GrayZee

It will run without the condenser. Not sure, but I think it's only purpose is to silence the electrical noise that you would pick up through your radio.

No, the O2 sensor feedback and diagnosis on that ecu was disabled last year. I do have a new theory on what the problem is however. I took it for another drive and noticed that the problem really has nothing to do with boost. The engine falls on it's face at full throttle. I was at a very slow roll and put it to the boards and it did the same thing once the throttle went all the way down, even with no boost. This lead me to believe that I had issues with the TPS. I had a 240sx TB that I was gonna bolt on but gave up on the idea as that that TB plate actually rotates the opposite way that a Pathfinder TB does. It can be done but the throttle cable has to be mounted at a goofy angle, I did not think it was worth the trouble as the 60mm isn't THAT much bigger than a Pathy throttle. Anyway, getting back to my theory.. I believe that because the Pathy throttle is moving opposite compared to a sx or z31 TB that the off idle indicator is coming on at full throttle rather than off idle. I am told if this is true, the ecu will go into idle mode and release control of the timing and fuel maps, and goes to a preset idle program. This would certainly make the engine fall flat on it's face. To fix this, all I have to do is flip the outer wires on the TPS plug around. I'll give'er a go tomorrow hopefully.

Ok, I took it out for a drive again. This time I hooked up a fuel pressure gauge by the windshield. It was reading 38psi under full throttle and at 5psi. I guess the fuel pump is not the problem. I am using a 21 year old wiring harness to run the engine, I am wondering if there are some gremlins making a home of my harness? I guess next step is to get it on a wideband and laptop to see what it is doing. *SIGH* how come it never works 100% the first time around??

Yes, the engine starts, warms up and idles fine. My ecu is a 89 z31 that has been re-tuned. The ecu was working in my L28et with 480cc injectors just fine, so I can't see the tune being that far out with the Vg30et. The fuel pressure regulator is from a turbo z31. I guess the only components that are from a n/a vehicle is the upper manifold, including fast idle controller, pcv valve, ect. I'm not using the AAC or EGR valves. I found out that a Pathfinder does not use a fuel pump modulator, but I still suspect fuel pressure drop. Is is possible that a fuel pump designed for use with a TB unit is that much weaker than multiport? I can't really see it being that weak, but I guess you never know.. I guess I'll have to figure a way of mounting a gauge against the window so I can see what's going on.

Well I took the turbo Pathfinder on it's maiden voyage today. Hit about 5psi but only if I accelerated very slowly. If I hit the go pedal really fast the engine would fall flat on it's face when the boost gauge hit zero. It felt like it was starving for gas. Making me question a couple of things... I decided to keep the stock fuel pump for the time being figuring that it must be fairly similar to the z31 pump. Would a pump designed to feed a 140hp Pathy engine really run that lean on the Vg30et on low boost? I have wired up a few turbo swaps and never bothered with the fuel pump modulator. I understand that it simply limits the voltage to the fuel pump to run quieter in low load situations. Is it possible that my Pathfinder also has a modulator somewhere and is making the pump run at low voltage? (low of course being the default position I'm assuming) I am using the original Pathfinder fuel pump relay and just ran my z31 engine harness to trigger the relay. Perhaps now that my original ecu is no longer hooked up or functional there is nothing telling the modulator to increase voltage? Any thoughts? I wish I had a good Pathfinder wiring scematic.

At the time I first started playing with the water injection I was using the stock 260cc injectors, and as for timing.. I can't remember at the moment, I know it was advanced off the scale of the crank pulley. That was with a stock 84 turbo ecu. With the help of the ackly nozzles I was still able to keep it from running lean even with the small injectors. 10 or 12 to 1 at full boost if I recall correctly.

or put flattop L28 pistons in your L28et

I was thinking.. people have had various get togethers around the country but it is usually localised within a few hundred miles as most people either don't have time or wouldn't want to drive their Z that far. I was thinking.. what about a get together without the cars, somewhere touristy where flights would be cheap (like Mexico or Vegas) just a thought.. would anyone be interested?

