killersqrl

The search feature on this forum seems to be hating me right now - I searched this thread for 'iridium' and also for 'spark plug' and it said no hits on either. Which is a lie because I remember people talking about which plugs they ran with the swap. The reason I want to find the info is there is a deal on the ngk iridiums right now and I want to get a set or 2 to have on hand:
http://slickdeals.net/f/7842571-ngk-...n-store-pickup

So if anyone can chime in with what seems to work the best, please do. I'll be na-t, 550s and tt hg when I put in the new plugs.

aznexus

Ali_Sc3 recommends BKR6EIX or BKR7EIX.

I'm running the BKR6EIX on 550cc injectors on m NA-T with no problems. No TT HG installed yet.

187

Now that I'm running the vpc can I try my old cap and just hold the power steering and PCV hose?

This misfire thing is ridiculous, I'm really suspicious of the tps but nothing seems to be working. I moved the 02 sensor up higher in my downpipe. Should I try moving it the the closest bung to the turbo(4" away) ? Also I'm still chasing the P1658 after I just installed a 25 ohm resistor.

And I need to get the car inspected this month so it's pretty much a mad dash.

Ali SC3

iTrader: (10)

safc is actually much simpler for injector changes, its just when you try and tune with it that things get funny I have heard. the seasonal thing happens to me also, that is why I do like to have boost cut somewhere around 20 psi and its nice with the map ecu you can set it to whatever psi you want. I leave it at 20 even though I might be running off the gate at 11 or somewhere around 17-18 if I have it turned up. sometimes when the weather changes it will just hit boost cut and I know I have to go out and adjust it some. part of the issue of a manual boost controller but I like it its more predictable even with the weather changes.

I have tuned the aem to do full electronic boost control on my car before, man that was a bit compicated but it did always home into the right value despite season, but you could feel it jumping up and down a psi or so trying to get it right, the manual one just goes to where you want it and it holds, I prefer manual 9 out of 10 times, I can go turn the ****, you will find it a normal procedure in the future like changing your oil =)

also a good thing trick is to tune for 4th gear, and then for when the boost comes on faster tune the lower loads for 3rd gear. leave it a little rich and 2nd will be fine as well. it seems the afr's get a touch leaner in boost as you go up gears so have 4th nice and rich which is what the stock ecu does anyways.

yeah thats the only issue with the mk3 trans is the shift feel. the 350 is supossed to be nice and smooth I might be working on a new shifter setup for that trans I will keep you all posted in the 350z trans swap thread when I figure it out, I want to make it 2" shorter than the shortest current version you can buy. I dont plan to sell anything either it will be a DIY.

sounds like a lot of fun. these days with e85 bringing up the rating you can probably get away with that, just give the motor some time to cool between pulls and go to a colder plug in the 7 range.

probably bkr7eix if you are going over 14 psi. bkr6eix if you are staying under. Its not an exact science though I have had the 6 in there for years and I go over 14 psi all the time.
But if you are consistenyly running higher boost pressure then its helpfull to have a colder plug like a 7 or if you are at 20+psi just go ahead and drop to an 8 range plug.
Colder is typically better for boost to reduce chance of pre-ignition from the plug getting too hot, but if you go too cold, then the car will have trouble starting and keeping the plug hot enough to stay clean when out of boost = a fouled plug.

for reference our stock plug is a 5 range, a stock TT plug is a 6 range, most people on single turbo under 20 psi run the 6 or 7 range (more a preference thing here but common sense says 6 under 1 bar and 7 over 1 bar), higher power builds you are on a 8 plug and should really already know exactly what plug you need by the time you get to this level of power.

Yup you got it that is correct.

Yeah, you can just stick a breather on the valve cover for the hose coming from the passenger valve cover (the pcv is on drivers side). for the PS hoses, I removed both of those a long time ago, if you have the rpm's bumped up some you do not need it. when doing hardcore parallel parking just tap the gas if the rpms are dipping, I have never had it shut off on me ever from that.

I run my o2 sensor for the ecu in the closest bung to the turbo, make sure there is no leak at the turbo to downpipe. when its cold and you just start it, run your hand over all the seams, if you feel exhaust pulses or it sucking in air then it will throw off the o2 sensor as well. its a tricky gasket to get in there and clamped down, I do it 2-3 times every time I put that v band clamp on to get it to not leak, def check that out and move the o2 to the closest one. wideband on the second closest is fine, its very sensitive anyways. I don't know anymore about the codes but I thought the misfire went away? still there? that is really frustrating I am sure to say the least.

