Nissan Frontier Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
235 Posts
Discussion Starter · #1 ·
So I finally got around to putting my intake manifold spacer, and new plugs in. Everything went according to plan until I started the truck and went to go for a test drive. I got an almost instant P0300 Random Misfire code, along with super rough idle. But more concerning to me was the lack of brakes. They still work, but there is absolutely no hydraulic assist, its just sheer willpower and leg strength to get it to stop.

My assumptions are:

Misfire/rough idle is plugs not being gapped from the factory, which they were supposed to be. So my fault for not checking them. Less likely, but still possible I guess is the ECU needing to get used to the new airflow from the spacer, but I feel like plugs is the winner.

Brakes are probably a missed vacuum line somewhere, but I can't pull it all apart again until tomorrow since it decided to rain on me again. I can't think of anything else unless I just need to go out and work the brakes a bit to push any air pockets through.

Since I'm stuck inside for the evening I figured I'd throw this one out to all you wonderful people to see if I'm on the right track or if there's something else I'm missing.
 

·
Registered
Joined
·
808 Posts
There is probably either an EVAP line that you forgot to hook up, or something is pinched. Did you hook the mass air flow sensor back up?
Again, the plugs may be part of the issue. I never trust the factory , even iridium plugs, always check them.
I would run over the whole engine again, see if there are any lines unhooked etc. Feel around the back if the intake plenum and make sure there are none back there that became loose. Also, try disconnected the negative terminal on the battery and reset the computer. It may help some, and I had to do that when I did mine because the computer doesn't like it when you unplug things when both terminals are still connected.
Good luck to you on that.

As for the brakes, did you accidently pull a sensor plug or anything? It could also be another vacuum line like you said

Sent from my XT1585 using Tapatalk
 

·
Registered
Joined
·
235 Posts
Discussion Starter · #3 ·
Crisis averted! I went back out and took a look and found a vacuum line from the brake booster wasn't quite snug on the nipple. I snugged it up, and Bob's your uncle. Killed the code, rough idle, and brake failure. Little bit brake mush in the pedal cuz I introduced air into the system, but it stops when I tell it to and in unrelated news: damn that IMS adds a buuunch of power. It really wakes it up between 2500-4000rpm.
 
1 - 3 of 3 Posts
Top