The other night I was out driving my newly turbo'd d16 ek, the car was running very a good 30miles. Out of nowhere while cruising (not even in boost) the car out bogs out and dies on me. The car would crank but would not start. I decided to pull the map sensor for the hell of it and the car starts and idles good (drives like crap as you'd assume).

So my issue is, the car starts with the map unplugged but very quickly dies when you plug the harness into the map sensor, any ideas/suggestions?

​​​​​​No leaks detected, tps and map are plugged in correctly. Map sensor is brand new, also used multi meter to check the voltage on all 3 wires. Solid 5v power, good ground and signal wire drops volts as it should when a suction is put upon the map sensor.

Car starts right up without map plugged in.

 

What brand of MAP sensor did you purchase and install ?

 

It is a OEM replacement off of Amazon, but also used a OEM one off my other ek that runs just fine and didn't work either unfortunately.

 

Since you’ve gone turbo, did you use tuning software to adjust/tune your car? Hopefully you’ve installed Hondata or similar components and tuned it. If you only installed the turbo, and expect it to drive the same, then did your untuned engine see even 1psi of boost? If so, then the computer will not know what to do, and your car won’t run right. Then unplugging the MAP sensor might have just let the car start.

If you’re using a Vortec FMU for fuel then you need something to trick the map sensor such as a “missing link” or one way check valves.

Make sure you aren’t boosting even 1psi without something to add fuel. You wouldn’t want to run lean and destroy your engine.

 

I would wonder if your getting a bad vacuum leak.. I think your ecu will let the engine run/idle on a prefixed fuel map or based on TPS position to create a fuel mixture in open loop with the MAP sensor unplugged but as you said after plugging it in tells the ecu it's there then tries to run with a vacuum signal and dies. I would poke around looking for a line disconnected. Also check the ECT and AIT sensors since they link into running with the MAP to control your ecu fueling maps. Doubt the MAP sensor itself is bad since there was no change from using a good known working one. Your not getting any cel light at all are you?
Is your sensor mounted on the throttle body or plenum or does it have a separate vacuum line running to it?
Maybe play around and get some ideas.. If it has its own separate vacuum line, maybe try unplugging the vacuum line to the sensor but leave the electrical connector plugged in and check the vacuum coming from the line with your finger as it idles, See if there's any changes in idle if you cover the vacuum line partially or pinching it closed maybe even leaving it open to the atmosphere. I probably don't make much sense since just thinking random things but maybe could be helpful in some way.

 

Sorry for the late response sir, I am not getting any CEL's.The map sensor is mounted on the throttle body (Running skunk2 tb and im). no vacuum line to the sensor.

I will also note that i am using a chipped p06 ecu, my stock ecu would start the car with the map sensor plugged in but new ecu would not. Went ahead and sent the ecu back to Hamotorsports.com where i purchased it from and they did a full test on the ecu and it came back fine.

 

Wait, wait, wait... so you CAN start the car and it runs fine with the MAP sensor plugged in (both the new replacement one and the properly working one from your other car) while using the stock ECU ??? If so, your issue is the NEW chipped ECU. This could be the programming on the chip or the ECU itself... or maybe even the jumper harness that you are using. But if it works with the stock ECU, the MAP sensor is NOT your problem... nor the wiring going to it.

What size fuel injectors are you using and how much boost are you running ?

 

You prolly have a aftermarket 3 bar map sensor that went bad. They can look exactly like a stock map sensor. You need to check the parameters in the ECU/base map and see what size map sensor is selected, Stock, 3 bar or 4 bar.