DAW

Yeah Dave you're probably right. I had a wind-powered generator on my 1939 Luscombe (airplane) that kept the battery charged for radio & lights use; items that weren't on it originally, and it had no provision for engine-mounted generator or starter (magneto ignition, hand-prop start). The generator hung down on a bracket under the plane and its small prop was turned by being pushed through the air. Maybe I should have explored switching it into a motor mode to help with the short-field take offs (the engine was only 65hp). An electric turbo doesn't sound very efficient, but how about a driveshaft-driven compressor for filtered pressurized air stored into tanks which could augment a conventional turbo system, especially with valving to distribute the stored charge to combat turbo lag...DAW

When you bumped up the initial by 9 degrees you should have been able to then back off the throttle adj screw (close the plates down) and expose less of the ported vacuum slot for the same idle rpm. Before the change, your total advance was too low and it was "distributed" at a suboptimum rpm. I expect he'll see an improvement in mpg as well as performance. DAW

Pete, the method you describe has got to be the more effective way as it is tuning for power, using empirical results. It is a much larger project though. The ping-parameter method is just a ball-park means of roughing it in (and usually big improvement over stock or random trials). I think the ping-parameter or endpoint is more of an engine protection measure than a power tuning method but ultimately it is a selection towards optimum stoichiometry for a given rpm and load. Measuring acceleration changes is far more direct and accurate than muddling around with teasing the engine with ping parameters. An A/F monitor would be a good thing with either method and would provide a common denominator when correlated with a specific rpm and timing setting. DAW

Nathan, with your regrind do you recall what lash pads you needed to put in? I'm thinking the stock lash pads are usually .160". I was wondering if the difference with a regrind is anywhere close to the difference in length between 280Z L28 valves and 280ZX L28 valves. DAW

Addendum: BTW, when I recommended "richenning it up" above, I mean by changing jets, etc (Webers), needles change or reshape (SUs), or sensor/CPU changes (EFI); not just trying to richen the idle circuit. Also, with a lot of ECCS and OBD-II type systems most of the above doesn't apply because the computer manipulates the parameters and eliminates the middle-man (the tuner). DAW

It helps to know the distributor specs as to how much advance is available in it because you don't want to go too high on total advance, nor put in too much initial timing (which can cause the starting problems, light load ping, etc). There are a lot of variables as to what's right for a particular engine, and a lot of opinions and experiences. For an engine with at least some mild mods like increased compression, initial (static) timing of 12-15 degrees is a reasonable place to start. Add the distributor's contribution from its specs and make sure your initial plus distributor (make sure you convert distributor degrees, if given in specs, to crankshaft degrees (and rpm) or they will be off by a factor of 2) totalled together isn't much over 38 degrees. In many cases, by increasing the initial advance over stock you will also put the total where it will benefit performance over stock and you have shifted the curve of advance to the left across the entire rpm range. Still, that may not be optimum yet and increasing the distributor's rate of advance may provide further benefit (switching to lighter advance mechanism springs or heavier weights so that it is all in by about 3500 engine rpm). If 38 degrees total advance is reached with only a few degrees of initial advance, then you need to somehow limit the distributor's advance contribution so you can run more static timing without going too high on the total. The timing with the ping method can work well especially for trying to get all you can out of a stock distributor. One approach would be to set timing at 12 degrees and listen for a ping on the road. Mid range acceleration on an uphill is a good situation. If it pings on good quality and octane fuel there then I'd look to the fuel delivery instead of backing off the timing. Richen it up to get rid of the ping then try advancing a few degrees more until it pings again and then split the difference, backing it off towards the point it initially pinged, before enrichment. With a higher than stock compression engine the overall performance can be significantly improved, especially the throttle response, and the fuel tuning will also protect the engine from damaging detonation. Once you set the initial timing, scribe a mark at the distributor base as a reference point so you can make changes at the side of the road without needing a timing light. Once it's sorted out you can measure the result with a timing light and note for future tune-ups. DAW

