NewZed

I thought this thread was about a person you knew with indigestion and a bad attitude... If it was NA I'd say you had a lean condition, maybe a lean spot in the AFM or low fuel pressure. But the same should apply to boost I would guess. What's your fuel pressure? edit - pretty sure that the FPR raises fuel pressure under boost, just like it lowers it under intake vacuum. If the hose from the manifold to the FPR is off or blocked, you'll be rich off-boost and lean on-boost. Somethng to check.

Check your shift forks for cracks or excessive wear. They're expensive. If the shafts were out of alignment due to missing bearings, other problems can occur. That's probably what caused the cracked gear. The other gears must have had serious stress put on them too. You'll probably find enough other parts that need replacing that you'll wish you hadn't tried to rebuild, if you go that way. I'm no expert but it seems like a tranmsission with just worn bearings and synchros would be a better starting point for a rebuild. steved033 wins the guessing contest. Maybe he tried to rebuild his two and has some knowledge to pass on.

http://www.liveleak.com/view?i=3c7_1370751956

Looks like you're deep in to things. I noticed your measurements on the throwout collars and you might be measuring to the wrong spots. The critical dimension is from where the clutch fork contacts the collar to to where the bearing contacts the pressure plate levers. I modified one of your pictures to show it.

The Engine Electrical chapter of the FSM has a section on how the ignition system works. 1978 doesn't have a crank position sensor.

Wrong sub-forum.

Sometimes a click and eyeball search is better. Several good threads here - http://forums.hybridz.org/forum/92-turbosupercharger/

"for idle". The FPR has a hose connected to the intake manifold to drop fuel pressure based on intake vacuum. Typical idle pressure is 26-30 psi.

Are there signs in the CV shaft assembly that it is too short? Signs of wear? Maybe they're just wearing out. It doesn't seem like many people use the 280ZX CV shaft adapters. Haven't seen many accounts of their use. Here's a thread describing another adpater that several people have used. Up to an inch thick. It seems like there should be plenty of extra room for a stock 280ZX CV shaft. Go to Post #35 - http://forums.hybridz.org/topic/34048-more-questions-on-cv-axle-conversion/?hl=adapter cygnusx1 used to have another thread with prints of the adapters but it has disappeared.

You're starting a shop just to focus on pre-83 L6 Datsuns? What is your area of expertise - composite molding, tooling, engine building...? Just curious. Examples of previous or current work would be interesting.

Don't know why your idle would drop from1200 to 500, with a click. But, people get the AC compressor power wire and the BCDD power wire mixed up quite often. They look similar. Try turning your AC on and see if the BCDD clicks. And 37 psi is too high for idle. Sounds like you don't have manifold vacuum to the FPR.

In your case, the 81 troubleshooting chart is only good for ideas about how things work and some cause and effect clues. 81 had a separate Turbo Supplement that describes the three plug ECCS. The main 1981 FSM is for the 35 pin style ECU. The concepts are the same though. Sensors provide information that the ECU or ECCS computers use to determine fuel enrichment. Pretty sure that after the whole ECCS analyzer section in the EF&EC chapter there is some basic multimeter testing that you can do. You just have to work through the whole chapter. Take notes on where the good stuff is.

I opened up the 81 FSM, but it looks like Nissan changed things in 1982, to focus on the ECCS analyzer. Probably worthwhile to look at the 81 just to get some ideas. Nissan tried to make things easier but just made them more complicated instead.

Good luck. There's a third of a page dedicated to "Poor gas mileage". EF&EC 18.

You're probably seeing something else. Sounds like you just have a plain old externally regulated alternator, on an old 1975 280Z, with a bunch of old corroded connections drawing enough current at idle to put your headlights on battery power. Revving the engine provides enough current to charge the battery and run the headlights. A PO decided to replace one of the fusible links with a fuse in the past. Not uncommon. I plugged your part number in to Google and it comes up as an externally regulated alternator. You can move on to cleaning electrcial connections and fixing other worn-out stuff.

The engine wouldn't even run in the last post in your link, now you're driving it. Open the ZX FSM that fits the year of your engine and go through the troubleshooting in the EF&EC chapter. Check the CHTS circuit first.

