Nitrous problems....

boostwhat

Registered User
I have an 89 sc with a "custom" single fogger nozzle system. I have it plumbed directly into the piece that goes above the intake. The jets are 55n 34f (125hp). I am pulling fuel directly from the fuel rail at stock fuel pressure. The system seems likes to pop/crack up and fall on its face. Is this a rich/lean issue. The plugs are not telling me much, seem to be ok. The system is all new. And the wiring is all correct pulling power direct from the battery. Any suggestions? Jetting wrong?
 
Tell me more about your system.

What brand fogger nozzel ? What are you using to trigger the system ? Do you have a fuel pressure switch or window switch ? What size fuel pump do you have ? What pressure is the bottle ? Did you retard the timing any ?

Why are you starting with such a big shot ? 125 is pushing your luck on a built motor. If yours is stock keep the number for a tow truck handy.

David
 
The nozzle is a NOS soft plume. Triggered by a WOT switch. 255 BBK pump. 800-900 on the bottle. No timing retard. How does that sound? How do yo retard the timing? I am going to get a dis-4 box tomorrow. The engine has arp head studs and mls gaskets. Thanks Derek
 
First of all you need to gap your plugs at .035. If you're still running the stock ford double platinum plugs, you've probably blown the platinum discs off the electrodes already. Run a regular plug, or a coated plug, but nothing with a platinum disc or small electrode like a splitfire.

I would jet the kit down to 60hp to start and see how it runs. If all goes well, step it up to 80, then 100. I would not exceed 100 until you become more familiar with the nitrous setup on your car.




boostwhat said:
I have an 89 sc with a "custom" single fogger nozzle system. I have it plumbed directly into the piece that goes above the intake. The jets are 55n 34f (125hp). I am pulling fuel directly from the fuel rail at stock fuel pressure. The system seems likes to pop/crack up and fall on its face. Is this a rich/lean issue. The plugs are not telling me much, seem to be ok. The system is all new. And the wiring is all correct pulling power direct from the battery. Any suggestions? Jetting wrong?
 
I agree with everything Wayne said and will just add a couple more comments.

You don't need any ignition system upgrades like the MSD box your looking at. The easiest way to pull timing is to remove the octane plug, it's located by the EEC test port (pulls 4 degrees I think). I'm using the NGK iriduims because they don't have the platnium disc that Wayne mentioned and seem to be holding up pretty good on and off the bottle.

Spend a few more dollars and install a Hobbs adjustable fuel pressure safety switch. It keeps the system from operating unless the pressure you dial in is maintained (I've got mine set at 55 psi) and will also act as a backup to shut your nitrous system off if the throttle switch sticks. Using the fuel pressure switch will also save you from going lean if your fuel pressure starts dropping for any reason, and will also give your engine a chance to get some air flowing thru the intake manifold before you trigger the system.

David
 
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the system will pop and hesitate if the nitrous lines are not purged prior to use. Air trapped in the lines will cause a rich lean condition. With any wet kit you should always use a purge kit. I use one on my dry kit, and you can feel the diffference from lack of hesitation, and also my track requires it for all nitrous set-ups. This is mainly because wet kits cause back-fires. Anyways....make sure your lines are free of air.
 
fastsc92 said:
the system will pop and hesitate if the nitrous lines are not purged prior to use. Air trapped in the lines will cause a rich lean condition. With any wet kit you should always use a purge kit. I use one on my dry kit, and you can feel the diffference from lack of hesitation, and also my track requires it for all nitrous set-ups. This is mainly because wet kits cause back-fires. Anyways....make sure your lines are free of air.

I've never heard of air in the nitrous lines causing it to pop or hesitate. When I forget to purge, I can't even tell the difference. It doesn't make sense that it would do anything except go rich until the nitrous reaches the intake manifold, which would take less than a 1/10 of a second.

Wet systems do not cause backfires....improper installation and lack of safety devices are what causes backfires.

Damon, spraying before the ACT sensor tricks the computer into thinking it's winter and richens the mixture a little. Here's where I located the nozzel.

nitrous2.jpg


David
 
Get a dedicated pump and solenoid for the fuel side. I have a Focus pump (will support 400 horse no joke) and an external Walbro 255lph for the injectors and a Summit pump and regulator for the juice. Remember a nozzle is designed for 5-9psi and not 55psi. Most small shots do not matter but when you get bigger you get fuel not atomizing and in turn not burning. Which could cause a bog...
 
David,

I knwo but if its to close it will cause teh computer to go haywire...Where yours was located would be just fine
 
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