Lean spike on spray
#1
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Lean spike on spray
Took a video, car almost completely dies on the initial hit.
http://www.youtube.com/watch?v=VvruvQPCsm8
http://www.youtube.com/watch?v=VvruvQPCsm8
#5
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Lines from the noids to the plate is about 24 inches on each. It will be a couple days before I can get an exact measurement, but it's whatever lines come with a new NOS plate. Pressure was right at 1000. Jetting was NOS listed jetting for a 100 hit, so .051 NOS, and I can't recall fuel at the moment. Activated by a push button, timing at 27, narrowbands showed lean, didn't have the wideband with me.
#6
What is base timing? Can you throw a shorter nitrous line and a purge solenoid on it? DEFINATELY don't trust the narrow bands and be weary of the wb. They read O2, not fuel. If the car is pig rich it can read lean.
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#10
What do mean by good? I don't want to sound like an ***, but even though I've seen you on here a bunch I don't want to assume. How thick was the fuel ring and what did the timing mark look like. Chances are that wont tell you anything anyway since you kept in it for the rest of the pass.
#12
Lines from the noids to the plate is about 24 inches on each. It will be a couple days before I can get an exact measurement, but it's whatever lines come with a new NOS plate. Pressure was right at 1000. Jetting was NOS listed jetting for a 100 hit, so .051 NOS, and I can't recall fuel at the moment. Activated by a push button, timing at 27, narrowbands showed lean, didn't have the wideband with me.
27deg is to much timing for a 100 shot
narrowbands CAN NOT be used to tell you anything at WOT
#13
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What do mean by good? I don't want to sound like an ***, but even though I've seen you on here a bunch I don't want to assume. How thick was the fuel ring and what did the timing mark look like. Chances are that wont tell you anything anyway since you kept in it for the rest of the pass.
Dave, it's a bolt on car. Lid/headers/ls6 intake, ls6 valve springs, stock heads, stock cam, stock bottom end. Fuel filter has less than 50 miles on it, and I'm running a Walbro GSS341 in tank. Fuel pressure is usually good, and I didn't see the gauge when this happened. It was good the rest of the way down the track.
#14
What spark plugs are you running? What is the gap?
You need to watch the fuel pressure gauge to eliminate that possibility. With what you have and a 100 shot you should be fine but the pump could be weak etc.
If the fuel pressure is not droping then we can talk about shortning the hose from the fuel solenoid to the plate.
Like suggested above you need to be removing about 4 degrees of timing.
Put a wideband in the car the narrow band readings will not help you.
You need to watch the fuel pressure gauge to eliminate that possibility. With what you have and a 100 shot you should be fine but the pump could be weak etc.
If the fuel pressure is not droping then we can talk about shortning the hose from the fuel solenoid to the plate.
Like suggested above you need to be removing about 4 degrees of timing.
Put a wideband in the car the narrow band readings will not help you.
#15
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Plugs say timing isn't bad. Looked like it could actually take an extra degree. I'll get pics of them next time I'm at the track.
I agree with the narrowband statement. I'm not trying to use them for tuning. I have a wideband for that purpose. I'm just saying the HPT log shows them going from .910mv to .038mv in 2 frames. It's still useful data.
#16
By good, I mean they looked just like they were installed. No visible detonation, speckling, discoloration of any sort. Porcelain was clean, timing mark was right, could actually use a degree or two, fuel ring was right. So I guess that means I'm in the clear the rest of the way down the track.
#17
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What spark plugs are you running? What is the gap?
You need to watch the fuel pressure gauge to eliminate that possibility. With what you have and a 100 shot you should be fine but the pump could be weak etc.
If the fuel pressure is not droping then we can talk about shortning the hose from the fuel solenoid to the plate.
Like suggested above you need to be removing about 4 degrees of timing.
Put a wideband in the car the narrow band readings will not help you.
You need to watch the fuel pressure gauge to eliminate that possibility. With what you have and a 100 shot you should be fine but the pump could be weak etc.
If the fuel pressure is not droping then we can talk about shortning the hose from the fuel solenoid to the plate.
Like suggested above you need to be removing about 4 degrees of timing.
Put a wideband in the car the narrow band readings will not help you.
Wish I could log fuel pressure through HPT...
I'll try less timing and report. I have a wideband, just need to remember to bring it with next trip.
I'll give you guys a call tomorrow to get this sorted out. I'm tired of this working like crap. I really want to go back to a dry kit at this point.
#19
Open up the gap on those plugs to about 34. That gap is to tight for your combo. (Could or could not be an issue)
We need to varify fuel pressure. Even it its a temporary test gauge. We need to find the issue and fix it before you hurt something.
First we need to determain is it a lean issue or a lean spike. While we are problem solving go ahead and put another two pill sizes bigger on the fuel side.
Go out somewhere you can just briefly hit the car and watch a gauge.
If the gauge stays solid and the wideband log shows a lean spike that then richens up you need to shorten the hose from the fuel solenoid to the plate.
Fix the plugs gap before doing anything.
Dave
We need to varify fuel pressure. Even it its a temporary test gauge. We need to find the issue and fix it before you hurt something.
First we need to determain is it a lean issue or a lean spike. While we are problem solving go ahead and put another two pill sizes bigger on the fuel side.
Go out somewhere you can just briefly hit the car and watch a gauge.
If the gauge stays solid and the wideband log shows a lean spike that then richens up you need to shorten the hose from the fuel solenoid to the plate.
Fix the plugs gap before doing anything.
Dave
#20
Middle of the bend is ok, but leaning towards aggressive for a stockish setup... you aren't going to lose enough power to make a difference by taking a degree or two out.... I still don't think that's the problem though...