Running car with VTC knock

[left shin]

Edit: Just had the car inspected at zFever. Apparently there is no VTC knock. Which is weird because I had the knock, and when I grounded the cables and the knock went away.

NEw Question:

Could an exhaust leak present the same symptoms as a VTC knock, and go away when the VTC is grounded? The only things I did in between now and then were change my exhaust piping and flush the engine ( to kill the tick).

[300ZXttZMAN]

When you say flush the engine to kill the tick do you mean lifter tick??? What did you flush it with? I have heard good results from people using ATF.

[left shin]

Yeah lifter tick... with the xtreme engine flush on the z1 site.

[nissanfreak12]

Drain 1qt of oil, add 1 quart of ATF. Run for 15-20 min, idle and revving mixed. Change oil with your choice of poison. Works like a charm, engine is super smooth and quiet, well some what smooth, dealing with other issues.

[left shin]

Tech said it wasn't lifter tick. It was the injectors o.0

That possible? They're loud as hell.

[nissanfreak12]

Get a second opinion, someone you trust. If its as loud as you "say" they are, more than likely lifters. Injectors can get loud, but not overpowering loud.

[datdude407]

The injectors on our cars are loud. The lifters are also loud as well. If It's the VTC it happens when you rev the engine (majority of the Zs I have been around make the noise when reved) & sounds like a noise different than injectors. I would flush the engine with Z1's product or what was said about the atf fluid. I have seen both work with great results. Good luck

[left shin]

I see. Now the knock that I hear only occurs when I first open the throttle and when I release it. It comes from the cam area on the front of the engine. It only happens when the vtc is connected. Could it be the timing belt tensioner?

So you say the injectors should be loud? I put a stethoscope to them and they all sound the same (almost like slurping). Not really sure what I should be looking for. I'll have to put it up to some other car's injector and compare sounds.

I have the z1 new style injector conversion kit. It deletes the upper cover from the injector as well as a piece of rubber on the top of the injector (leaving the gold top exposed). If the piece of rubber at the top of the injector is for sound deadening purposes it could explain why my injectors seem so loud. What do you guys think?

[datdude407]

It's not the tensioners, typically It's the VTC springs that causes that noise. I have no idea about the new style injectors, being that I have a 90 with Phase 1 injectors.

[left shin]

Okay. Thank you guys for the info.

[left shin]

The noise is in fact coming from the injectors. The VTC does make noise but only when first accelerating and decelerating.

I went to the junkyard and pulled some injector caps/hold downs from other Nissans. I replaced 3 of the z1 caps with ones from the junkyard and the noise of the injectors went down considerably. Unfortunately the 90 fuel rail doesn't accommodate the new style injectors or the new style caps too well (apparently they sit slightly lower than the older style). So, now I'm looking at more ways to keep the new style injectors without having so much noise.