Your right. Im just afraid im or already did serious damage my motor. I just found out that fuel pump im using is 5 years old and was used by 3 different people lol. So I am ordering a new one. Does anyone know which model walbro 255lph fuel pump I should get? The only made for the evo or universal? The best deals ive found were on ebay for 99bucks w/free shipping. Please let me know.
-Tyler

 

Do you guys think internal damage has already been done?

 

I wouldn't think that you have done any internal damage, my advice to you would be either to check the fuel pump or change your injectors. Here is what happened to me first walbro fuel pump I had took a sh**, car would still run but once boost hit fuel cut drastically. After changing the fuel pump and running the car again the same problem was still happening. We checked over everything and determined that the fuel injectors were running over 100% duty cycle and they just couldn't handle the application. I replaced them with some 450cc injectors. Tuned the car with an apexi safc2 and have not had problems since. I am currently awaiting my rpw stage 1 head gasket and arp head studs.

 

If the car is running well it's probably okay... you can do a compression check to be sure.

As for the fuel pump... change it and re-dyno to see your afr's. You crappy numbers are due to being so lean.

If you still have isssues and want to tune around things then go for the 440's and emanage. You'll still want to use the FMU though. You may just drop it down to a 6:1 ratio though.

 

Thanks guys, I really appreciate you're help on this. The new fuel pump is on its way. I'll install that and dyno it again. If I get the same ****ty numbers in hp and A/F then I gotta tune with the emanage and larger injectors. Ill let you guys know how i make out.

 

also consider the fmu replacement after that. If your fuel pump was thru a few owners maybe the fmu was as well. Fuel components don't like getting dried out multiple times. I'd bet it's the fuel pump though.

After all you'll still want that fmu for tuning later. Piggybacks can only do so much. to big on the injector hurts driveability and gas mileage, while giving good boost power. To small gives good driveability and gas mileage but may hurt boost perfomance. This is where an FMU comes in handy as it can raise the pressure more to increase effective injector size.

You can always change the discs inside to a 2:1 or 3:1 or 4:1, etc... whatever to best suite your application on the best injector possible. I'd say don't go past 440's with a piggy back tuning method.

 

Hey sweet bucket thanks for all your advice. the fmu probably is through 3other people as well. I was looking at new ones and found some going for 100bucks so i may want to replace that as well. I hear vortech really doesnt have a great rep. so i was wondering what you thought about the aeromotive fpr?

 

ive had the same problems....calm down. just get a new fuel pump and take apart the FMU to see if its broken....ther are TQ insturctions online so u can put together FMU correctly. if u look at some of my old posts u will find the answers to all ur questions. YOU DONT WANT TO FIX A PROBLEM BY COVERING UP ANOTHER ONE! GET THIS WORKED OUT 1st THEN GO BIGGER INJECTORS AND EMS.