nitrous surge

[sldhemi]

ok, im all out of ideas... my truck surges really bad when I spray it... A/F is good, stays around 11.7-11.9 with about 800psi of bottle pressure. Im spraying a 100 shot and pulling 4 degrees of timing across the board

anyone have an idea of what might be causing this surge?

[zemog255]

Bad bottle fill maybe? I know when the bottle gets low it does all kinds of weird stuff. Your afr staying so consistent though doesn't really support that idea though.

[sldhemi]

no, i fill my own bottles... its done it with 12lbs of nitrous in a bottle as well as with 5lbs in one

it doesnt feel like a surge from low pressure, it feels like the nitrous is switching on and off. thats how hard it surges... im going to bypass the window switch tonight and see what it does. if it still does it ill just put it on a button, im thinking its something wrong with the nmu or window switch

EDIT: I just talked to my tuner and he told me how to reprogram my NMU that should take care of the problem. Or putting the resistor in the TPS wire should take care of it. I'll try that tonight and see

[jordan21210]

you hittin the track tonight amigo?

[sldhemi]

tracks closed tonight, ill do a couple street runs trying to fix this nitrous crap but thats about it

spent all day yesterday at the track

[jordan21210]

haha nice...i was playing with my truck for most of the day today...think i've finally got a decent tune. just got back to BR and it didnt stall once...though it came close a couple times, lol

[kfed]

Check your solenoid, and all the connections. I had a bad wire and it would arc the odd time and do the same thing

[Gary's Hemi]

You going to 12 Stones friday??

[rumblebee175]

you dont have the bottle laying down do you

[Onebadbee]

You going to 12 Stones friday??

if there are 12 stones in the nitrous line that may be causing the surge did you clean the line

[sldhemi]

Yea I'm sure I'll be at 12 stones gary

rumblebee175 the bottle is mounted with the brackets, so yes it's laying down

kfed that's what I'm kind of thinking it is, I reset the nmu and when I press the pedal with everything off I can hear the solenoid opening. I'm gonna check everything this weekend

[rumblebee175]

well probably not your problem since the bottle is full but when the bottle laying flat down the pick up hose will not work sometimes with the bottle thats less than half full

[sldhemi]

yea i know what your saying, but most of the time i clock the bottle so the pickup is still at the lowest point... but like i said it does it whether i have 12lbs in a bottle or 5lbs

[RandTx]

What size resistor is that? I guess it goes on the line tapping the TB voltage?

[sldhemi]

What size resistor is that? I guess it goes on the line tapping the TB voltage?

correct in goes in the TPS wire... Zex tech line told me to get an 82kohm resistor

[RandTx]

wow 82k ohm, I wouldn't have never guessed nearly that high a value.

[sldhemi]

yea it threw me off a little too, idk we'll see i guess

[kfed]

Im still thinking it has something to do with the solenoid, something could be dirty inside, sticking, something causing resistance in the power line

[sldhemi]

I'll pull the solenoid off this weekend, is there any way to clean it?

[sldhemi]

Well I haven't necessarily fixed the problem but I've isolated it down to something with the window switch. I had it wired where it takes about 5 seconds to bypass it so I figured what the hell. So on just the WOT switch it works flawless.

So I either tapped into the wrong wire on the coil, or there is a wire problem or short in the window switch. The next chance I get I'll go through it all and see.