Zmanco

From the Checker site showing where else it's used: http://shop.oreillyauto.com/ProductGuide.aspx?mfrcode=FRA&mfrpartnumber=G3829 Looks like it's also on 91-93 M5s as well as several big V8 Mercedes so I doubt flow will be an issue. Hopefully it's smaller than the Volvo... Thanks Drax, that's the kind of suggestion I was looking for.

Just push on rubber. I am looking for something more on the "affordable side", preferably something I can find at the local parts store. I was thinking of using the filter that's on my Volvo turbo (that engine is rated ~240 crank HP) and because I know its part number. But it's really big (bigger than a large soup can!), so was hoping someone found something smaller. That looks like it's only for -AN, and I'm sure is a sweet part, but probably also more than I wanted to spend for this.

Hmmm, you say you're not burning any oil - then I'd challenge that the oily spark plugs and low compression numbers are due to worn rings. I'd be looking at the valve guides and seals as you mentioned instead. You might want to rebuild the bottom end while you're at it, but I don't think that is the root cause of the issues you describe.

I've seen the stock turbo injectors spec'd at 265 and also 280 cc/min. In the end I gave up trying to resolve it as tuning the VE table compensates for it anyway.

You should be able to set up a good idle either way. But if you go with the resistors, you've eliminated one more variable (the PWM settings). FYI, I ran with the PWM for a while and had no issues getting a good idle due to the PWM setttings. But on my first day at the track towards the end of the longer sessions (more than 15 minutes) I had fuel cutouts while at sustained high revs and WOT. Datalogs didn't show any problems. Long story short, my theory is that the injector drivers were overheating and shutting down for a few seconds. I added the resistor pack and never had this happen again. I really wanted the PWM setup to work as it's more elegant from an engineering point of view, but I didn't want to waste any more track time either. It couldn't hurt to add the resistors and see if the idle issues go away ...

For those of you with early Zs (70-73) and upgraded engines, what are you using for a fuel filter? I've finished my turbo upgrade and obviously my max fuel flow is significantly more than before. At the moment I only have a small filter between the tank and the pump. I'm guessing that the early stock filter might be too much of a restriction at max flow. FYI, based on what others have dyno'd with a similar setup, I'm guessing power is around 275 whp right now. I'm hesitant to just experiment in that I'm worried about leaning out under boost and causing damage. FYI, I'm a little space limited in the front passenger corner of the engine bay where the hardline from the fuel pump comes out due to several relays for headlights (mounted on the fenderwall a long time ago before I ever thought I'd go turbo) as well as the intercooler piping. So smaller is better as long as it doesn't restrict flow. How small of a filter can be used and still provide good protection without too much restriction of flow? Fuel lines are 5/16". Anyone with part numbers?

Sorry I wasn't more clear - I didn't mean to say that no ports were blocked, rather that the holes in the gaskets were all in the same places for both. In other words, for every passage between the block and head, if the factory gasket had a hole, the Felpro did too. The engine I bought had been pulled from a stolen and wrecked 82 turbo with less than 100 miles. It had been stored for 27 years.

Pull off the distributor cap and rotor and look at what is mounted below. If you can see a set of points, then you (obviously) have them. I no longer run them so can't take a picture, but perhaps someone else can post one?

IIRC the DGVs have 2 venturies, but one of them is only opened when "floored" - in other words, like a secondary on a holley 4 barrel. It sounds like you are fine until the second venturi opens and then it falls flat. I don't think we can tell for sure if you're lean/rich from what you've said, but you might want to start by making sure that basics are all ok, such as that you have proper fuel levels in BOTH sides of the carbs, that the floats move properly, etc. Also check to be sure that the jets for the secondaries are installed and match. When I bought my DGVs used a long time ago they were in horrible condition and none of the jets were in the correct locations. They're pretty easy to rebuild and there's lots of documentation on the web about reassembling them (including diagrams) so it's not a hard project. This is only a guess, but I suspect you will find that there's something wrong with one or both of the secondaries.

You didn't say which block and head you are using. I just used a felpro and before installing compared it to the original factory turbo HG and there were no holes plugged. This was a P54 / P90 build. I've also used Felpro on several other L28 builds with N42 blocks and a variety of heads and never had a problem with a blocked water port. I believe there are 2 part numbers from Felpro for all the Zs now. I used the #8799 this last build which is spec'd for all Zs 81-83 both turbo and NA. There is another part for earlier, although I'm pretty sure I've always used the 8799 even with an N42 head on N42 block. I'm not pushing you towards Felpro, just suggesting that maybe you have something else going on here. Might be worth picking up the part number that you DIDN'T use last time and see if you're ok on the water ports.

