OK, so most of the problems I've had with my '99 I've been able to solve on my own or doing some searching on here. But this one really stumped me.

The car is stock except for an short ram intake. It was in a front end accident so I got a good deal when I bought it, but I had to replace bumper, headlights, grill, fenders, fans, rad, etc.. Well one of the problems was that the relay box in the front was smashed up. Doing a lot of testing and tracing wiring schematics, I managed to get the relay box wired up except for the ABS relays. Everything else works, no CEL or anything. But there's been one problem thats been going on since the first day I got it running.

The car runs great at an idle and it runs great while driving. But when you're first taking off from a stop, if you just tap the gas a few times when you start to let the clutch out, you get a knock. But if I slowly bring the rpm up and let the clutch out, there's nothing. I had a spare motor, so I've tried changing coilpacks, crank and cam sensors. I've also put in a new fuel filter, knock sensor, and plugs.

I'm out of ideas. The last thing I can think of is maybe when it was in the accident, it jumped a tooth on the timing. The timing chain sounds fine, doesnt' sound slack or anything. I haven't actually gotten a timing light to check and see how the timing sits, but that's the next thing on the list.

Anyone have any ideas?

 

what kind of gas are you using?

 

All we can get her is 87, 89, and 91.
I was first filling up using 87, but after I heard the knocking, I tried using 91 and still had it. I even tried 91 with octane booster which should have brought it to 93ish, but still doing it.

 

have you checked your plugs if youre getting knock and all you have is 91 octane try using a range colder spark plug that should help your problems with the knock

 

I should add, now with the nicer weather, I've been driving around with my windows down and I can hear it when I just tap the gas at idle.

I tried the plugs, gapped them closer, even tried colder plugs. Still there.

 

dont know if it really matters but Nissan suggests not using ANY aftermarket fuel additive claiming it could harm fuel injection components...a little wont matter but i wouldnt make it a habit.