madkiwi

I have been having pinging that puts my car into safety boost for a while- I will tell you what has been dealt with. I discovered the local Nissan dealer installed completely wrong plugs (PFR5G-11). Put in the right "cold" ones (PFR6B-11B) but that did not solve the detonation problems. I knew I had some serious boost leaks, I got the boost leak tester (with the pressure gauge and the Schrader valve) and was unable to get it to pressurize. Literally the air leaks out as fast as I pump it in. My mechanic smoke-tested, claims he could not find any leaks. I knew this was bs, so I took it to another shop. They found a leak from the vent hole on the LH recirc valve. A lot more smoke was coming from the area that could be explained by a 1.5 mm breather hole, but we could not see any other source. I decided to go over my vacuum lines very carefully, found a leak in the hose to the LH recirc valve (so not just a leak in the valve, but a leak in the vacuum hose to it). Replaced the recirc valve and the signal hose. I had been driving for a while with a faulty detonation sensor (code 34) and wondered if I had carbon buildup from running rich and with retarded timing over a long period (the sensor and both oxygen sensors were replaced August 2013) so I had the Motorvac treatment (top end and valve de-carboning) done recently. After all the fixes I took it out Friday and while boosting it went into safety mode. I actually watched the needle on my Autometer gauge drop from 11ish to 6. Not happy... I checked the timing after I got home. It was about 16-16.5 degrees. I reset it to 14.5-15 degrees. The timing was rock solid, no wiggling around (unlike my Pathfinder, which is all over the place). Brand new fuel filter- installed it at the beginning of August. Checked my CTS at the same time, my wife has no idea I was using the kitchen to boil water for dipping a dirty car part! It was all to spec. Today I hooked up my fuel pressure gauge and zip-tied it to the wiper, then went for a drive. When ignition was off- 40 psi every time (and stayed there for at least 30 minutes while I had lunch). Key on- jumped to 42 psi, then back to 40 when pump shut off. On and idling-vacuum gauge showing -15 inches- 36 psi fuel pressure Driving -10 inches- 37-38 psi -5 inches- 40 psi 0- 44 psi Boosting- +5 psi- 49 psi fuel +10 psi- 61 psi Got to 11 psi and ecu promptly dropped into safety boost. But at 6 psi I was still getting over 50 psi on the fuel pressure. Basically it appears that under all engine conditions the pump is supplying fuel at 3 bars (43.5 psi) above manifold pressure. In perfect order, in other words. After getting home and removing the FP gauge, I started thinking. I know I am getting fuel. I know I have spark. What if I am getting MORE air than the ecu is expecting, ie the MAF is sending bad intel? I looked up the test procedure for the MAF and if you are not getting an ecu error (I'm not) then apparently you check for voltage between pin A on the MAF plug and ground. With engine off but key in on position it is supposed to be 0.8 V. Mine is 0.44 V. With engine idling, 0.8-1.5 V. Mine is 1.245 V. If out of spec the manual says remove and check the hot wire for breaks or dirt. Removed, inspected (looked good) but got out my MAF cleaner spray and gave it a thorough cleaning. Then let it dry, reinstalled and repeated the test. Same results. Is my MAF sensor bad, and is it under-reporting air mass to the ECU? I am too tired to think, or Google right now, so I am really hoping someone smarter than me knows WTF I am talking about. Thanks, Mark (cross posted to twinturbo.net)

There are 5 connections on the CC, but I am ignoring the fuel tank vent and the air intake hose on the bottom. The other 3 are connected to the intake system- The purge line that goes to the balance tube The vacuum signal line to the LH throttle body (right under the boost hose) The third is the purge line that goes directly to the air intake tube right above the canister (also a vacuum port, even when the car is boosting as it is before the turbo). This is what is leading to my belief is that anyone who can hold pressure in their intake system for more than 2 seconds MUST have these three nipples capped. z32bolt- I have that page open as one of the 25 open tabs in my browser that I am going through trying to find my answer.

OK, let me put it another way, since my question isn't getting answered. A Boost leak pressure test only works if the charcoal canister is removed (or the 3 system lines to it are capped). Because from reading the Japanese to English translation in the service manual, the "Signal Vc" line will not hold pressure. I already determined that the "purge" lines won't hold vacuum, so they officially allow "unmetered air" into the system. So a vacuum leak there. Probably not a lot, but really, who can tell? Someone conform this? If you have the factory charcoal canister still installed, can you really pressurize your intake system for 3 or 4 minutes at 5 psi? Thanks...

I had my intake smoke tested a couple weeks ago, and found that my LH recirc valve was leaking. Also the vacuum hose to it had a leak. But there was a major amount of smoke coming out of the area, and I thought something else was going on. So I started testing my vacuum lines again. I found that the short 6mm hose from the left of the balance tube would not hold vacuum. It connects to a hardline on the engine, right next to the IACV/AAC, which goes to the front of the engine, then another 6mm hose connects to a hardline under the LH throttle hose, then to one of the ports marked "purge" on the carbon canister. A 4 mm hose connected to the port underneath the LH throttle plate is connected to the second hardline under the throttle tube, and goes to the port on the canister marked "Signal Vc". Then there is a 6mm hose from a 2nd port marked "purge" on the canister connected to the intercooler pipe, and one marked "Fuel" that is obviously connected to the vent line from the fuel tank. The 2 purge lines will not hold a vacuum. I thought they should be sealed when the engine is off. The Signal Vc port does. The service manual says the inspection procedure is to blow air into the 2 purge ports, and it should not leak, while the Signal Vc and fuel ports should allow leaks (when blowing). So the fact that my mechanic got smoke to come from this area is technically not a bad thing, right? But how can one pressure test a turbo system if this is going to leak air? How much leaking by the canister is normal? When there is vacuum to the Signal Vc port does that close the purge valves or open them? Open what, they appear to be open already? I guess what I am trying to get at is- how does this canister work, and how do you tell if it is borked? Thanks, Mark

http://www.twinturbo.net/nissan/300zx/forums/main/view/906698/Iridium-Vs-Platinum-Plugs-Answer-from-NGKs-tech-Guy.html