Hasn't this been discussed 100 times already?

This might be off topic but one thing you should make sure of is that your starting circuit uses a starter relay. The old Datsun ignition switches had a wire that simply goes to the starter terminal. It's been my experience that the Datsun switches do not like the extra current that the Chevy starter soleniod draws.

Buy a engine gasket kit for a L28et and take it apart. With the head and oil pan off you will be able to see alot more. If for nothing else, having the head/manifolds/oil pan off will give you the chance to clean it all up nicely.

Yeah that's right.. the Vg30et has the left engine mount wayy up towards the front of the engine to make room for the turbo. The alternator is also relocated to the other side, below the PS pump. Nothing seems to come easy when it comes to those z31/vg30's *sigh*

Interesting.. so you are saying that the regular P90 allows higher revs? How much higher? I can't see it being much.. The L28et seems to get its power from torque at lower rpms.

What was I thinking.. no, the z31 turbo manifolds definatly will NOT fit. They may bolt to the engine, but the z31 uses a crossover that wraps around the rear of the cylinder heads. The Pathfinder engine is mounted way to close to the firewall to allow clearance for that. This is why I made a custom crossover that goes under and around the transmission. Not the best setup, but space is very limited.

I have no idea if those manifolds will bolt on to a 3.3 liter engine, however I can tell you that even if they do you will have a quite a large list of other things to deal with. One of them being no room for the turbocharger. I am almost done with my turbo Pathfinder project and it's been a long road. PM me if you wanted some details. Feel free to check out the pics: http://www.members.shaw.ca/icecube/PathyPipes/ Notice that those are NOT stock z31 manifolds!

What do you mean you checked for voltage at the injectors? The pulses from the ecu come in the form of a - ground to the injectors. The injector plugs should have 12v+ at all times. It is connected directly to the battery via a fuseable link. If you do not have the 12v+ I would check your links/connections.

It depends on how much power you plan on running. Alot of people assume that with a numerically high diff ratio you will go faster. Well that may be true sometimes, but not always. A L24 with 120hp might benefit from a 3:90 or 4:11 ratio, but a L28et with 250+hp and gobs more torque would take those gears and spin up to redline in the blink of a eye. You would spend more time shifting gears than anything. A engine with alot of power benefits from a steeper gear ratio that allows it to WORK. I have a L28et with a 3:54 ratio diff and a 83n/a tranny. I find the ratio works quite well, but I wouldn't mind trying a 3:36 rear end (if I could find one) Right now, I have to shift into 4th before I cross the quarter mile, it would be better if I could just leave it in 3rd I think. Plus the steeper gears would make it harder to spin out the tires. When choosing a set of gears always consider the OVERALL ratio. For example.. a 79zx with the early tranny and 3:54 diff has basically the same overall ratio as a 83zx with the late tranny and a 3:90 diff. Steep tranny and low diff or steep diff and low tranny. Basically 6 of one and half a dozen of the other. Check out all the possible gear ratios here: http://www.geocities.com/z_design_studio/

The people that are driving z31's don't even have to do the z31/maf upgrade (they already have it stock obviously) All they need to do for 300hp is to get a re-tuned 87-89 z31 ecu and you're all set! M1cheal, what year is your car?

Hey no problem, that's what this site is for

a 83zxt "MAY" have a T5 Borg-Warner trans, which is a totally different animal. However there are probably alot of aftermarket options for that tranny.

There are only two wires that go to the HEI. (other than the 3 that go from the base to the cap) Of the two, one is to power the HEI unit and has 12+ when the ignition switch is turned to "ON" You can easily check for that with a test light. The remaining wire is the one that goes to your tachometer.

Are you calling me old? Speak for yourself! LOL

I agree, sounds like accelerator pump to me. There should be a adjustment for that.