I use Bosch platinums in my family cars and I've used NGKs with good success (that includes not having to change them frequently). For a higher performance or racing engine I haven't found platinums to make much sense because there are fewer choices in heat ranges in the platinum lines of most brands (and sometimes the retailers will try to put the round peg in the square hole, so look up your application yourself and cross-reference to confirm); and due to the cost...there will be a lot more plug changing in the high performance engine and a fresh set of steel electrodes probably perform better than a set of the more expensive platinums which are good condition but higher mileage. If there aren't a lot of tuning changes going on then I've usually run platinums in the street turbo cars I've had (Talon TSI, Volvo 940Turbo, Starion ESI-R, L28ETs) and felt they're worth the higher initial cost than regular plugs. DAW

The comment about the platinum plugs was meant in a general way re assuring quality components in good condition have been established before efficient troubleshooting can be done. Cutting back to the chase, and assuming the basics have been addressed first, the loping erratic idle and a severe mid-range hesitation may well be a vacuum leak or over-lean condition from such things as a crack in a vacuum hose (or a hose pulled off), a sticking door in the AFM, a bad input switch or sensor for the ECU; or from erratic fuel supply due (assuming the filter has been replaced, and the gas is good, and the system isn't all gummed up) to corrosion on injector connectors or harnesses or ECU, or something as obscure as the venting for the fuel tank being blocked somehow. When troubleshooting a used car which you just bought, I'd recommend looking at the sparkplugs, running a compression while they're out, and replacing them if they're worn or fouled. Replace the gas if the car might have been sitting for a long time or you're unsure of the quality of the fuel. Replace fuel filter unless it looks new, replace plug and coil wires if they look really old, ohmeter test for opens if they look OK. Inspect cap & rotor for cracks, arcing, wear. Hold air filter element up to light, if you can see light through it it's probably not the culprit. Disconnect the large hose between AFM and air cleaner and move the flap through its range with your finger to assure it isn't sticking. Test TPS and cyl head temp sensor with ohmeter. Set ignition timing. Now you are ready to troubleshoot the problem (unless you found it already by doing above steps). DAW

My post was rude and obnoxious and I appologize. I've been helped greatly by the wealth of knowledge and experience by members of this site and I too devote a generous amount of time in the interest of trying to help others. I think this site is great and has avoided some pitfalls that other such enthusiast sites fall into by losing the focus of the mission. I personally love the challenge of troubleshooting but I feel that for a bone stock 280ZX (no info that it's not), purchasing and perusing a Haynes manual should be a minimal requirement before a query to Datsun L6 Performance Board is made. So, sorry for spewing and overeacting but it seems to me that such general questions about stock passenger cars belong in another board and when any of us post, we have an obligation to include as much detail and history as possible in the interest of efficiency in diagnosing a problem. Mea culpa. DAW

Layton, that was an excellent description of what's going on but it's a bit baffling...sounds like too lean with the stumble and backfire; yet too rich with the fuel spilling over. I agree with Ruben re knowing your fuel pressure. Get a regulator and go for about 3.5 to 4lbs, timing and condition of ignition system is critical re throttle response. Get your main jet requirements sorted out (WOT) then tune down from there. DAW

Y'know, I'm sorry but you are either at the wrong address (try Zcar.com) or you are ill-prepared to ask your question. Set your valves, replace your plugs with platinums, replace your cap & rotor with the best brass contact items available, the best plug wires, check all your injector, ECU, sensors, and AFM electrical connections, replace your air and fuel filters, use gas treatment and a fresh tank of premium gas...then re-ask your question. I'm sorry, but this forum is not a baby-sitting service, it is a place for those who have already paid some basic dues about troubleshooting their cars and making them run strong; not barely run. DAW

I haven't done this, so I'm guessing at an approach...forget about removing a fender to install some hoodpins...try removing the flat rubber plug next to the factory hood leveler post (it looks about hood pin dia. size) and weld, or have welded) a nut with the same thread as the hood pin onto the surface. Thread your hood pin into this nut and use a jamnut to secure your adjusted ht. Use rubber spacers (like sway bar end bushings, e.g.) stacked on the pin to set the desired hood lift/gap. You could fabricate an alternate (longer) hood clasp loop to use with the lifted hood to provide a more stable hood at speed. DAW

