fuel problem

[NCRmtrsprts510]

as some of you may seen me trailering my dime from the santa clara meet, it was because of this fuel problem that has just developed..

 

here's what i have on the 510.

- 3/8" fuel lines

- Walbro 255lph inline pump

- Russell fuel filter

- Aeromotive Fuel pressure regulator.

 

everything was working just fine until thursday, i have at least half tank of gas.

i would watch the fpr gauge and the needle would be jumping between 28-32 psi at idle. (i have it set to 30psi at idle)

then i would rev the motor the about 3k and the fuel pressure would either raise like it supposed to or drop down to 20psi! and the motor would start cutting out! and i keep the throttle open 1/2, then it the motor would just die down and fuel pressure would go down to 10psi!

if i take vacuum away from the fpr it will raise to about 40 psi then opening throttle will bring it down to 30psi sometimes. so i dont think its the fuel pressure regulator.

the walbro whining as usual, but gets pretty hot when driving on hotter days. when i give it throttle i can hear the pump stop whining and thats when i lose fuel pressure. especially when giving it throttle under load (driving load).

 

so bad fuel pump??

[I'm BLUE]

regulators go bad to ,,, IDK just a thought ;)

 

 

Is it a cheapo FP Regulator ? ( less than $40 )

[NCRmtrsprts510]

nope the regulator is a very good it was about $140. im pretty sure it could be the pump, because whenever the fp goes down, i hear the pump go quiet like its going out..

[Nicholas7620]

Try replacing the pump, make sure your wiring is OK first and not vibrating loose at higher rpms/vibrations. :o

[banzai510(hainz)]

PM "icehouse" on here bet he can figure it out in 2 tries. I bet something is not telling the fuel increase. I think jeff(icehouse) uses a walbro also

[Icehouse]

Damn it Hainz what if I can't figure it out... haha

 

Are you running the stock tank? Did you weld 3/8" fittings into it so you will get enough fuel flow? Shit I just checked out your thread again. Damn you've gotten a lot done since last time I checked it out, nice job! So I noticed in the picture of the fuel cell trunk area setup that you have the filter before the pump. I'm not sure exactly how well those filters flow. I know that all high pressure pumps work much better as pushers than pullers. We all know how expensive a new pump is and we all know how expensive fuel line is. Maybe after you do a voltage test at the pump while it is running you could then do some sort of cheater re-plumbing and do a fuel pump test. I think if the pump is getting good voltage that your filter is acting like a restrictor. Your FPR is a nice one so I wouldn't suspect it. How did you by pass the stock FPR? How long have you been driving it like this before the problem?

 

 

You better get a wideband, that turbo could be dangerous :)

[NCRmtrsprts510]

Damn it Hainz what if I can't figure it out... haha

 

Are you running the stock tank? Did you weld 3/8" fittings into it so you will get enough fuel flow? Shit I just checked out your thread again. Damn you've gotten a lot done since last time I checked it out, nice job! So I noticed in the picture of the fuel cell trunk area setup that you have the filter before the pump. I'm not sure exactly how well those filters flow. I know that all high pressure pumps work much better as pushers than pullers. We all know how expensive a new pump is and we all know how expensive fuel line is. Maybe after you do a voltage test at the pump while it is running you could then do some sort of cheater re-plumbing and do a fuel pump test. I think if the pump is getting good voltage that your filter is acting like a restrictor. Your FPR is a nice one so I wouldn't suspect it. How did you by pass the stock FPR? How long have you been driving it like this before the problem?

 

 

You better get a wideband, that turbo could be dangerous :)

 

do you think the pump is sensitive to warmer days? i let it idle for 30 min and the pump didnt get warm or die down. but i drove it for about 5 min and then the pump got warm, and it does kinda seem hesitant when i first hit the throttle.. do u think i should throw a low pressure pump inline before the highpressure pump?

 

the filter i have before the pump should flow through very easy since it is only a 40 micron filter to catch the bigger things that may get into the cell.. i did a voltage test at the pump while its working, and its getting about 13 volts.. and it drops all 13volts so i think the eletrical is good.. do you know if the walbro is brush driven?

 

to pass the stock fpr, i got the ISIS fuel rail adapter that replaces the stock fpr, to run a aftermarket fpr.

 

was working perfectly fine, took it to an autocross, ran fine there, sat for about 4 days, drove it on a hot day, about 87 outside, then started acting up, but when the fuel pump is cold it runs fine..

 

(I do have a wideband.. and have been slowy tuning the ecu.. its running a little more rich as of now, about 13 AFR) :cool:

[Cuts metal like mad]

Maybe a silly question, but are you running a relay to power the pump?

[NCRmtrsprts510]

Maybe a silly question, but are you running a relay to power the pump?

 

yea of course i am.

 

was driving it earlier today and guess what, happened again, i have video this time though.. ive giving it between 1/4-3/4 throttle.

you can hear the fuel pump whining in the back and you can hear it going quite, its not just a little quiet, its like almost completely off. and im holding the throttle open when the rpms die down. and you can hear all the popping and backfiring too.

 

This first video is of me sitting in my driveway, just revving it, no load.

 

 

 

2nd video is while driving in second gear, same about 1/2 throttle.

 

 

 

I WAS going to start diagnosing but then BOOM, the lower radiator hose pops off the radiator and all my coolant goes everywhere, greaaaaaaaaaaaaat, i seriously dont know why that happened?? i was not overheating at all and my cap would start releasing coolant if more than 13psi built up..

 

[NCRmtrsprts510]

another one of me driving it, giving it about 1/2 throttle steady, all the jumping is being done by the engine....

 

[Icehouse]

It has to be a brushed motor since it's DC current. Dude it seems like it's loosing power to me. The only time walbro's are quite is when they are off :) Maybe you have a ground problem.

 

 

I watched the video's like 5 times each. Could there be some shit in the tank that is blocking off the inlet slightly from time to time. It sound's also like the pump is running out of fuel. Does that fuel cell have that foam shit in it? I can think of a few test but nun that are easy.

[I'm BLUE]

Guess you could Run line to Red 5 gallon gas can ( filled with gas of course ) ,,,, test it ! :lol:

[NCRmtrsprts510]

I know for sure that I don't have a wiring issue. Because here's the thing, it works great when the fuel pump is cool to the touch. But as soon as I start driving it and it gets warmer that's when it starts having it's problems. If it was something clogging it wouldn't the problem always be there, or at least after 30 min of idling? I even stuck my hand down in the tank to check the inlet and there is no foam even near it. I can probably call up summit and tell them that the pump is going bad and they might send me a new one for free and see if that fixes the problem. Since I've only had it for less that 200 miles.

[NCRmtrsprts510]

apparently the filter was totally clogged, getting a new one, i really dont know how that filter got so dirty so fast, i can barely see any light through the filter.. Im gonna go with the earl's performance filter this time 35 micron, and im moving the pump before the filter.

[hang_510]

apparently the filter was totally clogged,

 

im moving the pump before the filter.

id suggest keeping it as a secondary, as it seems to be doing a good job of keeping the crud out of the pump.

 

as well as cleaning the tank.

[NCRmtrsprts510]

yea but i need to find a bigger micron filter for the pump.. cause 40 was too small.. like a 100 micron.