This is a long shot, but are you running any of the ignition timing filters and/or masks with MS? I had experimented with a timing mask and forgot about it and then one day couldn't get a good idle. It felt like a misfire/no spark, but was inconsistent across the cylinders. I think the mask had been set a little too long to be safe for idle, and for some reason all of a sudden it began to cause issues. What if you set the idle higher, say around 1000 - 1100 rpm? What AFR is required for a good idle then? If that solves it, I'm thinking ignition, not fuel delivery. I can't help but wonder if the tank work is a red herring distracting you from an ignition issue. Sorry I can't offer anything more than that. But I'm following this because I seem to come across the same issues as you, usually a year or so later. Thanks for forging the way!

I once did a ring job on my L28 while it was in the car. At that time i didn't have an engine hoist so thought I was saving money. You can do it, but it's awkward and a bit back breaking leaning over the fender to break the glaze on the cylinders. Given that Harbor Freight often has hoists for about $100, I'd suggest you get one and pull the motor. The extra time spent is easily offset by how much easier it is to reassemble it on an engine stand. Plus you'll be surprise how many more times you'll use the hoist, especially if you make it habit of hanging around here BTW, except for the compression test and oily plugs, are you experiencing any other issues with the engine? How much oil does it burn in 1000 miles? Just suggesting that you might not want to bother until you're ready to do a proper rebuild. In my case, less than 10k miles later that's what I was doing.

Unless you have some really strange settings, After Start Enrichment and Warm Up Enrichment only operate below normal operating temps (180F) so there's no need to turn them off. I was just saying not to bother with fine tuning them until you have the base tune pretty close. I WAS suggesting you turn off the other features such as Over Run Fuel Cut, Accel Enrichment etc during tuning. To do that, you need to go to each feature and either turn it off, or put in an activation setting that will never be met (say MAP>100 for a NA engine). The key is to get a base tune at normal operating temps done first, and only then worry about tuning everything else. All those other features exist to compensate for special conditions where the base tune can't handle it. If you tune for the special conditions first, you'll never get the base tune right.

You had one too, although your wife did most of the work Congratulations and enjoy - it goes by so quickly!

Before you worry about cold start tuning, you need to have a decent tune for normal driving. Otherwise you'll be compensating for the incorrect warmed-up tune. Start by turning off all those fun bells and whistles such as MAT Correction Table, Over Run Fuel Cut, etc and just get the basic VE table (along with the Ign Advance and AFR Targets tables) reasonably close for street driving. I would even suggest turning off Accel Enrichment in the beginning. Only once you have the basics well sorted should you begin to add those other features. BTW, it only takes an hour or two using MLV to get reasonably close enough. Also, play around with the VE Delay in the MLV VE Analyzer tool. I've found that a setting of 8 for rpms below 3k and 3 for 3k and up works best, but it's entirely a function of your car. And yes, you will notice that there is no "8" setting - you have to edit the config file to get to that. If you don't want to mess with it, just set it at 4 and leave it. From there you can begin to focus on After Start Enrichment and Warmup Enrichment. In general, it's best to get a good baseline when warm, and then gradually work on one or two (at most) other features at a time.

I am and it's mounted a few inches in front of the radiator, not flush with it. I wonder if there is turbulence between the two which is reducing the airflow? TonyD, what you're saying is indeed in the back of my mind. I don't want to get too carried away with one datapoint that wasn't even obtained with any sort of real control. I was just throwing it out there to see if perhaps someone else had seen this and tracked it down. Right now the weather has cooled a lot and so it's hard to stress the cooling system without track time. I'm just driving it and since I'm not having any overheating issues, am not going to worry about until it warms up again. BTW, I am running a Nissan 180 t-stat. Just to be sure, I replaced it but there was no change.

Actually IIRC, I couldn't find any metric unions. Instead I found a metric to SAE adapter at NAPA and as I had to make my own hard line anyway, just bought an SAE line, cut one end to length, and used a metric fitting on one end instead.

Those pictures are from my 73 so I think you'll be on the right track. And I'll put another plug in to spend some time researching brake pad materials and choose based on how you plan to drive the car (daily driver vs. 1/4 mile vs. canyon carver/road course). Quality pads are going to make at least as much contribution to improving stopping distance and fade resistance as just bolting on hardware.

