I've run across problems on TTs a few times recently that everyone needs to be aware of. These problems apply to NAs also but aren't going to be as evident or dangerous, although they still need to be addressed.
I've worked with several TTZ's in the past few months that are experiencing detonation under moderate boost for somewhat elusive unconventional reasons.First ,I found that the $2 Chinese pulleys on E-bay have the timing mark in the wrong spot resulting in the timing being around 10 degrees advanced when you think you have it properly set to 15 degrees. Just last week I ran across an ASP pulley with the timing mark off around 5 degrees (once again in the dangerous direction) that results in advanced timing. Customers have brought us these cars that no one else could figure out, considering it isn't neccessarily intuitive to check the timing mark, and you have to have some other pulleys around for reference. Watch out for this! I can only imagine how many people are going to try to go the cheap route with the E-bay pulleys and end up with broken ringlands.
Maybe they have fixed it by now? I don't know. I e-mailed the people selling them letting them know what they are going to be liable for if they continue to sell them.
Next problem, TTZs detonating prematurely, check a few things then put them on the dyno and A/F is lean like 14:1. Well we usually go through the usual suspects first. Pressurize the intake system, check for any leaks on the intake side of the turbo that would cause the car to run lean. Check fuel pressure. Change the chip. Make sure the injectors are the right ones. Make sure your blue injectors you think are 555cc don't have dots on them (new Stock injectors). Check codes. We come up with nothing and still running lean. So I say change the air flow meter. Technician says; Why it didn't throw a code? I say change the air flow meter. Problem solved.
This same scenario happened twice this month. Scary if you ask me. These were stock visibly undamaged Z32 Airflow meters on clean low mileage cars. They showed none of the classic symtoms of a bad MAF. They of course didn't throw a code. They simply got out of calibration somehow. Bad news when it happens. Good luck on your average mechanic figuring it out, or even knowing its going on without a wideband 02. Once again an elusive problem that can cause big problems. We have began stocking, selling, and installing a lot of PLX wideband O2 set-ups. Its one of those gauges you actually need like a boost gauge.
Watch out for these killers at large! We don't mind selling all the good used and rebuilt motors we have in stock, but we'd rather you go destroy your existing one for some more creative reasons.
Russell Floyd Z1 Motorsports
www.z1motorsports.com
1990+ Nissan Z specialists Used Parts, New parts, Service/Repair and Performance 1200 Carrollton Hwy
Temple, Ga 30179 770-562-8668
770-562-8664 (fax) .JPG)
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