well, that is what my car is still doing when i hit the nitrous. My last guess is that i just need some PROM tuning and the stock PROM isnt giving me enough fuel at higher rpm. I just bought the 6AL box that many people thought would fix the problem and im still having problems. Another question i have is, would teh stock PROM be running me lean on nitrous on a 355 with cam and heads. 9.5:1 compression, edelbrock TPI base, SLP runners, ported plenum, SLP 1 and 3/4 inch headers and 3 inch catback?

That is my last guess is that the PROM is holding me back. IM gonna put new plugs in it on saturday and pray for that to help. i have a holley/walbro 255 lph fuel pump, that is brand new. accel 23# injectors. all new ignition components. I cant figure out why the hell this isnt working properly.

SOMEONE HELP!!!!!

 

put an adj. regulator on the car and crank the pressure up real high when you plan on juicin.

 

Are you running a wet nitrous system? If so, what are both jet sizes?

 

...And to add to ******* questions, what is your bottle pressure? If your bottle pressure is way low, you will run rich, and it will fall on it's face.

 

Also, if it is leaning out, richen your fuel jets up to make up for what your engine cant.

if its a wet kit.

Dry... dont know what to tell you. Dont have any experience there.

 

Well with a dry kit.. they kit will have a regulator that will boost the fuel pressure accordingly....

So I guess it needs to be known if "wet" or "dry"?????

Rick

 

Im gettin the same problem once i hit it i feel it for a sec then it just falls on its face. Im pretty sure its the bottle heater so i ordered one(i live in michigan weather isnt to great) Im running a wet plate system on a tbi i think my jets are 43 or 42 and 47 i dunno im just using what nos says.(i suck with #s)

 

My adjustable regulator is set at 50 psi at WOT

Gudio, I have the Jets in that NOS suggests...I had another post about this and people told me that it is actually jetted on the rich side.

Blownbird, Im not 100% sure what my bottle pressure is, but i know it was completely full(bottle was frozen overnight and then filled) and it was a very hot day out when i tried it. i know this isnt the best judge on bottle pressure, but its all i have right now, cuz im broke.

thanks for the help guys....can you keep the suggestions coming? i might try to just open the FPR up alot and see what happens, what is the maz that the injectors can handle?

thanks again

 

my TPI car did the same and then I figured out that I needed to hit it above 3000 rpm and its all ok now

 

I tried that today with no luck also. I also tried running it with the bottle turned off to compare the feeling that i am getting. It feels almost exactly the same, like im not getting any nitrous. I know the line and selenoid arent blocked anywhere because i have checked that. I am now thinking that my TB plate is clogged with some debree. the only thing that contradicts this thought is that there is no black smoke like i am running rich and when i check my plugs they are white.

 

check the plugs & read what the engine is doing. I had a similar problem and my nitro filter was clogged. Also, it could be low bottle psi.

 

double check nitrous pressure, I see this alot with guys trying to hit on a low bottle or with low pressure also. weigh your bottle to see if it is cloer to 25-25.5 lbs (full) than it is closer to the 15 to 17.5 lbs (empty or close enough to empty). with wet shots you can only run about 6 to 7 #'s out of the bottle before it quits hitting well (unless you have a heater)

 

well i figured out what the big problem is on of the tubes in the throttle body plate was clogged up with what appeared to be rubber. which wasnt too suprising because that was why my nitrous selenoid failed as i stated in a previous thread. anyway i cleared all lf the rubber out by drilling out the oppostie of the TB plate and through the tube, then plugged it back up.

I went out and tried another nitrous run, I hit it in second gear at about 2500rpm and it pulled really hard til about 4500 rpm then falls on its face. i didnt hear any detonation so i kept it floored and shifted into 3rd the rpm drops as it should and i feel another jolt from the nitrous until i hit the same wall except this time at about 4200 rpm. does anyone know why this could be, i didnt have any time to check plugs after this run because it was almost midnight and i felt like coming home.

One more question, i cant find my instructions anywhere...I bought my kit used so i really dont trust it too much. on the TB plate the two tubes that spray fuel and nitrous. well one of them sprays straight up and down(the one towards the back of the car) and the other sprays off on an angle in toward the engine(the one towards the front of the car) the guy who i got the kit from had the fuel on the one in the front and the nitrous on the one in the back...that seemed wrong to me so i switched it and tried that. shouldnt it be the nitrous on the front and the fuel on the back?

 

Im not so sure you can trust plug reading right after a no2 run,
Nitrous has a habit of really cleaning the plugs.

 

the Nitrous is supposed to spray "through" the Gas to help it attomise. just look @ the angles of the holes & you will see what I mean.

smells like an abununce of gas or a lack of nitrous. pull the plate off of the car & put the pills in it & see what the spray pattern looks like when you hit it. w/o having done it on a car that works it is sometimes hard to gauge.

For those of you that have not done this experiment this is something to try so that you know what it is supposed to look like, so when it does not work, you have a yard stick.

WAG, low bottle pressure.

BW

 

pills as in jets right?

 

Yup

BW

 

You mentioned stock PROM...do you at least have the speed limiter bypassed? It will tend to fall on it's face when ignition is cut out due to ecm governing. Not trying to be a jerk, just sometimes the obvious gets overlooked, I'm not even sure which engine you're running.