i installed s4 cams on de-t .
i have jwt s4 program.
timmiing set at 15 degres
car idles between 640-780 rpms
car dies every time i push the clutch in any one else
have this problem?i dont have an o2 sensor in watting
for down pipe to show up.could this be the problem?
before i installed s4 cams i drove the car for 2 weeks with no o2
sensor car never died. any thougts would be helpful thanks:confused:

I drove for 2 months with no 02 and S4 cams....i did recently install a 02 and it dramatically did help with idle vacuum went from 6 pounds to `10 pounds at idle. never has died on me

Just raise your idle to like 850-950.

turbo93,

what downpipe are you waiting on...

also, what O2 sensor did you use sr20loper? you have a BB DET?

and when im idling im between 18-20psi of vacuum!

is that normal?

The more the Vacuum the better you have stock cams in your BB I assume if your using stock cams I know a guy who has S3 cams and turbo and his idle vacuum is at 12 pounds mine is at 10 pounds...mine lopes like a bitch...I use the stock 02 sensor

92 SE-R
T25 and S4 cams...
14.413@97.231 with a majorly slipping clutch granny shifting
at 6 pounds of boost

Anything under 14psi of vacum means that you have a vacum leak. 16ps - 20psi of vacum is ideal.

Andreas I'm talking about with aftermarket cams...the lope would cause the adnormal Vacuum at idle wouldn't it? Your trying to tell me C3 cams have a Vacuum of 16 at idle? ...In domestics Idle drops down when you throw in a big cam sometimes so much you can use the break booster because it will cause the car to die

I have done about 11 turbos cars with S3s and about 8 turbo cars with S4s, the vacum on these car were about 16-17 psi of vacum. I just finished a car that belongs to a guy here on the forum his name on the Forum is Danny99 he has S3s with a T3T04E on his 99 4 door SE. When I finished the car we were at 12psi of vacum. I then looked for the vacum leaks that I knew were there and got the car up to 17psi ay idle and at 17 psi at idle I still have a vacum leak at a selenoid where the niple broke off, I am waiting for the part to come in. I bet once it come in I will see about 18 psi of vacum.

When you do go to bigger cams you will loose some vacum but it will not go as low as you guys are at unless there is a vacum leak. I like how you put the biggest cams, C3 to make a point about vacum loss, you are right that with C3 cams would be about 10-12 psi of vacum but the point is you do not have C3 cams you have S3-S4 cams. I am just telling you what your problem is if you think that your cams are keeping your idlle at 10-12 psi then like I said in the past I am not arguing with anyone about their car, you should know your own car better than someonelse so you are right. You will not get any arguments form me, YOU ARE RIGHT.

Andreas Miko.

I thought Vaccum was measured in inches and not psi? Am I mistaken?

Danny

Andreas where did you find these Vacuum leaks at? Maybe this will help my drastically lopey idle....where are the most common spots for vacuum leaks. My car has the JDM intake manifold so no EGR or anything like that...thanks again

Your are right Turbo Miata vacum is measured in inches. Just was making a quick answer and was not thinking about the minor details.

boostedsleeper

waiting 4weeks for down pipe & frontmount kit
from sr20development .

found problem massive air leak after maf
thanks for the help.still dies often hope
02 sensor helps.

turbo93

how much is the downpipe costing you? and what is the size of it?

Im still waiting for hotshot, supposedly theyre releasing a BB downpipe, supposed to be 3" leading out to 2.5"

im sure i would run alot harder once i get a good dowbpipe, i have the stock dowbpipe piece that looks like its 2" in diameter :P

my BB didnt have the downpipe piece, im using one of my buddies CA18DET motor, fit right on, i think the turbos on both our motors have the same exhaust housing

Loper:

as far as what I asked you earlier about the O2 sensor, from what year car are you using the O2 sensor? 91-94 sentra se-r?
also if you are using one of those, how do you get it to fit on the tubo dump piece? yhe threaded hoel it has fits a skinny O2 sensor... im using an B12 sentras O2 sensor cause it threads on, but I dotn even know if its doing anything. I have the BB DET computer and im wondering if I have to use a certain O2 sensor witht he ECU....


thank in advance to anyone that can help =)

Hey Andreas, I currently have C1 cams with the T25 bluebird setup. I'm getting around 12-13 vacuum at idle. Does this sound about right? Also, it is only building boost till 4 or 5 and holds rock steady. What could cause this. I currently have my timing at 5 degrees and my spark plugs gapped at .033. I will change these tomorrow. I also have a 2" Greddy exhaust. TIA.



Terrin
92 SE-R