Fuel system issues...

[Webby_roller]

Hey guys, just a couple of quick questions about the fuel system.

1. The pin A7 (fuel pump relay) That runs to one pin of a relay. What does the ground pin of the relay connect to (which pin?) The other half of the relay goes from battery to pump to ground??

2. What would a too low fuel pressure and too high fuel pressure do to the way the car runs under WOT?

3. If the fuel pump doesn't receive adequate power levels, would this make the pump flow less volume and pressure???

I am currently having fuel issues, and after speaking to mechanic that was looking at my car today he believes it could be linked to my fuel pump. Crazy A/F ratios under full throttle. Before vtec it was rich, approx 11.5, then after vtec engagement, leaned off too 14.9ish...

I will have a pic of the A/F from the dyno run on when I get to a scanner...

Engine is D15B Vtec
stock everything
worse then stock Exsuast
P28 running P08 maps

Any ideas would be a great help...

[Webby_roller]

Does anybody know what the fuel pressure is for a D15b? I have tried to research and only end up with other forums talking about fuel problems. I am having trouble finding an exact figure as i believe I may of found my fuel system problem..... I just need the fuel pressure the system needs.

Cheers

[Webby_roller]

Hey guys, Just updating the situation at the moment.... I spoke to the mechanic from 999 automotive today at autosalon, and discussed my situation with him.

His recommendations are to wire to pump up correctly, which will be done tomorrow hopefully, install aftermarket fuel regulator (in the future), and check the fuel line size....

Does anybody have the size of the fuel lines from a EG with the D15B7 motor???
I need to check them to see if the ones on my car are big enough.

I am still in need of the fuel pressure of the motor i need.... He said that at idle it should be approx 35 psi, and Full throttle should be approx 50ish.... he wasn't to sure of this so I still need to see if the pressure needed is larger then the pump can deliver.... so any help would be greatly appreciated...

Cheers

[Webby_roller]

Just adding an update for anybody that is tracking this to see if I blow up my car or not!!! Ran new power lines, connected pin A7 to relay, connected power to relay then to pump. Connected inline fuse and then connected to power...

Having trouble trying to find a suitable grounding point for the pump but it was getting dark so I had to stop working.

Will have a pic of the A/F ratio from the run on tomorrow...

[Webby_roller]

New update.... Pin A7 didnt work!!! don't know why.... So i connected relay to another power from the ignition, seems to do the job... All works fine, I think.... Has a healthy whine from the pump, not like the intermittent whine it used to make...

Took it for a drive and it seems vtec isnt activating. Check for codes and it showed code 22 and code 6. Currently trying to work my way through diagnosing the problem...

So it works and it didnt blow up or catch fire!!! :)

[trism]

:thumbsup:

im keeping an eye on this.make sure you let us know if the fuel lines are too small

[Webby_roller]

Will do..... I have checked them out on the ED and they don't look that small.... I am off to check the size of the lines from a D15b7 sometime this week to compare... and if there is no major difference, the mechanic said that it shouldn't be a problem...

When speaking to the mechanic from 999 he said he has never needed to increase fuel line size in any Honda he has worked with as they are always ample size to cope with most, if not all power levels they try get out of costumers cars...

[Webby_roller]

Fixed code 22, seems the relay I installed to replace the non-existent Vtec oil pressure switch had some of the wires come off when i was digging round the back of the motor...

All runs well... sounds nice and healthy.. and runs alot better then in used to...

Still have code 6, replaced all the wiring, and the ECT sensor.. and still have code 6 show up.... No idea why but I will have another go at it on the weekend...