Does this look like I have a boost leak?
Mar 10, 2007, 09:57 AM
#1
Does this look like I have a boost leak?
Alright guys, I have been suffering from what I thought was just fouled plugs giving me a misfire. I swapped out my BPR7ES yesterday for BR7ES gapped to .26. Last night I did a log and didnt get what usually feels like bad misfires throughout the rpm range. What I am noticing is that my load is kind of all over the place which leads me to believe I am getting a boost leak.
I havent done a boost leak test yet but I just wanted some opinions from you guys before I do one and then take a hard look at the ignition system.
By the way I am only running around 19-20psi peak.
I havent done a boost leak test yet but I just wanted some opinions from you guys before I do one and then take a hard look at the ignition system.
By the way I am only running around 19-20psi peak.
Mar 10, 2007, 01:40 PM
#2
I dont think your load looks abnormal. What were your previous plugs gapped at and what did the plugs you took out look like? My old Dynoflash tune ran pretty rich. It's kind of hard to see the problem without wb readings. I've seen a few tunes knock a little when coming into boost and it's normally not a big problem. You might try pulling a little timing to see if it goes away. Could just be the limits of the fuel / weather / timing.
Since you dont have knock in the higher rpm ranges it is likely to be boost related misfires. You could try closing the gap a little more on your plugs, my car is pretty sensitive to plug gap.
When are you feeling the misfires? Are you actually just feeling the knock that is being logged?
Since you dont have knock in the higher rpm ranges it is likely to be boost related misfires. You could try closing the gap a little more on your plugs, my car is pretty sensitive to plug gap.
When are you feeling the misfires? Are you actually just feeling the knock that is being logged?
Mar 12, 2007, 07:58 AM
#3
I dont think your load looks abnormal. What were your previous plugs gapped at and what did the plugs you took out look like? My old plugsjust looked likenormal fouled plugs when they were done. They were gapped to .25 My old Dynoflash tune ran pretty rich. It's kind of hard to see the problem without wb readings. I've seen a few tunes knock a little when coming into boost and it's normally not a big problem. You might try pulling a little timing to see if it goes away. Could just be the limits of the fuel / weather / timing.
Since you dont have knock in the higher rpm ranges it is likely to be boost related misfires. You could try closing the gap a little more on your plugs, my car is pretty sensitive to plug gap.
When are you feeling the misfires? I usually feel the misfires at the onset of boost, where you see the counts of knock Are you actually just feeling the knock that is being logged?
Since you dont have knock in the higher rpm ranges it is likely to be boost related misfires. You could try closing the gap a little more on your plugs, my car is pretty sensitive to plug gap.
When are you feeling the misfires? I usually feel the misfires at the onset of boost, where you see the counts of knock Are you actually just feeling the knock that is being logged?
Mar 12, 2007, 08:52 AM
#4
well no problem, when I was having spark related misfire.. it was popping when I would go WOT, right at the boost spike. Until I changed plugs I just turned the boost down and it went away. Knock feels a little different, I cant always hear it but I can feel when timing is being pulled.
Mar 12, 2007, 03:59 PM
#5
I am basically having the same misfire problem as you did. What did you end up gapping your plugs to? .22? When I get back from Florida I will have to change the plug gap. I definitely need to get rid of the crappy Magnecores too. I wonder if Autozone replacements would be better.................................
Mar 12, 2007, 07:36 PM
#6
A boost leak would show an unusual increase in airflow hz with respect to IPW or load when compared to when you feel your car wasn't leaking. Airflow #'s look normal to me if your using HKSrs intake.
Hate to say it but the only way to tell is to get your hands dirty and pressurize the system to about 15psi and it should hold
Severe missfire I think gives a code 0300 but a WB can detect slight miss
Hate to say it but the only way to tell is to get your hands dirty and pressurize the system to about 15psi and it should hold
Severe missfire I think gives a code 0300 but a WB can detect slight miss
Mar 14, 2007, 10:24 AM
#13
I would encourage people to do boost leak tests even when you dont think you have a leak, periodically throughout the year. You'll be suprised to find a few every time.
Mar 15, 2007, 05:50 AM
#15
How can you see misfire from a evoscan log?
There are only three ways to spot miss I know:
1) WB sharp lean spikes
2) Sometimes Code 0300 (random misfire)will be right
3) Oscilloscope (dont ask how?)
4) If miss is bad enough the car would pause for brief periods on accel
There are only three ways to spot miss I know:
1) WB sharp lean spikes
2) Sometimes Code 0300 (random misfire)will be right
3) Oscilloscope (dont ask how?)
4) If miss is bad enough the car would pause for brief periods on accel