I am having a problem and hope i can get some help. Recently my evo IV started backfiring when it reach 4000 rpm. I taught it was spark plugs, MAF sensor, boost leak etc but none of them seems to be the problem. Then i was told to check the voltage on the fuel pump, the stock one is there still but what i realise is that there is only 9 volts that fuel pump is getting and i was also told that i would need to wire a relay direct to the pump to make sure it gets the full 12 - 15 Volts. I have been searching all over the forum to see if i can get a diagram on how to install it but to no success. If there is anyone out there that experienced this and did the relay installation themself can you assist me in how to go about installing the relay in my evo IV.

Much appreciate it.

Thanks.

 

ok. i have hooked up everything properly and gave the car a test drive as soon as i get to like 4-5000 rpm it starts to backfire again and the rpm drops to 0 and the car cuts off. I also replaced the original pump with a walbro but samething. What i realise also is that i took out the panel filter from the stock air box and while the car is idling i just gently blew some air into the MAF and the car cut off, did it again and it still cut off. I am thinking that i should change the fuel filter to see if that makes a difference. Another question if there is a leak after the MAF sensor will that cause the car to idle so bad? I am running out of ideas here any and all help will be greatly appreciated.

Thanks much.