LT-10 Map sensor
 

Hi guys, my brother finished wiring in our lt10 to the s5 motor that we have in our 79 rx7 this weekend. The car started and Idled around 1600 but showed no vacuum. I have ran the vacuum for the map sensor to the Re-amemiya intake pipe pre-throttle body (where it has a nipple already there) and now that I think about it, I'm thinking that is horribly wrong.

Now, I am assuming that it will work much better if I run the map sensor to the intake manifold where it will actually read vacuum at idle?

Last but not least, I have ordered the coolingmist "varicool" progressive water meth system from a forum member and just want to make sure that if I do run the map sensor post throttle body and therefor post meth-spray that the map sensor is not going to be disturbed by the liquid coming past it...


thank you guys
chris

Take manifold vacuum from the nipple on the primary runner that would normally feed the OEM MAP sensor. You won't have an issue with the water injection.

Many of the nipples around the throttle body are atmospheric.

Thank you! That worked well. Now the car is reading between 20 and 21 inHg in vacuum at idle. The issue now is that the idle is holding steady at 2300 rpm. I have played with the idle control screw to no avail and I can't imagine that there is any vacuum leaks with that strong of vacuum pressure. Any advice guys? I appreciate it!

Is the cold start cam holding it open?

Sometimes, after sitting for a long time, the bottom secondary throttle plates kind of start sticking as well.