guessing it was squealing like a pig and he shut the motor down. The front of the throw out bearing and a bunch of pressure plate fingers were all liquidy hit in spots from the friction and once it stopped turning, everything welded together before they cooled

Been a while since I messed with oil pumps, but IIRC, the turbo oil pump is longer to accommodate internally longer rotor gears. In other words, you might be able to tell that from the outside?

Wouldn't matter what gear the tranny was in. The fault was upstream from there. My interpretation is as follows... Throw out bearing was installed incorrectly, and as such, was always loaded. Problem is, they're not designed for that. They're designed for intermittent loading only (when you push the clutch pedal in). Throw out bearing worked for a while before seizing internally. Now the front part don't turn no more and the disk which is supposed to spin with the pressure plate is now sliding against the fingers. This caused the front part of the throw out bearing to get so hot that it welded to pressure plate fingers. Front part now stuck to what wants to rotate. Rear part never rotates. Something's gotta stop... Or give.

Good step forward. Now you'll have to crawl under the car. I can't stall you anymore. PS - Nice pics!

So on the good side, your motor is fine. On the bad side, you still have no explanation for your high oil pressure, right?

Whew. Good! I was hoping I was remembering that right. All I remember was that I was having a heck of a time measuring the ratio on a diff out of the car. Nothing was making any sense until I locked one of the axle flanges in place.