I have an 01 car with a 125 dry shot, using the 38 jets on a 5177 kit, up top like in 3rd or 4th gear the car surges on and off and the bottle was never empty when it did it, i then put an inline pump and that seemed to cure the problem, and now it does it every once in a while when i have alot of pressure like around 1175-1200 psi of pressure but when i hit it around 1000 is runs fine, the fuel pump i have i got it used, i dunno if i can be going bad or not, so let me know what you guys think.

 

Sounds like a lean condition.Not totally sure though.
1175-1200 psi is too high to spray on.
Keep it around 900-1000 and you should be fine.

 

You're using the fuel pressure safety switch? Bypass it and see if the surging goes away.

 

Yep..as mentioned above...it sounds like the FPSS is set too high. Common problem with the 5177. Bypass it for a few runs and confirm it goes away. If it does youll need to adjust the FPSS that comes with Nos kit 5177. You could just back it down till the surging stops. Not really the preffered method though. I would find someplace that has shop air and an accurate regulator. Hook up a Multimeter to the switch to read Ohms to see if the switch is made or open. Then hook up regulated air to the inlet and adjust the switch to the desired pressure.....maybe 40 psi or so.

 

i don't have the FPSS on the car, so mabye i am using too much pressure as mentioned above. i don't understand how i can be running it lean on a 125 shot with an inline pump

 

I doubt its too much pressure. I regularly run mine at 1150 psi with no problems. Do you have a fuel pressure gauge? Maybe you can Atap to see if the O2s are going lean coinciding with the surge. Also check and double check all the grounds. Do you have a window switch?


One last thing....what plugs do you have and what are they gapped to?

[ March 10, 2002: Message edited by: 383LQ4SS ]</p>

 

[quote]Originally posted by 383LQ4SS:
<strong>I doubt its too much pressure. I regularly run mine at 1150 psi with no problems

One last thing....what plugs do you have and what are they gapped to?

[ March 10, 2002: Message edited by: 383LQ4SS ]</strong><hr></blockquote>

i also ran my TNT wet kit at that pressure.

and i was thinking the same thing too about the plugs. Is it possible that the gap is too large and is blowing out at the upper rpm range?

Chris

 

I am using NGK TR6s gapped at 35, i am gonna put some 36 jets in it and see what happens.

 

Ok...good! Where and how is your bottle mounted?

 

Aslo...try auto tapping to check the 02s. If you dont have one maybe you can get a fuel pressure gauge hook it up and tape it to the window and monitor fuel pressure to see if its dropping waayy out.

 

Surging is from the mixture running rich.

 

[quote]Originally posted by Pro Stock John:
<strong>Surging is from the mixture running rich.</strong><hr></blockquote>

That's ussualy the case,But i've had surging from too lean on Nitrous too.
Also the noids could be pulsing,N2O filter clogged,Bad ground,Low voltage?