M50 injector + MarkD chip won't start

[harold30]

Hi r3v,

Today I swapped my stock injectors with M50 green tops (0280150415) from maksinjection.com. Also, installed MarkD chip 91 octane for 17 injectors (new).

After installations, i tried starting the car but i will just crank and crank and it won't start. I recheck everything i did especially the c191 plug. But still no start.
I removed plugs to smell for fuel and it didn't so i concluded that the injectors were not firing. Is there anything I am missing?

My car is 89 325i. Runs great before the swapped. I also searched the forum for the same issue and it seems they solved by replacing with a light green injectors. I'm not getting those before I know what causing my problem.

Any thoughts would be greatly appreciated.

Thanks in advance.

-Harold

[bmwman91]

Did you install the chip backwards? Plugged the fuel rail harness back in? Fuel pump runs?

[harold30]

Did you install the chip backwards? Plugged the fuel rail harness back in? Fuel pump runs?

Chip installed in proper place. harness plugged back in and fuel pump relatively new.

[harold30]

my battery is old and bought a replacement today. it's out of power to due cranking. will attach the new one tomorrow and continue testing. I'm thinking the problem is somewhere in injection system but I'll have dig more on that. I'm also open to any suggestions. keep it coming guys.

[CabbE30]

C191 was my first guess. Did you pull the fuel pump relay to depressurize the system? Did you put it back in? Haha

[CabbE30]

If that isn't it, I know its a small PITA, but try starting the engine w the stock ECU. It should still start even w the M50 injectors.

[E30_fiend]

My guess is the chip is 180° out. Flip it around the other way in the eprom socket and try starting it again.


Taylor

[harold30]

C191 was my first guess. Did you pull the fuel pump relay to depressurize the system? Did you put it back in? Haha

My thought also but i keep on pulling the C191 and put it back still the same. Same thing the fuel pump relay.

If that isn't it, I know its a small PITA, but try starting the engine w the stock ECU. It should still start even w the M50 injectors.

I did that also and still nothing.

[harold30]

My guess is the chip is 180° out. Flip it around the other way in the eprom socket and try starting it again.


Taylor

The chip is in proper place. I know because I put it in that looks like this:



*note: pic is not mine. just showing how i placed the chip

[CabbE30]

Do you have pressure at the rail?

[harold30]

Do you have pressure at the rail?

I'm ordering the tools to check for fuel pressure and noid light. As of now, the least I can do is to test the injector harness and the resistance of injectors with multi meter.

[harold30]

Little update:
1) test the resistance to each injectors and showed 17.+ ohms all.
2) checked the injector for damages found nothing.
3) checked the injector harness and i got 11.7+ volts each.
4) check fuel rail for found plenty (though, i didn't use a gauge 'coz i don't have one, i just removed the fuel hose feeding the rail)
5) removed plug/s and smell for fuel but it didn't. so i conclude no spark done.
6) swapped to stock chip and still the same.

could it be a bad ecu? any thoughts?

[Balleristic31]

Make sure the coolant temp sensor is plugged in all the way.

[harold30]

Make sure the coolant temp sensor is plugged in all the way.

done doing that.

[harold30]

just a thought, what's the difference between m50 green vs light green injectors? could it be that the light green injectors will work fine with m20?