russ in va

I installed the adjustable FPR (not RR, just adjustable). I now have 30 psi at idle (with the vac line hooked up), 40 psi with it unplugged (same as key on, engine off, pump running), 50-51 at full boost (with boost controller set to make 10lbs of boost). But, I just sold/traded the car to a friend of mine and his plan is to pull the turbo/injection off and put S/U's on it! It will sound much better (which is why he's doing it) but I'm loving the 200 lbs-ft of torque it makes now, he's going to lose ... what about 70 of that? Hmph. So I need to do some searching for him, but can anyone tell me off the top of their head, does my turbo motor make less compression than an N/A because it has dished pistons, larger combustion chambers or both? He has an old E88 (late 240) head with a set of 280Z valves to bolt on, but I'm not sure that's going to get his compression back up to "normal". Not really my problem but I'd like to help him in his quest if I can. (He really wants a set of ITB's he can run with MegaSquirt, but that's a whole different search he needs to do.)

Tim, that's a good point. My AFR is tracking in the 13 to 13.5 to 1 range from 2k rpms to 4500, then it creeps up steadily crossing 14:1 just under 5000 rpms and touches 14.5:1 at 5500 where I let off fearing potential damage. Max power on the dynojet is 162rwhp at 5k, with max torque of 188 ft-lbs occuring at 4300. The plugs all look good and the same, but I don't know if you would be able to tell by a plug inspection that an injector was a little off. BTW, these numbers are with a 2.5" mandrel bent exhaust and straight through core 2.5" magnaflow muffler. With an open downpipe (2.5 mandrel as well) and no other changes it made 174 hp and 196 lbs-ft (I have to admit that outdoor ambient temp was about 20 cooler on that run, though the temp in the shop according to the dynojet's thermo was only a couple of degrees lower. Of course these are all SAE corrected numbers anyhow so hypothetically it should not matter ... but it is forced induction.) I used to call BS on the notion that it was important to have 3" exhaust. Now I'm a believer, too bad I already spent the money on the 2.5" cause it's going to have to stay a while 'till I'm ready to spend the money to redo it.

BTW, the MSD 2222 is the adjustable FPR that I am planning to buy. The MSD 2225 is a fuel pump. If I were'nt so impatient, I would have gotten an aftermarket pump (MSD or Walbro), but again I don't think my new generic pump is the problem since it will make 75 psi with the return line clamped off. I just want to get the pressures to meet the stock settings to get my AFR's in line so I can turn up the boost!

Thanks for all the info. It is the pump they specified for the turbo ... but they specify the same pump for the n/a motor (and for EVERY other Nissan made that year). It's a generic thing. But I don't believe the flow rate of my pump is my problem. We are talking about fuel pressure being too low at idle as well as everywhere else. When the car is under load I don't have a problem with pressure falling off (which is what it would do if the pump was not keeping up), it's just too low all the time. The AFM may well be out of adjustment, but before I mess with it I wanted to get my fuel pressures right (as per the FSM). I'm going to try the adjustable FPR and see what that does, then I'll try messing with the AFM if need be. If Tim's numbers work out though, and 3psi makes a half point change in my AFR, then I may just turn the pressure up a scosh beyond the factory spec and get everything where I want it that way. I've got a boost controller ready to go in place and bump the boost up to 10psi as soon as I get this sorted out so I'm getting kind of impatient!

My '70 240 is powered by a stock l28et (83 style). It was running lean throughout the rev range on the dyno, so I checked the fuel pressure. Testing results before changing any parts: - Key on pump running engine off = 35 psi (should be 38-40) - At idle = 27 psi (s/b 30-32) - Throttle tip in = 33/34 psi (s/b 37) - At 7psi boost = 40 psi (s/b 47) - At idle with return line clamped off = 44 psi initially, dropping to 42ish (s/b ??? 60 ???) Installed new autozone pump: - all test results the same EXCEPT with return line clamped it now holds 75psi Installed new autozone stock replacemet FPR: - no changes at all Any ideas why all my results are coming back 3 to 7 psi below spec? Note: All these results were using a homedepot psi gauge. I subbed in a Snap On gauge I borrowed from a friend and the readings were about 1 psi higher, but still below spec. I am using the stock fuel supply and return hard lines. Barring any other solution, I'm planning to by an MSD adjustable boost referenced FPR (not a rising rate FPR or FMU if you will) just to try to get the car to work as designed. I can get an MSD part # 2222 for $72 at Autozone. Thoughts will be greatly appreciated.

I'll throw in my 2 cents on fitment. I have these wheels in a 16x8 with 10mm offset. My car is (unfortunately) at stock ride height. When I test fit a set of 245/45/16's, the front sidewall was in sligth contact with the spring perch. The rear would have fit except for some contact with the body work in a severe bump. If I had coilovers and the car was low, the front would have been fine (cut off stock spring perch and using 2.5" ID springs). In the rear, significant fender rolling and possibly stretching would have been involved. I am running 225/50/16's instead. I had to massage the stock spring perch with a sledge (you could say I smashed the spring perch flat where it would otherwise have been hitting the tire). Works great. I've been meaning to refit the 245/45's with the spring perch shaped the way it is now, I suspect they would fit. With the 225's I have no problem in the rear, but if the car was really low it might require fender rolling. If you go with 17x8.5 +4's and run a 245/40/17, I expect the front will fit fine (have a hammer handy to beat on the spring perch if neccessary). If the car is stock ride height, the rear will probably be fine too, but if the car is low or you drive on rough roads you will need to roll the fenders and possibly stretch them a bit.

