hello. my fd is not doing so well. we bought it not running and have done a lot of work. something is keeping it from running though. i can crank it, and it will start but then instantly dies. the power fc commander shows the injector duty cycle go to 0 as soon as it starts. any ideas why its doing this? let me know if you need more information but i am stumped.

 

Do you have fuel pressure? Is the fuel pump actually running?

 

yes it has fuel pressure and the pump is running. i can physically see the numbers on the commander show ~10% inj duty cycle. and as soon as it starts, that number goes to 0 and it dies. rpm is still around 800 on the commander.

 

Post up pics of the commander's Sensor and Switch screen, also post up a picture of the monitor screen set on 8, not running with the key on


What was the solution to the commander not reading RPM from this thread? https://www.rx7club.com/power-fc-for...g-rpm-1081916/

 

Just a hunch

But I'm betting if you run a fuel pump wire directly to the battery it will run

 

That is an easy test, jumper the pump at the diagnostic box.

 

i actually did jump the pump to a battery charger with no change in behavior.
ill come back with pictures of the commander in a second

that cas thread is mine. solved that issue by replacing my plugs and wire with those from a spare harness. it now has rpm signal like it should

 

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I know it is your thread, that is why I asked, since you are starting multiple threads in different locations.

Your MAP sensor is not plugged in or it is bad or the chassis harness is damaged. The ECU is seeing MAX boost, it will not run in this condition.

Your intake air temp sensor is not plugged in either. Your OMP is missing or not plugged in.

Press the down arrow to have real time reading instead of peak.

 

thanks for the response!

the other thread was because i thought it was the power fc. i fixed that part of the wiring just with trial and error.

this i thought it was more along the lines of the car itself and not the power fc so thats why i started this thread here.

the previous owner did have some aftermarket map sensor in this car so we put a stock one back in. i didnt check the wires at the ecu so that will be my next step. the omp is bypassed and the air sensor is basically the same deal as the map so i will have to look at that too. the wiring on this car is pretty haggard and im doing my best to fix it and your help has been invaluable so far!

 

IF you swapped the Map sensor back to OEM , You need to go to the PIM VOLT , and put it in NORMAL so that it reads the correct voltages ,

Then take a look at the boost sensor , it should be near 0 it is never perfect stock.

Did you re initialize the power FC before you started playing around with it .

and the fact that the previous owner had a none stock map sensor usually means that they were running the car over 14 PSI , which generally means that they had upgraded injectors .

and the map may be set up for said upgraded injectors

Common issue when running a car lower then stock / bigger wheels is the tires eating through the driver side harness if this has happened to your car it may be shorting out the signal for the map sensor . and causing it to read in boost ( learned this at deals gap )

if possible give a list of mods the car has , or that atleast you know it has . and what you have replaced .

 

we initialized the pfc, would i still have to change the map settings?

the previous setup was big injectors, big turbo, and poorly done. we replaced everything with stock parts and im basically just trying to get the car back to stock form so its actually usable.

 

Not if you are using the stock map sensor. Did you happen to change your engine harness? It looks like you forgot a plug under the dash.

 

press up on the power FC , so that it does not read MAX , isntead it reads live . and take another picture .

Like stated above make sure all the plugs ae connected , But the most important one , the map sensor seems to be disconnected

 

this car is a mess in the sense of wiring. the engine harness is for a manual transmission and the body harness is for an auto trans. there is a black plug with probably 8-10 wires that is not plugged in. the body harness has a similar plug but they are both male connectors. im not sure how to solve this problem yet beyond replacing the entire body harness.

 

Here is a live pic

Something strange too.. when I pos the gas pedal to wot, the voltage goes up to 4.98. Not a big difference but I'd think it wouldn't change at all. Going to swap out the sensor and check wiring in a few hours and report back.

 

With the car on or off? With the car off the pim shouldn't change when you floor it. How far are you from Metuchen? If you can bring the car by I'll take a look.