Running Rich

[Gasman]

Can having to much pressure from the fuel pump actually cause the engine to use more fuel?

[Paulie2256]

Id say yes if injector pulse settings are kept the same as more fuel would get through during the pulse.

But to be honest not 100 percent sure.

[ratter]

yes it will under wot and also on cruise/ idle etc if the ecu can not trim it

[daztbo]

Yeah when my fuel pressure was at 90psi I was using heaps more fuel and you could smell it through the exhaust and and was dripping un burnt fuel out the exhaust as well lol it sucked but I put a fuel pressure gauge in front of the fuel rail and found out the pressure was way to high so I started by changing the fuel pressure reg and no change then decided to take the walbro in tank out and put the stock one back in and bingo all fixed back to around 60 psi on idle

[JVK]

Thanks for the info guys it all helps.

Ratter have you had other walbro pumped vehicles output approx 68psi and if you have were there any issues setting up dekka 60s to suit this psi or does the pressure plain and simply have to come back down to oem specs?

Cheers

[IH8TOADS]

I'm surprised you guys are seeing this much pressure. You normally run 4 bar base at idle and under manifold vacuum at idle it is actually a fair bit lower again. 61 at idle with the vacuum line connected to the reg is waaaay too high!

[Mr_4.0]

I have a walbro and surge tank with 044. Stock reg.

My afr's didn't change when I installed the 044.

[ratter]

What about your stft and ltft

[ratter]

Thanks for the info guys it all helps.

Ratter have you had other walbro pumped vehicles output approx 68psi and if you have were there any issues setting up dekka 60s to suit this psi or does the pressure plain and simply have to come back down to oem specs?

Cheers

We do not do fuel pressure checks on every car, but some of the ones we have, have seen a pressure increase with a walbro fitted, normally the ecu will compensate to a certain point, but there are ways to adjust things so the ecu does not need to compensate out of it ordinary range.

If it was at oem specs, the original tune will be closer for fuel control at lower ranges

Edited 06/03/12 11:24 PM by ratter

[wa g6et]

I have 60lb dekas with stock in-tank pump and had a surge and 044 fitted later, afrs ended up a little fat, my tuner trimmed them up. His words were like, it was rich in the low rpm and cold running areas, not totally sure what it all meant. Much better now, uses less fuel and exhaust tips stay cleaner.