Pewter KPA

You are probably over running that regulator. Fuel pumps typically operate / flow better when run at a lower base pressure. Typically when pumps start to see too much pressure the flow rate drops dramatically. what brand pump is that you are using? You said it dropped 15 psi once you hit boost (how I read it) what was the actual fuel pressure at idle and then when it hit boost?

Are the pumps running in series or parallel? Is the second pump activating under boost or are both running all the time? if at the same time I would recommend maybe hooking the second up to a hobbs switch at say 8 psi so you are not running so much base fuel pressure. You might also need to increase the size of the fuel return line.

I would deff consider getting an aftermarket regulator on that car to at least dial in your base FP. www.foreinnovations.com makes some awesome regulators.

chawkins2001

75psi to 60psi then pulled out of it. Aem Dual e85 320lph pumps in the stock baskets, stock e55 fuel tank setup.

blackbenzz

That's probably your problem. I'm running a Weldon fpr with a return to the tank. If your fuel pressure is dropping your car should be leaning out. What exactly happened at 4k rpm?

Pewter KPA

ok it sounds like both pumps are running full time then. If that's the case your base FP is probably pretty darn high. The higher the pressure the worse the flow. For instance look at the data plot below. Mind you your pump is not on there but it illustrates a common idea. The Aeromotive from what I have seen is VERY close to that AEM pump you have for reference:



Also have you measured pump voltage as it hits boost? This can be pretty critical too as if he voltage drops flow is also going to take a hit.

As blackbenz stated the AFR should take a bit of a dip there and could be the cause of your misfire (lean misfire)

It certainly cant hurt to put a good FPR on the car and a larger fuel return line.

If you have a log you can post up or PM me that might help zero in on the issue.

blackbenzz

I tested voltage on my CLK55 and it was constant but I'm not sure how it is on the E55 since it is factory supercharged. The whole setup on the CLK is different. External pump etc.

I agree on putting in a good fpr and upgrading fuel lines. Some fpr will actually increase fuel pressure at a 1:1 rate with boost.

I went with dual 044 Bosch pumps. As you can see from the graph posted, it can run higher fuel pressure without as much of a drop off.

BI-Performance

Yeah it leans out .8 as the pressure drops and the skip starts to happen.

Pewter KPA

Agreed Bosch 044's are a solid pump choice as their flow is very consistent which is great for dialing in a car.

what is it actually hitting for AFR at that point?

320 dreamer

craig i have a bosch 044 of you need it but recommend against running dual pumps. run a large single like a weldon 2345 or magna fuel 725. if you run dual and one pump takes a dump you will lean out drastically and kill the motor as you won't know it until its too late

chawkins2001

Update is we tested voltage at the fuel pump and it was 12.7v, at the relay it was 13.5v, so it was down at the pumps.

We then rewired with some fresh wiring, and the voltage was holding. The old wiring like beaten up for whatever reason. We ran the car again and the fuel pressure was dropping 15psi again.

Next, we will be replacing the complete sender unit today which will come with a new regulator and fuel filter. We called aem and they said I have plenty of pump and injector for what I am trying to do.

Last, we are putting in brand new coil packs this am too. Funny thing is I was making way more power when on the 50 shot and had none of these issues. Not sure why a turbo setup making less power and the same boost would surface all these problems.

The waste gates are also internal, so maybe all that air been dumped back into the exhaust is causing a ton of turbulence and back pressure coupled with the stock manifolds.

Trying to get this b###h ready for timmayfest and running out of time!!

Pewter KPA

Thanks for the update, You do have plenty of fuel. I think just removing some of the restrictions in your system is the ticket here. It sounds like you have a good game plan.

I wouldn't put much stock in the external wastegate / back-pressure theory. You would need to shove a grapefruit into your exhaust to create that kind of back pressure to cause that level of a misfire.

Thanks for the update and best of luck!

rockthemullet

I think he was responding to me when I asked if he was on the corn

Interesting note on the voltage at the pumps! I'll have to look into mine. You definitely have enough fuel, my bet is that regulator.

I agree with Pewter, it's not a backpressure issue so I'd look elsewhere.

Since you're on E85, I'd throw more timing at it down low. Spool quicker and see if you're breakup is more rpm or boost related... this should help narrow it down. We've got guys running more than 15psi on stock blowers but when the power comes in is totally different

Hammer Down

Craig I may have missed it but are you using the factory ECU?

E55Greasemonkey

FWIW depending on the year the E55 has either 1 relay powering both pumps constantly or later production cars run only 1 pump constantly and the 2nd pump has another relay activated according to engine load by the ECU. Also make sure the relay contacts are not burnt.

BI-Performance

We have done everything mentioned above, and it did not change one thing, right at 4700rpms it starts skipping and breaking up.

Starting to get very frustrated here due to all the extra money invested with no difference. Last resort is to clamp the map sensor which will be done on Monday. If that does not solve it, well, there is not much else that can be done.

We may try routing the waste gates to the open atmosphere to see if that makes a difference too.

I am not sure if RBJ is having similar issues, but an interesting detail is that the previous customer who ran the kit ran into the same issue, and could not get around it either.

Right at 4600rpms on our Dyno Dyamics we are sitting at 498rwhp/620rwtq at 11.2 lbs. That equates to 572rwhp on a 224 Dynojet, and the power is still going up at 45* before the breakup occurs.

My car is a 06 btw.

Pewter KPA

Is there maybe a log that you can post up showing timing, boost, idc, afr etc vs RPM? what did you end up setting your base FP to?

rockthemullet

Well crap.

This right here tells me it's an ECU issue... two different cars, two different fuel systems/spark plugs/coils/etc and it reacts the same. I'm sure there's an employee in Germany right now that would know exactly how to fix this

E55Greasemonkey

E55s built from June 2005 and newer have the 2nd pump triggered by the ecu. Check your door jamb vin sticker for production date XX/XX. Make sure you are not losing that second pump. Both relays for both pumps are in the rr trunk behind the quarter panel trim. Just tossing ideas out there hard to follow the whole thread from my phone.

BI-Performance

As far as I know, you cannot adjust fuel pressure through the factory unit. It is in the fuel tank part of the sender unit.

E55Greasemonkey

Correct. The regulator is pre-set and built into the drivers side
sender/filter unit.

blackbenzz

Map clamp won't help if it's only happening at 11 psi. You were running more than that before without issue

whipplem104

It has been a long time since I looked at one of these. But there is either a standard pressure regulator in there and or there is a spring loaded check ball that is a pressure relief. Probably the best option is to block of mechanically these so they no longer work an put a external pressure regulator in. You can tap back into the lid for a return. Kleemann use to do this with the supercharger kits. There was a stronger spring or something that you had to install for the higher pressure. I know this is a little different but worth looking into.

Pewter KPA

I thought you said above you did everything listed so far. I assumed that meant you put on an FPR and increased the size of the fuel return line.

msheredy

Stupid question but, sometimes it's the little things that we forget, are you in dyno mode?

undercover90

Great job guys, love to see the numbers soon!

Anyone pro efi a e55 yet?

blackbenzz

That's what I was asking you to do in Texas at TX2K14. Nobody has done it before