I'm going to guess that your dad has big feet. Check where they've been.

Many of the mid-90's Nissans, like the Pathfinder, used a 3 wire power tranistor that looks like it would work. Ground, ECU Pin1 and coil primary circuit. Same basic design as the ZX turbo systems. The wrecking yards are full of them, or about $60 to 120 at RockAuto.com Attached a drawing from the 95 Pathfinder FSM, Page EF & EC 235.

Seems like there are three topics in play, and all blended together. Contoured counter weights for improved oil windage purposes (knife-edging), lightweight crankshafts (a side-effect of kinfe-edging), and harmonic dampers (got thrown in from the side from Porsche and VW land, although it should be considered when crank shaft weight modifcation is done, re the BJH white paper [which is well worth reading]). The original question was a little bit vague, and referred to the effects of losing crankshaft inertia (motorcycle-like response) unless he was implying that oil film drag was slowing the engine's ability to rev quickly. Seems like the purpose of knife-edging has been mis-defined a little bit and thrown the thread off-topic. From my limited understanding of all of these things.

Umm... I get 86mm = 3.385". Maybe your 3.25 is a typo for 3.35? Your gaps match 3.35". The factory range is in the back of the 81 FSM. Looks like your top ring is good and the second ring too loose. Are all of the second rings the same? You have six of each right? 76 (N42 block) and 81 (F54 block) are both L28's with the same bore and stroke. Pistons are different. The last few pages of the Engie Mechanical chapter has all of the spec. with ranges tabulated. Good luck. Looks like fun even witth the problems.

I checked my "How to Modify..." book by Honsowetz and he says .017" (.43mm) top, and .014" (.36mm) second. But Monroe and Honsowetz worked together, I believe. It was written in a different style though so it doesn't look like a cut and paste. I'm just repeating what I read. The 1976 specs. at the end of the Engine Mechanical chapter says: Ring gap Top .23 to .38mm Second .15 to .30 Oil .15 to .30 Honsowetz and Monroe recommend looser than factory spec. You have a dilemma. Edit - I see that the 1981 spec. is a little bit different, but not much. What is the diameter of the bore (after honing)? Weird though, that someone would ship rings with different gaps. Maybe they're reboxed returns. Aggravating to get bad parts that you can't evn modify to work.

Monroe's "How to Rebuild..." book says top ring should be "OK" at .3 - .43mm for an 88.9mm bore, recommends a target of .36 mm.. Second rings should be .05mm less since they run cooler. Page 121. BUT - then he says to follow the ring manufacturer's recommendations. So if you have a brand name (ITM) maybe you can find a spec. for mm gap / mm bore.

The quality of the clutch kit will depend on how well they copied someone else's design. XTD is Aimco, which looks like a typical off-shore copycat company. Here's an interesting couple of links. It doesn't look like they manufacture anything in the states. The contact e-mail address is a yahoo.com address. Just shining some light for those who want to know where these great deals come from. http://www.xtdclutch.com/cms.php?id_cms=4 http://www.ripoffreport.com/r/aimco-clutch-company-ebay-id-aimcoclutch/los-angeles-california-60007/aimco-clutch-company-ebay-id-aimcoclutch-jim-kun-song-xtd-racing-clutches-sells-automot-378941 EBay is a crap-shoot. Hope for sevens...

Forgot to say that once the engine warms up the temp. switch is out of play. So if keeping the engine running when it's warmed up is the problem, that won't fx it. All the switch does is cause your timing to advance about six degrees when the engine is cold. If you add some detail to "stay running" someone might have some ideas.

People have made the switch linked to below work. I don't think that the original is available anymore. http://www.thezstore.com/page/TZS/PROD/11-3122 But all it does is activate the second pickup coil in the distributor when the engine is cold to advance the timing. Either for emissions or just a more convenient idle, its purpose is not clear. Described in the Engine Electrical chapter, Ignition Circuit section, of the FSM. If it's not there, you just don't get the cold temp. timing advance. www.xenons30.com/reference You'll barely notice a change if you fix it (the idle will be higher for longer when cold), but if you do, an alternative fix is to run a very small metal screw in to the wire stub in the center of the broken one. Put a tiny ring on the end of your wire with the bullet connector.