On March 26th, I installed my Walbro 255lph fuel pump, then got custom dynoflashed by big Al. After he was done, I had a nice smooth, and strong powerband.....for 1 day. Ever since then, my 20 amp Engine control fuse has been blowing(3 times) on the expressway resulting in the car shutting off while driving. At first, I thought that I got a bad fuel pump, but Martin @ AMS tested it and it ended up working properly. Martin concluded that the fuel pump connector was not making full contact, which in turn popped the fuse. The fuse blew again so I put the stock pump back in and changed the fuse again(All connections were tight). Then, guess what.... IT BLEW AGAIN! The fuse only pops while cruising on the expressway(off boost) for an extended period of time(30 mins.). In the city, I can hit full boost, cruise, and the car works perfectly. But when I cruise on the expressway, it blows. The car is also getting terrible gas mileage. Today, I ran a meter on that fuse, and the most pull I got was 3 amps(with accessories on/off). Does anybody have any suggestions? Your feedback is appreciated.
NOTE: THE PURPOSE OF THIS POST IS TO SEEK ADVICE, NOT TO SINGLE OUT THE WALBRO PUMP OR CUSTOM DYNOFLASH FOR MALFUNCTIONS(ANYTHING IS POSSIBLE).

 

Forgot to mention, Al thinks its a bad fuel pump relay/controller.

 

I used to have an air horn on my Civic and everytime I break and honk, my fuse blew resulting in no horn and no tail lights.
After replacing the fuse 3 or 4 times, I replaced it with a higher amp fuse, for instance if the blown fuse was 20amp, I used a 30amp fuse. After that, never had any problem and the car, which my friend owns now, is still running without any problem.

 

You have to be careful with that. A 30 amp might not hurt anything but that 20amp fuse was designed when to much current was going through it to pop. I you just put a higher amp fuse in it, It will not pop the fuse. It'll melt the wires. FYI

 

If it was a relay it would not blow the fuels the relay would blow it self. Your problem might be at the pump. Ask a local person to switch relays for a day and see if that helps. I have seen walbro pumps do what you are discribing. It's most likly the pump.


Good luck

 

Eric, I understand what you are saying, but it is still blowing with the stock pump reinstalled.

 

I just got off the phone with Al, and he offered to assist me in troubleshooting the problem. He is 100% sure that is not his flash, but offered me a full refund if I felt necessary. He insists that the problem is related to the fuel pump relay shorting out. I really hope that he is right, so I can get my Evo running again. His flash did make my car pull nice and strong(I miss that).

 

Electrical systems are very touchy on any any car,If whomever installed the the pump left the connector half way in it must of damaged some type of fuel controller on the car,might be a relay.. Time to troubleshoot

Im sure its an easy fix and AL will help you hes a good guy...

My walbro pump is working awesome,sorry your having problems but Im 100% positive it has nothing to do with the flash...

My car pulls like a jet after his street tune!!

 

I really hope so. I want to drive my car without worrying that it's going to cut out on me.

 

Any other suggestions?

 

Man, I wrote something up, and the server timed me out !!!

Not that I really know anything about how our fuel system electronics work or anything.

We need someone to post up the fuel system schematic from the factory manual. That would help tons.

The way I see it, it has to be either the fuel controller or the flash.

I highly doubt it's the flash since Al only adjusts the injector duty to manipulate the Air/fuel ratio. But ask him to set up your code sid-by-side with another and compare to see if he erroneously changed the wrong values in the wrong section (don't really know about ecu programming)

I think it's the fuel controller. Our pumps are variable current so something has to be driving the current. Probably resistor based. Maybe when the fuel pump was being installed, there was a short-circuit, blowing one of the resistors?? (sorry, I never really versed myself on electrical physics.)

You say the car is getting poor mileage, indicating that you're using too much fuel. After the pump install, would you say that the Walbro was _noticeably_ louder??

I think it's being driven too hard, like it would be during WOT.

 

if the fuse is down stream of the pump (directly) then the current draw of the pump is to great for the system (bad pump) however if the relay is downstream of the pump then it is possible under steady state conditions for the relay to chatter (cycle on and off fast) even though it should be energized all the time, this also could be caused by the pump as the polarity is being changed by a short.

 

Good Luck

 

check for bad ground or pinched wire in the fuel pump harness that can cause issue if it's grounding

just my 2cents

 

I had a Walboro installed about a month ago and I could barely hear it. Now, I can hear it whining pretty loudly...especially when the car is cold. Sometimes the sound gets quieter sometimes it doesnt. Is this normal?