187

Well the p1658 is still coming up. I tried 1k before, now I have the 25 ohm and its no good. I figure I'll try an even higher one just to see because I'm out of options.

I'll give the old cap a try tomorrow and I'm going to try and bump my timing up a little closer to 10.

I don't currently have a gasket between the turbo and downpipe so I guess I'll make one tomorrow.

As far as the misfires go I'm going to tinker with the tps if the stuff mentioned above has no effect.

Ali SC3

iTrader: (10)

^^that is an interesting deal on the iridiums.

for the code, maybe try a potentiometer like a 10k volume **** and you can try it at various points.
no gasket, def check to see if its leaking or not hard to say.

187

Well I rewired the Wastegate vsv as well as the vsv that controls some valve that effects the iacv to battery power at the ecu. This was mainly for peace of mind after the other options failed. Used a 1 Mil ohm resistor on the wastegate vsv because why not and it worked. No more P1568 .

So atleast for now if I cant fix the cold start misfires I can reset the ecu when its warmed up and just hot start it and put miles on before I go to the inspection shop.

Edit: nvm p1658 came back after I passed my inspection. I'll have to go get another 1K to test this thing out among other things. The saga continues.

187

So hopefully someone can weigh in on this,

Start the car, car idles high around 1200rpm and the fueling is a little on the lean side. I check the short term fuel status and it was around 12-14%(+) at idle for a few minutes then shot up to 19-20 % maintaining the 1200 rpm. Then all of a sudden the trim drops and the rpms drops after about 10 minutes. The short term fuel then cycles around 0 as it should.

Based on what Ive read (not very much) the trim seems to be indicating a vacuum leak that goes away as the car warms up. symptoms include high idle, lean mixture and random misfires until the car warms up enough for the idle to drop.

I didn't want to start a new thread trying to explain the whole setup so I figured I would just post in here.

myLEXsc400

Yeah, mine is like that too. Goes lean on a cold start and idles high. When i give it a little gas it richens up to a safer level. Idle comes down when the engine warms up and the wideband shows normal at that point....

Also, what is the vsv that needs to be addessed? I just started driving the car again this year and really dont want to blow it up. It also backfires occasionally when i redline it in gear

myLEXsc400

btw, my car still misfires, and CEL is on. misfire is on all cylinders i believe

187

What kind of vacuum are you getting at idle?

Did you ever do anything with the tps? My cold start misfire seemed tps related but i can't improve on it because of the lean condition.


Also my temp sensor is having issues because once you plug 1.2k ohms into the MAF pins is reads only 800 ohms..... not sure how that works

SCereal

iTrader: (4)

Figured out issue.

SCereal

iTrader: (4)

Never mind figured it out.

187

Just to follow up on the whole temp sensor thing. I had to use 2k ohms to get 1.150k at the sensor.

This small change made a huge difference between the vpc and the computer. It still idles between 14.7-15.X but it holds the rpm alot better and that's all I got so far. I was considering pinning the maf back in but I think that may confuse the vpc based on the install guide. So I guess I'll get some more miles and report back for the obd2 ppl.

SCereal

iTrader: (4)

I had a really hard time finding any information on the 97+ cluster tach fix when doing this mod so here's the write up:

Here's what the back of the 97+ cluster looks like



The screws are not all the same so make sure you keep track of where they came from. Some are long, some are short, some have pins on the end of them, just be careful! Pull the two ribbon connectors up and that will release the ribbon cable. After pulling the rear cover off, here's what you see.



Remove the two screws on the upper PCB and very carefully remove it. There is a group of pins that go through the board into a black connector. Just be careful not to bend the pins. There are so two ribbon cables. Pull the connectors up to remove the cable.

The resistor you're looking for is R2. It's a big full size one near the orange connector. Here's the back side of the upper PCB with the jumper soldered in place.



"installation is the reverse of removal". Alternatively you can leave the upper PCB in place and just snip that resistor out anad jumper the front side. I chose to leave it in place since I had to remove the board anyway to trace down which resister was the one to jumper.

Put it all back together, being super careful of the pins and don't forget to put the last two ribbon cables back on before installing it in the car. Good to go.