i have a 99 em1 swapped with a b16b it has bolt ons a fuel rail and regulator (can i list brand names or is that a no no?) and an s300...
it ran great for a while but it has been giving me some trouble for almost a year now...
in the beginning the headlights would dim on and off the speedometer would jump a little bit then the speedometer started jumping all around and then just pooped out totally before i had a friend look at it he reloaded it with a stock CTR map and it ran perfect for about a week then it started doing it again...
now the speedometer works half the time i'll be driving and it will do it it makes feel real slow and of course i cant hit vtec
i'll turn it off for a while sometimes and it will go back to normal for either the rest of the night or for about 30 minutes
what would be causing this i figured maybe the sensor was bad but that wouldnt cause the headlights and all the other lights inside to dim would it?

 

Cels?

 

wait huh lol?

 

Check Engine Light

and yes you can list brands.

 

check engine light will come on when the speedometer is dead and just sits at zero without moving at all
sometimes it comes on when its jumping around

 

Pull the CEL codes. Click CEL in my signature.

 

alrite imma try that
now when the check engine light comes on it only comes on when the speedometer is dead but when you turn off the car and turn it right back on it disappears... isnt a check engine light supposed to stay on until the code or codes gets cleared?

 

When the CEL turns on, leave the engine running while you pull the code.

 

i have an s300 so i should see the code on there when it comes up right?

 

Yes.

You say the CEL only comes on when the speedometer is dead? Sounds like a VSS issue. The CEL for a VSS issue will shut off when you turn the vehicle off, but will return once you reach ~5mph.

 

I would replace the VSS without even checking for codes if your speedo just randomly works. Takes like 3 minutes. If money is an issue, you can get lucky and find one at a junkyard or craigslist for like $20. Otherwise they can get pretty pricey from the dealership.

 

Have you tried replacing the alternator or having it bench tested? My car missed and the Speed was jumping up and down. Come to find out it was an alternator.