Regarding the valve springs, I've looked at the specs for springs on the L4/L6, VG30, and Z series 4cyls (Z20/22/24). The inner springs are about equal on L and VG30s, and stronger than Z series. The outer springs are strongest on VG30, then Z series, then L series, then the L24 Maxima (intakes). Some specs for outer valve springs: Spring test Assembled ht. L4/6 108lbs@1.161" 1.575"@21.3lbs Z 4cyl 115.5lbs@1.18" 1.575"@23.0lbs VG30 117.7lbs@1.18" 1.575"@25.5lbs LD28 115.3lbs@1.18" 1.575"@23.0lbs L24Max 105.2lbs@1.18" 1.575"@? Assuming the springs are the same diameters and interchangeable, you may be able to exchange your outer valve springs for some from either a VG30 or a Z20/22/24 to use with your moderate cam and not have to buy an aftermarket set of springs. Has anyone else tried this? DAW

Check out the over-the-valvecover cooling fan on the L28ET...looks like a small electric turbo...if one of these were installed up front with its own little air filter and the outlet oriented so that it angled into the main airflow stream, could it have a pulling effect on the main column of air upsteam of it? DAW

You're right Dan, I forgot about the changes to the E88 related to emissions regs and the use on L26s (larger exhaust valve used with bore-notched block). The first Zcar I owned (still own) was an early '72 (8mm rod bolts). It was reportedly completely stock but it was always quicker than other stock 240Zs and tended to ping a bit more. When I replaced the engine I pulled the E88 head off and was surprised to find a smaller chamber that looked more like an E31 than any other E88 I'd seen. DAW

By old guys with hats I mean OLD, like 80-ish and older. BTW, why can't they and the group with the cell phones to their ears gabbing, barely driving, do this when they don't affect others? It would be fine if they were out in the country hitting trees; in fact it would be "thinning the herd." DAW

The E88 head is probably because he wanted to end up with 40cc combustion chambers (P90 is 53.6cc), plus with the throttle bodies he doesn't need either the notch in the intake ports, nor the 10mm hole between/above the intake ports. BTW, there are two E88 heads, the most common one has 44.7cc chambers but there is a rare early one that has 42.5cc chambers and looks more like an E31 chamber. DAW

Thanks Owen, I thought it looked too simple a solution but I hadn't bought any yet. I see they have a halogen bulb replacement for back-up lights, could these be used in an 1156-type socket for brake lights? DAW

Maybe the girl in the bank asking if April was in the Fall was from South Africa. Has anyone noticed that there is a definite category of bad drivers made up of older men with hats? I swear it's something to do with the hats. DAW

You didn't mention if this was an e-bay transaction. If it was, then you can offer him a deal: either you get a refund for the bad pump or he gets the worst Negative Feedback Comment he's ever had (then get a few friends to purchase pumps, send Negative comments even if their purchase is OK, and shut his e-bay business down). Pay-Pal has some means available to deal with bad transactions also, but as mentioned above there are time limits. If you can even the score easily, fine; otherwise get back what you can and walk away. DAW

I agree, with a factory bolt-on f.i. and ECCS setup available why use a carb for a turbo? You could do the triple sidedraft (6 throttle plates) approach by using f.i. throttle bodies on a triple manifold with a plenum (or weld injector bungs onto the manifold and alter the triple carbs by removing the venturies and epoxy-shutting the feed holes in the carb barrels to make them function as throttle bodies). The benefit of the mutiple throttle plates would be in great throttle response but overall, for a street-driven car it's probably not worth the hassle vs a stock f.i. setup. DAW

RE: LED tailight bulbs, J.C. Whitney still sends me catalogs ever since I ordered something before I had a driver's license and in the most recent issue they have LED-cluster tailight bulbs that appear to be replacements for a std 1157-type bulb. It looks like it would be a good thing, anyone tried them7 DAW

Sounds like it was damaged during the packing, prior to the shipping. It may well be an honest mistake, maybe he has someone helping with the packing. Regardless, it's the seller's responsibility to make it good...I'd take the $90 and be done with it; just write it off as a bad experience, otherwise it will eat you up and consume way too much time & energy. DAW

If nothing else, the m/t cars have 3.90s or 4.11s (R200), the diff and the trans are probably worth $300. DAW

The L28ET has vacuum modulators and the assy may have a reservoir (canister) function as well, the 280ZX does have a vacuum pump and tank (both na and turbos) but it's for the cruise control. It's located on the rt forward fender well. It could probably be adapted for supplementary vacuum for other uses. The LD28 has a serious vacuum pump built into the back of the alternator and gets its own oil supply and drain to the pan. DAW