94 Q45 - 34 Knock Sensor & 51 Open Injector Circuit code displayed

[bspake]

I recently purchased an 94 Q45 with 116k, the car's check engine light is on and recently I have been experiencing terribly slow acceleration. The code results are 34 Knock Sensor & 51 Open Injector Circuit code. I spoke to the local Houston Infiniti dealer and he said replace all 8 injectors and both knock sensors. He said the injectors are $250 a piece. Is this accurate information? Obviously the dealership is going to be more expensive, so I'm hoping to find a better deal somewhere in the Houston area. Any input would be greatly appreciated!

[maxnix]

I guess you did not obtain any previous maintenance records?

Have you tried BG44K? Redline SL1?

Read the multiple articles here or at http://www.Q45.org on how to ohm test your injectors and knock sensors and report back in Infiniti Online Mechanic.

Welcome to NICO.

[qship96]

What the dealer didnt tell you is the out the door price will really be around $5,000.00 to complete the job.......aprox $1500 for underplenum kit with all hoses/knock sensors/harness, $2,000 for all 8 injectors,$1500 labor to do job......might as well spend an additional $500 on doing plugs/valvecover gaskets while it is apart.

[bspake]

I have not tried BG44K or Redline SL1 before. I will give this a shot for the time being, thanks.

[maxnix]

And please also perform the tests suggested above and report back.

Iso-Heet (NOT HEET!) might be good also if you have condensation or contaminated gaosline in your tank. Won't hurt to use in combination a couple of times.

For BG44K

http://www.bgfindaship.com

Call first before you go.

[goody90q45]

The code results are 34 Knock Sensor & 51 Open Injector Circuit code. I spoke to the local Houston Infiniti dealer and he said replace all 8 injectors and both knock sensors......

At this point follow Maxnix's advice and ohm your injectors. Don't take it to the stealership to have it done because they're going to tell you to replace all 8 and the cost could very well reach as high as $5000 (qship is right) once they have you in their grasp with the plenum off your engine.

If you don't own a voltmeter go buy one for $10-$20 at Radio Shack, Best Buy, etc. Ohming your injectors is simple. If you have 10 minutes and don't like getting your hands dirty this test is for you.

With the engine and key off, the meter set to ohms resistance, and the positive probe of the meter to the positive post of the battery, measure the resistance at each of the 8 pins on the connector and record the reading. My guess is you have at least 1 or 2 injectors reading above 14.0. The connectors are located on the passenger side end of the plenum and you may as well measure the knock sensors while you're there. Let us know what you find and we can go from there.