Measurement is via the stock sensor/gauge as well as megasquirt. The MS sensor is mounted in the factory turbo thermostat housing next to the factory sensor. They are pretty much in sync with each other. I thought that the temp swings were due to what you described as well so I tried an experiment where I routed the 5/6 hose to the water inlet on the passenger side of the block. I drove around like that for a few days and it didn't seem to be any different in terms of the temp swings and elevated temp. I will add that this was not a controlled test in that I just drove the car, not on the same routes or under the same conditions. But there was enough variety (city streets and highway) and the temps were similar enough that I think it was still a valid test.

I have the same setup as you if you're using 300zx rotors in the rear, but I find that unless I use a rear pad with a higher coefficient of friction than the front, even with the prop valve all the way open, I get front lockup first. While I don't see how the stock prop valve could cause the rears to lock first, still I'd remove it just to get one more variable out of the equation. Also, I would suggest you pay more attention to the pads you choose. My own limited experience is that the pad materials have MORE EFFECT on the overall brake performance than the calipers and rotors. If you don't know what brand of pads you have front and rear, then that could also be an issue, although if turn the rear pressure down with the prop valve, it should prevent the premature locking you describe. If that doesn't work, then I think you have to go back (again) and really confirm that you have the adjustable prop valve in the rear circuit and not the front.

You still haven't said if there is a problem you are trying to solve. Measuring the voltage across the coil (what you are doing) with the engine running really doesn't tell you anything. The actual voltage is changing constantly as the points open and close, but a voltmeter cannot respond that fast so it just averages it. The actual voltage you measure will depend on a variety of factors including the setting (dwell) of the points themselves. When you measure with the engine stopped but ignition on, you will get different readings depending if the engine stopped with the points open or closed. Unless you are experiencing a problem driving it, you haven't described anything wrong with your car. Just drive it and enjoy.

So I've got the motor up and running with the #5/#6 feeding into the bottom of the thermostat housing on my turbo motor. Unfortunately the motor is somewhat new to me (more in a moment) so I don't really have a baseline to compare, but I've noticed that the temps seem to swing up and down more than my old NA motor. The new motor has a P54 turbo stock bottom end (untouched), shaved P90 head carried over from the NA engine, Schneider turbo cam (2nd level), stock exhaust manifold and T3/T4 turbo with 3" exhaust. Basically the only new parts on the "new" engine are the block and internals, timing cover, thermostat housing, injectors, exhaust manifold and turbo. The head, water pump, thermostat, temp sensors, and intake manifold are all carried over from the old motor. As an experiment I tried routing the 5/6 coolant into the water return on the passenger side of block to see if the temp swings I'm seeing were more of an anomaly due to dumping hot water right where the sensors are located. Turns out it didn't make any difference that I could tell driven on the street, so I moved it back. The old block was an N42 which without the siamesed cylinder walls is said to have better cooling. The new block is a P54. Any thoughts why the temps are different with this motor even when driven with a light steady foot, such as cruising on the highway at 65 mph? Ex. old motor temps stayed pretty close to 180, maybe rising a few degrees on a warm day, but moving slowly and never more than 2 or 3 degrees at most. Now the standard cruising temp, even on a cool day, is 185-188 and the temps will sometimes surge up to 193-195. Again this is when cruising off boost with light throttle and steady highway speeds. Could the switch from N42 to P54 block be the reason? Oh, and I have not yet put the splash guard back on, but in the past it never made any measurable difference on the street.

How are you measuring the voltage? Are you putting the probes on both ends of the resistor? And is the engine running or stopped? I very much doubt that there is anything wrong with the resistor - it's hard to see how it could fail, much less 2 would fail. What it is the problem you are trying to solve? You didn't say why you suspect the resistor.

Very nice sound Phlebmaster. There's nothing like the sound of healthy NA straight 6. I'll add that I just had a 3" exhaust installed on my new turbo motor. Initially it was a straight pipe all the way back (stock exhaust manifold with T3/T4 and Schneider stage II cam), but it was so loud there was no way I could drive around my neighborhood without problems. We added a glass pack where the muffler would be as a temporary measure and it's actually pretty reasonable. But it doesn't sound anything like my old NA engine did Of course, it rips through the gears so much faster now that it's not too much of a sacrifice