Need Help! Car Sputters when spraying.
Thread Starter
Instructor
Joined: Nov 2008
Posts: 143
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From: Plymouth Indiana
Need Help! Car Sputters when spraying.
I have an '87 L98 w/ Miniram. TPiS cam. 2800 stall. Inline walbro fuel pump. MSD-6AL ignition. NOS05151 wet nitrous kit.
I have read through the forum and havent come across anyone with my same problem. I have the kit set-up to a WOT switch, and when engaging the car sputters and falls on its face. I cannot get any power. Can someone please help!
To let you know some of the things I have done. After installation of the kit, adding an inline fuel pump. I reduced the fuel jet by .020. So I am running a .055 NOS and .040 Jet for 100 shot. (NOS suggests .055/.042 stock). I checked my fuel pressure to be 42psi. I know that the system is working, because I hit WOT with car running, but lines at plate unattached. I got nitrous from blue line, and fuel sprayed out the red. This lets me know that the electrical/relay is fine.
Any help would be great.
I have read through the forum and havent come across anyone with my same problem. I have the kit set-up to a WOT switch, and when engaging the car sputters and falls on its face. I cannot get any power. Can someone please help!
To let you know some of the things I have done. After installation of the kit, adding an inline fuel pump. I reduced the fuel jet by .020. So I am running a .055 NOS and .040 Jet for 100 shot. (NOS suggests .055/.042 stock). I checked my fuel pressure to be 42psi. I know that the system is working, because I hit WOT with car running, but lines at plate unattached. I got nitrous from blue line, and fuel sprayed out the red. This lets me know that the electrical/relay is fine.
Any help would be great.
Thread Starter
Instructor
Joined: Nov 2008
Posts: 143
Likes: 0
From: Plymouth Indiana
I have it set at stock timing (-6 degrees). The only reason I reduced the fuel jet is because NOS (Holley) told me to reduce it when adding an inline fuel pump. I have an obd1, and dont know how to datalog.
Burning Brakes
Joined: May 2010
Posts: 1,167
Likes: 2
From: Pittsburgh Pa
Well, 2 degrees of timing retard per 50 shot is what is standard, so if you have 6 your good. It seems you've checked for system function, so that'd be good. If Holley recommended the jet decrease, then I suppose I'd trust that.
The only issue to me it could possibly be then is either you need to gap down your plugs or you have a weak ignition spark due to degraded wires/bad cap, etc. When you raise cylinder pressure the resistance increases and the spark has a harder time jumping the gap. Gapping down, or increasing ignition output is the solution.
Where did you locate fogger nozzle located in the intake?
All I will tell you, is any hesitation is potentially damaging. I've had a lot of experience with nitrous over the years, and I did melt a piston once. The motor was VERY high compression and only about 4 hesitations occurred before I melted the edge of a piston. Be careful. Keep doing your troubleshooting and you'll be good.
The only issue to me it could possibly be then is either you need to gap down your plugs or you have a weak ignition spark due to degraded wires/bad cap, etc. When you raise cylinder pressure the resistance increases and the spark has a harder time jumping the gap. Gapping down, or increasing ignition output is the solution.
Where did you locate fogger nozzle located in the intake?
All I will tell you, is any hesitation is potentially damaging. I've had a lot of experience with nitrous over the years, and I did melt a piston once. The motor was VERY high compression and only about 4 hesitations occurred before I melted the edge of a piston. Be careful. Keep doing your troubleshooting and you'll be good.
Last edited by Z06X; Jun 11, 2010 at 02:46 PM.
Thread Starter
Instructor
Joined: Nov 2008
Posts: 143
Likes: 0
From: Plymouth Indiana
I'll try gapping the plugs, that does sound probable. I have a plate (wet) kit which mounts between the throttle body and the intake, so not a fogger. Yes, I will definately watch the piston melting. I'll do some more adjusting and reply back. Thanks for the help.
Burning Brakes
Joined: May 2010
Posts: 1,167
Likes: 2
From: Pittsburgh Pa
I had a guy come to my shop. He had an RB25 swapped 240sx. For a YEAR he drove this thing misfiring under load. He went to specialists, mechanic friends...you name it. They had him replacing the MAF, coils, plugs, ecu, injectors and more. He spent over 1000.00 following this supposed expert advise.
A friend referred him to my shop and he took me for a ride. I was like...dude, it's blowin the spark out. It's a real distinct misfire. He gapped the plugs and came to my shop damn near screaming like a school girl.
Forced induction applications are very gap sensitive if it's too large. Could very well be the issue, and it's worth eliminating.
A friend referred him to my shop and he took me for a ride. I was like...dude, it's blowin the spark out. It's a real distinct misfire. He gapped the plugs and came to my shop damn near screaming like a school girl.
Forced induction applications are very gap sensitive if it's too large. Could very well be the issue, and it's worth eliminating.
