New fuel pump now misfiring wtf

[NJeuro]

Ok so last week my car died on me and wouldn't start back up check fuel pressure at rail no fuel .. Check power and ground at the pump all ok .. Order and installed bosch 40 pump from 034 Motorsports .. Started it up ran ok took it for a ride started misfiring and sounds like it was backfiring through the intake .. I thought maybe the wot box was messing up sounds like I'm hitting 2 step when I try to accelerate .. So I disconnected the wot box jump the coil wire still misfiring .. Now I checked fuel pressure at the rail seems ok .. I don't know what it could be .. My a/f gauge reads 14.1 and goes up when I give it some gas .. Anyone could help would be appreciated

[milan2k13]

I believe I've read a lot of negative reviews on that pump. What stage are you, that's a high flow pump

[CyberPMG]

I don't have any problems with my Bosch 040 fuel pump. Bought the drop in kit from 034 Motorsport. Do a scan to seee where the misfires are happening. Could be that one of the ignition coils is going bad... or the spark plugs are fouled.

How are the injectors? Looks like you're running way too lean. You shouldn't be that high (or going higher) for your A/F reading. See if you can find someone who can measure the fuel pressure to make sure you're getting enough. The OEM pump (and the Bosch 040) should be delivering 4 bar of fuel pressure.

[NJeuro]

I finally got around to look at the car today traced my steps back to the fuel pump and found the efi hose i use from the fuel pump to the sending unit split open caused not enough fuel pressure causing the misfire .. What type of hose are using from the pump to the sending unit CYBERPMG .. I also notice im running extremely rich 10.0 af at idle and doesn't really change at all while im in boost

[Seerlah]

I'm running regular Autozone fuel hose (I think) in my tank on a B5 A4 with an 044. No issues, despite warnings not to run that hose in the tank. My suggestion is to fit the stock hose if you can.

[NJeuro]

I did the same size hose keeps splitting through , second hose this week
Im thinking that the bend is to much for the hose and causing it to split

[CyberPMG]

I did get the fuel line kit from 034 Motorsport. It's a braided line that goes from the fuel rail back to the pump.

http://www.034motorsport.com/fuel-in...n-p-18675.html

[Wet0willy01]

I finally got around to look at the car today traced my steps back to the fuel pump and found the efi hose i use from the fuel pump to the sending unit split open caused not enough fuel pressure causing the misfire .. What type of hose are using from the pump to the sending unit CYBERPMG .. I also notice im running extremely rich 10.0 af at idle and doesn't really change at all while im in boost

Does it idle at 4 bar?

http://www.audizine.com/forum/showth...ssure-too-high

[Wet0willy01]

Im assuming that you meant the OEM plastic hose from the pump outlet to the tank lid split?

[NJeuro]

Yeah I'm talking about the hose from the pump to the tank lid split. I'm using 5/16 efi hose .. I know it running way to rich if my a/f is 10.0 . I might have to drill the fuel filter return line out has anyone done this before

[jromine]

I did the same size hose keeps splitting through , second hose this week
Im thinking that the bend is to much for the hose and causing it to split

Hey man i know this is an old post but i am having this same issue, did you ever find a solution. Im on my 3rd hose and it just split again.

[NJeuro]

Jromine I finally got some high pressure efi hose that's holding up . I modified the fuel filter and still running crazy rich I can small the fuel not being burned

[TravisSavoie]

You should try the DW300 fuel pump, i just installed mine and i love it!