If 225 is wide enough for you, you can't really get any more tire selection than what is available in 225/50/16. For that matter, there is a pretty good selection of 245/45's available too ... just check tirerack or edgeracing.com.

I know the 81's had the CAS down on the crank pulley while the 82 and 83 had the CAS in the distributor. I'm not aware of any other differences. At any rate, I know my distributor does have the CAS in it. I don't know what year my ECU is from as the part no. does not appear on the ECU part number list I have. Do you know what year the ECU you loaned me is from?

The wheels will not be back on the car until my tires come in the middle of next week. I'll definitely post back up with MUCH better pics once they are on the car. Thanks! Russ

Dave, thanks for the input. And thank you for your generousity with the ECU loan! I replaced the coil itself (the old one was leaking oil), but not the power transistor. I had ordered a coil from the local import autopart store, but when it came in it was a coil only ... and made in China. They had a Bosch blue coil on the shelf, so I got that instead for the same money. I did not think this could effect timing advance so I had not mentioned it. Do you agree? No, I don't know if the car was ever getting advance. So this problem could date to the time of the swap 6 or 8 years and 2 owners ago, or it could be recent. At this point I should problable bring up some info I originally posted in another thread. The day I bought the car, it ran pretty well (about like it does now). A couple of days later, it lost all power. Actually dynoed it and it made 85 RWHP. On Dave's advice, I checked the timing and found base set at about 0 degrees. I twisted the distributor to full advance and got about 20 degrees. Car now runs like it did when I got it. I'm now begining to think these problems are related .... but I have no idea how? When I did my diagnostics, I did check everything at the harness under the dash. Note: The CHTS testing did not check out per the FSM, I'll paste those results in here now from post #7 above in italics for easy reference ... could this be the problem? And what's the right way to fix it? -Cylinder Head Temperature Sensor - fails the factory test but I'm puzzled (note: infared pyrometer reading at CHTS = 95 degrees F at the time of these tests) -pin 23 to body ground is infinite resistance (shoud be less than 2.9 K ohms at 68 F or above per FSM) -BUT (this is not a factory test, I just looked at the wiring diagram and figured out where the other lead from the CHTS hooks up) pin 23 and 26 together read 1.237 K Ohm (why doesn't the FSM have you take this reading instead of the 23 to body ground reading?) -Reading right off the sensor itself was 1.240 K ohm -Also, if you unplug the CHTS with the engine at full operating temp and running, it misses badly BUT there is not a noticable spike on the dyno's wide band 02 sniffer?? (does this sound normal?) The only other bothersome result from my probing was the ground/air regulator wire at pin #108 (see post #7 for details). Can I just run a new wire to fix this? I'll have to try the listening techinque to be sure, but since the air fuel stays in line on the dyno, I'd certainly expect the injectors are firing in the right time. I would not think they could supply enough fuel at 800 cycles per minute (idle speed) to feed the motor when it's running 5000 rpms and makeing 150 hp. Doesn't the fact that the car runs and revs up at all indicate that the ECU knows the right RPMS and is sending spark signals? Just trying to think this through.

18racing.com sells rota's they have the RB (looks similar to a panasport) to fit Z's with proper offset

OK, I installed the known-to-be-good ECCS that Dave lent me (THANKS DAVE!) and found no change ... I still get no advance as I bring the revs up. Rats!!! What now? I'm at a loss. Based on the knowledge that Bernardd shared about the TPS signal triggering the ECCS to not advance, I'm going to triple check the TPS, though I already did. Any other suggestions? I'm trying to get this straight in my head. On an old school dizzy, when the weights spin and crank in the advance they make the point plate turn. But since the ECCS is doing the job of the points and the advance plate with computer magic, there are no moving parts like this in my dist, right? So since it's not the ECCS itself, that MUST mean that some input into the ECCS is causing this, right? Other than the TPS, what could possible do this? My ignorance is killing me!

They are gunmetal. Details here: http://forums.hybridz.org/showpost.php?p=803536&postcount=91

No, the 10mm pulls them into the car relative to the zero offset that most people seem to think is correct for the car. I got them from 18racing.com. Thanks for the compliment, I know I love them!

Armand, thanks for the kind words! These are the perfect wheels for a Z as far as I am concerned and I am thrilled to have them. They look very similar to Panasports, but I actually like them better (the color helps!). I need to weigh them before I mount the 225's, I'll guess about 17lbs but I want to know myself so I'll get back to you. I believe that 245/45's would fit on the rear with fender rolling, it might require some fender stretching but that will likely vary from car to car. The lip I'll have to measure, but I'd guess it's between 2.5 and 3". I got mine from 18racing.com. There is a group buy going on these wheels on this board in 17" sizes. So far I don't think the 17's actually exist, but they are supposed to be coming. I'll post more pics once the tires come in.