datsunlover Posted August 31, 2005 Share Posted August 31, 2005 Ok.. given the insane gas prices lately, and the fact that it's going to get even MORE insane very shortly, I'm faced with two options as I see it. Take the Z off the road, or convert it back to FI to regain SOME milage, and hopefully save a bit of $$. Currently, I'm running a fairly stock L28 with a slightly shaved head, 510/280 cam and SU carbs. It will only run on premium. (I tried mid grade, it didn't like it at all) It also likes to suck it back at an alarming rate, partially because I have to run it fairly rich. It seams that the stock SU's just can't cut it with this cam, and If I don't run it rich on the bottom end, it falls on it's face at higher RPMs due to starvation. Runs WOT like a champ, but that's hard to do in town a lot.. ANYway.. here's my idea; I have a 92 pathfinder in my back yard that I bought for parts. (power optioned doors and front fenders are going on my 93 king cab, maybe the brakes too as they were just changed, spare driveshafts, ect)) It has a 3.0l V6 with a snaped timing belt. I got to thinking.. hell, it's all there, maybe I could take the 3.0L FI system and plop it into the Z! I still have the stock 280z FI intake manifold and fuel pump.. and considering I just wired up a GM tbi motor in a mazda rx7, I can't see how hard it would be to go Nissan to Nissan.. (yah I know, bitch about gas prices then build a V8 hot rod.. but that thing will run on regular, and IMO, in a light car, even the stock tbi 350 is overkill on 'power required' for a fun street car. ) My question isn't really 'can it be done' (because I KNOW I can do it)... but, would it work? I was told when I bought the cam that the 280z FI would not like it, and become.. confuesd. I didn't care though, I had carbs. The pathfinder HAS to have a more updated FI system though, being almost 20 years newer.. I know some folks use the 300zx ecu/sensors/? on their L28 turbo's and that's esentialy the same system (3.0L VG engines) as a pathy or king cab.. But will it be able to 'handle' my L28? What say you guys? Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted August 31, 2005 Share Posted August 31, 2005 put bigger throttle body and port stock efi manifold and run megasquirt with wide band 02.then you will be the master of how much fuel is used.twm makes some throttle bodys that bolt where su's went.with megasquirt you would get more airflow that way.i messed around with oem 280zxt efi for years,it gets to the point of wasting time vs performance gain. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted August 31, 2005 Share Posted August 31, 2005 As long as there are no problems with the trucks EFI system I definately think you could use it... I'd think it'd be almost exactly the same as doing the Z31 ECU swap over to an L28ET? Gas mileage would DEFINATELY improve, even after I tuned my SU's on a w/b O2 the best mileage I EVER saw out of those carbs was 13 mpg. Plus you should get better power and driveability, once everything is set up right. About the cam... well yeah, with stock 280z efi, any significant mods do cause the car to move more air and the stock efi can't handle it. I had problems when I built up my motor on the stock ZX efi (that was before I put the drivetrain into the '72 and switched over to SU's), it would ping badly at WOT over 4000rpm. Otherwise it seemed to run fine though. Anyways I just installed an adjustable FPR and bumped fuel pressure a bit and the problem went away. So even if worse comes to worse you could probably do some small tweak like that or maybe even get the ECU reprogrammed if you run into any major problems, but I would think it would work fine, since that efi is already from a larger and more powerful motor. Quote Link to comment Share on other sites More sharing options...
PeterZ Posted August 31, 2005 Share Posted August 31, 2005 The stock intake runner on a 208 is smaller than the port in the head and probably won't like the amount of air your cam could deliver. If you stay with stock components you might be better off tuning the carbs to be leaner on cruise and richer at full throttle. Changing the profile on tapered needles is fun and easy if you have done them before. You'll definitely get better mileage and not have the engine run-on (with the key off) with properly set mixtures in the idle/part throttle range while enjoying the cam at the high end. Quote Link to comment Share on other sites More sharing options...
datsunlover Posted September 1, 2005 Author Share Posted September 1, 2005 Funny, 3 replys and 3 of 3 posible replys I figured I'd get. Megasquirt; Cool and very tunable, but I don't have it.. I'd have to shell out cash, AND make a new harness, ect ect. I already have the pathy, and the previous owner was driving it problem free until 2 weeks ago when the belt snaped. I'm pretty sure the system is in good shape. Heck, the cap and rotor were in better shape than my daily driver pickup! (I really gota do a tune up on that thing...) SU's; well, they are easy enough to tune, this is true.. but mine are getting to the point of needing overhauling, AND I still say they just arn't adequate for my motor anymore. To start buying/fiddleing/sanding needles and boring them out, re-bushing them, ect will also require me to spend money.. From what I can see, all I'd have to do is weld a bung into my exhast for the 02 sensor, and modify the z intake to accept the VG throttle body/injectors, sensors. The rest would be 'plug and play' really.. I just don't know if the VG ecu is going to be able to 'adjust' to my L28's needs.. but I assume that it has a better chance than the stock 280 FI. Heck, that didn't even work right when the engine was stock! Quote Link to comment Share on other sites More sharing options...
Here comes trouble Posted September 1, 2005 Share Posted September 1, 2005 Go for it D L ! Your first benefit will be immediate gas savings while the car is idle while you are working on it. (LOL) Somthing like this modification is beyond my understanding but your posts indicate that you can make this a reality. Quote Link to comment Share on other sites More sharing options...
Bernardd Posted September 1, 2005 Share Posted September 1, 2005 What kind of CAS does the Pathy have? I would think that the biggest problem would be fitting it to the NA distributor. You may have to pickup a turbo distributor and oil pump. Other than that it should work the same as the z31 efi setup. Does that ecu support consult? You'd have all kinds of goodies and options available for it if it does. Quote Link to comment Share on other sites More sharing options...
datsunlover Posted September 2, 2005 Author Share Posted September 2, 2005 What kind of CAS does the Pathy have? I would think that the biggest problem would be fitting it to the NA distributor. You may have to pickup a turbo distributor and oil pump. Other than that it should work the same as the z31 efi setup. Does that ecu support consult? You'd have all kinds of goodies and options available for it if it does. Consult? Pardon my ignorance, but I have no idea what that is.. I assume it to be some sort of data link/programing tool similar to LS1-edit? I have yet to look at the dizzy very close, but I assume it to be similar if not identical to the Z31 units.. As for the oil pump, I thought they were all the same (the turbo being a higher flow model) and IIRC I already HAVE a high volume oil pump installed during the recent engine re-build... Quote Link to comment Share on other sites More sharing options...
AK-Z Posted September 2, 2005 Share Posted September 2, 2005 Its not really the oil pump that you need, but the shaft that drives the oilpump and the distributor. the 82-83 turbo dizzy has a different type of connection to the shaft. I can post pics of the differences. the 81 turbo, I beleive cand fit but it also has a vacuum advance. the reason why you would need a 82-83 dizzy OR a z31 chopper wheel is because the 92 ecu needs a crank angle sensor. As for trying to do ii, I so go for it! Quote Link to comment Share on other sites More sharing options...
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