Need some opinions and help <1990 240SX FB /w KA24E

[phatsentra96]

I'm turning the 240sx i got few weeks back into a drag strip car. Taking alot of work but thought that I had everything fixed and took care of but evidently not.Got a few questions for those experienced that could help me out. Please be gentle, I understand engines and whatnot but I'm not a transmission guy or completely understand every little thing about the car yet, I'm still on a steep learning curve.

1) When you turn the car to ON, not starting it, you can hear something under the hood like a relay or a wire shorting out about 4-5 clicks and it stops. It's not my fuel pump, thats working normal. No fuses are blown or anything traceable. Maybe a short who knows, clock has been acting very funny lately and not sure why if it means anything.

2) Also when you turn the car to on but not starting it my speedometer has gone completely ballistic and pegs out. Sometimes it resets and works, other time it reads whatever it wants. If its only in the speedometer and rest of the car is fine not a problem.

--Followed the procedures in the FSM for the A/T CU and only issue I had was the fact that the OD light was burned out, and I kept getting the battery code since I had just hooked the battery back up to it. Its on jacks atm, trying to figure out why my right rear brake is going blue so its not driveable at the moment.

I went ahead and pulled out my VSS and tested it since it was a simple thing to do. Barely turning the VSS it was reading about .1 volt and turning it very fast by hand it would read around .7 volts. Is it supposed to read .5 volts all the time or is mine bad? Would make sense if it was because at normal driving rpm's the car shifts mostly fine, but at WOT it will not shift at all unless you get out of the throttle completely.

By the way, in stock form, minus have anything interior removed from the driver seats back, should I be spinning the tires in D when I leave off the line? It seems like there spinning almost to the 60ft mark unless I feather the throttle to control it. Reason I'm asking is the fact that a few things was out of place, but I have not seen a almost 200k engine be this peppy and responsive, considering the fact that when the transmission refused to shift on me a couple times, she pegged 7k on the tach a few times and nothing has let go or any engine damage that I could find without taking it all apart. Kinda surprised there wasn't a rev limiter keeping the rpm's down, granted it never stayed at 7k for more than maybe a 1/4 of a second if that.

[liquid_cool]

well bro...the 240 is an amazing platform..it can drift..road..drag..just about any form of racing....but for drag racing..if your serious about it..you should guy her down to bare minimums....weight = power and time in drag racing..if your bracket racing ..this is even more true as it comes down to consistancy in your time...now..lets go to the meat of it....#1. test your battery..make shure its reading above 12V..if its not..replace it..that clicking sound is a relay..on the passenger side of the car..if you dont have enough power..they will just click a couple of times and drive ya crazy...

#2.) the rear rotor being blue.......this is serious!...2 things it could be..wheel bearings!...or brake caliper not installed corectly...id vote for the first one..and if it is the wheel bearing and it got that hot...id junk yard dive for a new spindle man..dont use it if it has been damaged...

#3.) your tire spinning issue......if your spinning tires 60' with a stock set up..the only thing i can think of is your suspention is way to stiff for drag racing..and or your tires are to hard.....there are a few fixes for your issue..A.) drag racing coils in the rear...this lets you get a better and more consistant launch...or some spring combo thats much softer than what your runnin now..B.) nitto nt5's or better tires..sumpin super sticky..since i doubt you have a dana60 rear with mad slicks ...thats the best advice i can give ya...

hope this helps a bit man..maybe another niccohead can add to this.

[phatsentra96]

Thanks bro. Figured it was a relay but a couple of us just could never get it down to where it was coming from, but I do have 12 volts on the battery. Just put a new one in it about 2 weeks ago and its holding good. Think I was just paranoid bout it since in the garage it was loud as crap, but at the track other day I never noticed it. Rotor wise, well, we just did new rotors all way around with new pads, so might need to adjust it. If it was the left rear I'd be worried, as previous owners kept slapping new pads on it and the rotors were literally gone, O'Reilly's laughed at me when I tried to get the fronts turned.

I'm slowly stripping the interior over time, but I'm stuck atm waiting for a buddy to come and vacuum the AC lines out for me so I can get all that crap gone, and going to remove all unneeded vacuum crapola off the engine also if I get time.

Setup wise, I think suspension is stock, not fully sure, but haven't really tested things out much yet. Was more concerned over the auto transmission not shifting at WOT to play much, cept for the 2 passes I said F'it and let it rip. Just wanting to have some fun with the car and get used to it, as hopefully next year it should have a ladder bar setup with a dana rearend in it, and an unknown brand V8 under the hood. Gotta get the money saved up first, though.

Just never have drove a 4 banger that could smoke the tires on the drag strip like that. We bought some cooper street tires that were cheap for time being that are soft and shouldn't spin Tried to find me a cheap set of drag radials at the track since we were down there racing for Mopar weekend but only set someone had was so friggin wide, the two tires side by side were wider than my 240.

[liquid_cool]

lol@cooper tires..thats funny..wider than your 240...so your gona slam a V8 in there hu....well..at our drag strip..they hate us import guys couse we use turbo's and beat the s*** out of those guys here with there v8's and superchargers/blowers..lol..you do know..with the rite builder..you can get that 4 banger up to 700+hp man..with that and a light 2500lbs gutted chasis..your talkin speed!..just sumpin for ya to think on.

[phatsentra96]

thanks guys, any suggestions as to the speedo problem and the reason why transmission shifts decently at normal driving but won't shift at full throttle? Stumped and need to get car out of the garage asap.