Cyl 4 running lean?
05-23-2010, 12:34 PM
#1
Thread Starter
Cyl 4 running lean?
If you read my build in the NA forum, you'll know that I recently bolted up my jenvey itb kit on my s2000. Everything started up fine, but I ran into a couple of problems.
Second problem, my cylinder #4 seems to be running super lean. When I started the car up with the FPR freshly installed and it was set at 20psi, it was clearly detonating, I could see it through my itb air horn. I then quickly adjusted it to around 47 psi. Now it isn't detonating anymore, but the header is glowing red only from the #4 pipe.
I hope my problem isn't my valves or worst. I'll probably check my valve clearances tomorrow.
Second problem, my cylinder #4 seems to be running super lean. When I started the car up with the FPR freshly installed and it was set at 20psi, it was clearly detonating, I could see it through my itb air horn. I then quickly adjusted it to around 47 psi. Now it isn't detonating anymore, but the header is glowing red only from the #4 pipe.
I hope my problem isn't my valves or worst. I'll probably check my valve clearances tomorrow.
05-23-2010, 04:49 PM
#2
Registered User
Originally Posted by freezingcoffee,May 23 2010, 12:34 PM
I hope my problem isn't my valves or worst. I'll probably check my valve clearances tomorrow.
05-23-2010, 05:47 PM
#3
Thread Starter
I'm hoping that detonation didn't do anything to the motor. I didn't move the car anywhere, it just happen during idle, and I didn't leave it on for long periods of time. spark plug seems alright, just a bit white but nothing too crazy.
Tomorrow I'll try swapping plugs and injectors. My injectors are brand new.
Tomorrow I'll try swapping plugs and injectors. My injectors are brand new.
05-23-2010, 09:37 PM
#4
Thread Starter
Problem one is solved, my fuel pressure does stay constant when on.
Problem 2 still persists. I changed the spark plug and fuel injectors around. It is the same, my #4 exhaust manifold is still glowing. I noticed that the #4 airhorn only has one screw holding it on. I wonder if this is causing it to be lean, since the airhorn is not sitting flush with the throttle body. My job tomorrow morning is to check the valve clearance and add another screw to the airhorn to make it sit flush with the throttle body.
I really really really hope it isn't my valves.....
Problem 2 still persists. I changed the spark plug and fuel injectors around. It is the same, my #4 exhaust manifold is still glowing. I noticed that the #4 airhorn only has one screw holding it on. I wonder if this is causing it to be lean, since the airhorn is not sitting flush with the throttle body. My job tomorrow morning is to check the valve clearance and add another screw to the airhorn to make it sit flush with the throttle body.
I really really really hope it isn't my valves.....
05-24-2010, 08:17 AM
#6
Registered User
From what I remember you have to tune the ITBS for each cylinder to make sure the airflow is about the same.
Could it be that 4 is partially open or more open that the other cylinders?
Could it be that 4 is partially open or more open that the other cylinders?
05-24-2010, 09:07 AM
#7
Banned
there is pretty much no way you are seeing detonation at idle, not really possible.
You need to get the car to a tuner and get it on the dyno.
If the header is glowing at idle thats an indication of too much fuel and/or not enough timing.
Do you have a wideband on the car?
You need to get the car to a tuner and get it on the dyno.
If the header is glowing at idle thats an indication of too much fuel and/or not enough timing.
Do you have a wideband on the car?