i had a b20 vtec installed turbo it will not start.
only electronics i changed was i converted to a gm 3 bar map sensor.
no check engine lights
i turn it over it will sound like it is going to start up and then sputter and die
fuel pressure is fine
help any advice.

 

You can't use a 3 bar map sensor with a stock computer.

 

sorry i forgot to say i have a apex vafc does that help any

 

you can run a 3 bar with a v-afc just make sure you have it adjusted accordingly with what injectors you have. also make sure on the v-afc you have the right in and out settings.

also sounds stupid but check your fireing order.

 

i am running skunk 2 stage 2 cams for NA could that effect anything.
i have not even started the car with them could they cause the car not to start

 

no, that wont affect anything. what size injectors do you have

 

old school h22 i think they are around 310cc

 

stock injectors just a 3 bar map sensor added hmmm. You aren't richening up, if anything you are leaning out from the 3 bar's voltage manipulation. Try adding fuel in increments of 5% below 2000 rpm on the low cam map and see if that starts it. Stop when you get to like 40%.

 

Also have you tried giving it gas when you start it to see if it will at least spin through the rpms a little?

 

thanks you were right the injectors were the problem
i converted back to the honda MAP
looking for some dsm injectors 450cc to convert back to 3 BAR MAP
thanks for the help

 

you can run a 3 bar with stock injectors. the map sensor does nothing but give voltage , as long as you have the ecu calabrated right it will be fine

if you using a afc, the stock setting are 6 in and 6 out. i think with a 3 bar it's like 4 in and 4 out, im not for sure. do a search for afc 3 bar or something

platinum.

 

i will try see what happens

 

Yea you can run stock injectors with the 3 bar you just have to know how the voltage division works. You also need an FMU.

 

i tried it out it was 6 in 4 out with h22 injectors on the vafc
i have a vortech fmu will that work??? why do i need the fmu
if i upgrade to dsm 450 cc injectors do i still need the fmu

 

Inlinepro would say Yes.
I would say get motec