Fuel Injector Leak.
 

I have a 1993 300ZX 2+2 NA with AT. Purchased 2 years ago with 117K miles.

Last week the MIL came on. Pulled the code, 45 - inj leak. So I stopped driving, ordered parts needed for fuel rail, injector kit x 6 ( o-rings, filters and pintle caps), plenum gasket, and throttle body gaskets. New fuel line and vacuum line. Total time start to finish, approx 9 hrs. Parts were close to $100.

Not knowing quite how to do this change I looked to the net and found great tutorials on plenum removal and injector o-ring replacement. Pulled plenum, throttle bodies, cleaned inside and out. (This is a great time to install new PCV valves, when plenum is off the car!) Removing all carbon build up on throttle bodies, cleaned the IAC Valve. Removed fuel rail, pulled injectors (a bit tricky). Ohm'd them all, readings were between 11.4 and 11.6 (Good). Cleaned injectors, Installed new filter, o-rings, and pintle caps. Lubed up fuel rail with 20w oil along with o-rings. Injectors snapped into rail perfectly. Installed new Viton fuel rail seals and bolted rail down. Now re-installing the plenum was a major pain. Before doing so, I smoked a bowl of good bud, figured out the hose connection sequence so I could get all hoses back on and clamped down. A couple hours later the plenum fell into place! (Bolted down all remaining parts, fuel lines, balance tube etc) Everything torque as stated. Connected battery, started car. MIL lamp is now off!

After driving for a week, MIL lamp back on with same code (45). Did a bit more reading on what else may cause this code as I knew that I did not mess up any of the 0-ring seals. (kind of a perfectionist I guess!) Popped the hood and started checking gas line hoses and clamps, found that the return line (close to fuel filter) clamp was not tightened. Fixed this and checked all other clamps associated with fuel lines, tightening all. Started car, MIL lamp went out! Hot Damn, I am getting to be a great Z mechanic! And with this job I assume I must have saved around $1000 by doing it myself.

Previous to this, right after purchase I installed new timing belt, bearings, water pump etc. This was another major job (too me anyway) and again saved around $1000 by doing it myself. The only time this car has been to the shop was to change out carrier bearing on drive-line and install new flywheel, had to do this right after purchase as it could not be driven on the road over 40 as it started to vibrate. I could not get under car to do this is the only reason I took it in (after buying all parts needed).

I am 59, have owned several Z's, starting with the 240 in 1974. Wish I would not have sold any of them! These last 2 jobs made my back really sore but that comes with age! If I can do this myself just by finding out "How to" on the net, then anyone who is mechanically inclined should also be ale to accomplish these tasks and get the job done right! The way I see it is, IF you own a Z then you need to know how it works and how to fix it! I love this 300, gets about 30mpg on the hiway at 65mph. Someday will swap out engine and go with a TT.