I understand you have a lot more experience with these cars than I, but I have to trust the service manual without compelling evidence otherwise. Per the Service manual- Spark plug (Platinum-tipped type): Non-turbo Turbo Standard type PFR6B-11 PFR5B-11B Hot type PFR5B-11 PFR5B-11B Cold type PFR7B-11 PFR6B-11B The European Manual has a completely different plug for the Turbo (go figure) Spark plug (Platinum-tipped type): Non-turbo Turbo Standard type PFR6B-11 PFR6B-11C Hot type PFR5B-11 PFR5B-11C Cold type PFR7B-11 PFR7B-11C Not that it matters, all the -11C plugs are discontinued. Z1 Motorsports sells the PFR6B-11B and state it is the cold version- http://www.z1motorsports.com/product_info.php?products_id=1621 Most importantly from what I read about the design of the OEM plug (extending the tip 1 cm into the combustion chamber) not being replicated by any other plug, I want to stick with the platinums. Just installed a set, they should be replaced every 60,000 miles and if NGK stops making them will I be hosed? I don't expect that to be an issue, drive it about 3,500 miles a year, am I still going to have it in 17.14 years?. I will be 70 then. But I digress. From my more limited knowledge (but lots of reading trying to chase down detonation issues) the PFR6B-11B is the oem recommended cold plug.

Why??? The 300zx TT uses a specially designed plug, made for Nissan by NGK, and is matched to the engine. NGK is on the record as saying none of the Iridiums match up to the oem plug, and will not recommend any Iridium for liability reasons. So why not stick with what Nissan's engineers decided was best? The Platinum PFR6B-11B is the "cold" plug. Just my opinion, and honestly platinums are cheaper anyway.

I live in Montana. While the car is stored from November to February (I have a Nissan Pathfinder 4x4 with studless snow tires for winter) conditions here can be... extreme. Montana is the only state in the lower 48 that has recordable snow every month of the year. To me it would be in the same category as the airbag, the fire extinguisher zip tied to the passenger seat track or the gun I keep in the glove compartment. All things that I hope I will never need, but nice to have if things go sideways.

Started thinking about traction control units- read some good things about the Racelogic Traction Control unit, but was wondering about other options. I remember reading about a unit a few years ago that patched into your ABS system and made it more of a posi-traction unit- if it detected wheelspin the controller would use the ABS actuator to bring that wheel into line with the others. So the Racelogic does it by cutting power, this other one did it by braking at the wheels. For race applications I guess the Racelogic would be better, but I think for crappy conditions (snow/ice/oil/rain) the other approach would be what I want. Problem is, I can't remember the name of the company that made the controller, and my Google skills appear to be lacking today. Does anyone have a clue as to what I am babbling on about? Might as well start the question too- which would you rather have? My primary interest is not in pushing my Z to the edge, I am not wanting to see how far I can push a 21 year old car that is essentially irreplaceable as I am to keep it on the road and not in a ditch. Thanks, Mark (cross-posted to 300zxclub.com)

Veilside- Courtesy Nissan lets you order it on their website, and then you get a "Sorry mate" email a little later. Same thing with all the others. Iangreenfield- The only one I found on Ebay was actually a wrecker in Surrey of all places. Only thing is the picture is a pretty beat up unit, and the email address for the business is a .ru domain. Not too comfortable with that. Z1 had no used or new (spoke to them on the phone Friday) but I called again for giggles, now they think they have one but won't know for sure till someone goes to the other warehouse and checks on Saturday. So no rush on finding shipping costs, I hope to hear back from Z1 by Monday and am praying it will be good news. Thank you all for your help and ideas! Honestly, I got more input from you guys than on the 300zxclub.com forum- which technically has 101,000 members, but only the same number of "active" users as your forum. Ironically I don't think Nissan even sold 101,000 of these cars in the US. Will be updating as events unfold. Mark

If you can email me and let me know what you would want to get the LH one shipped to me I would really appreciate it. I would take both, but I have a suspicion that shipping won't be cheap. My email is mk869 at yahoo.com Thank you!

Hi all, I am brand new to the forum, I live in Missoula, Montana, which is a long way from you but I am desperately looking for a discontinued part and Nissan USA is completely out. So I thought I would try to see if it was still in stock elsewhere. I am specifically looking for a Left-hand recirc valve for my 1993 300zx TT. Part number 14483-40P05. Mine is leaking to atmosphere. I found it on online-parts.co.uk- for £177.10! I want it, but not at that price (nearly US$300, plus shipping). When they were still available here they were $103. If anyone has the website for any other UK based Nissan parts vendors, I can take it from there. Or if you know where I can find one of these (at a reasonable price), that would be awesome. Thanks, Mark