Hey so you mentioned using a Toyota o-ring in the factory neck of the pump? I really hate the stock design of these pump slip fittings and always use a evo fuel pump grommet to seat into the factory sending unit. I’ve had issues with the o-rings style leaking pressure when the regulator gives pressure feedback it blows the fuel back into the tank through the o-ring on the pump

Also I’m assuming you are running an external relay to the bigger pump and not trying to run a big pump on the factory connector?

Chrysler kid is right. Honestly, I'm shocked you went through all the effort to weld on AN fittings to the top of the hanger and you kept the worst piece of the design: the nozzle assembly under the hanger. There's almost no way that thing is sealing correctly.

Cut that thing off, weld on a barb that you can couple onto with a hose setup, and that will likely solve the issue.

I.....had different issues with a Walbro 450 setup, but again was using a Fuelab Regulator. One of my trials and tribulations led to ditching it for a Radium Pulse Damper and Regulator Combo, and upping to a 525.

chrysler kid said:

Hey so you mentioned using a Toyota o-ring in the factory neck of the pump? I really hate the stock design of these pump slip fittings and always use a evo fuel pump grommet to seat into the factory sending unit. I’ve had issues with the o-rings style leaking pressure when the regulator gives pressure feedback it blows the fuel back into the tank through the o-ring on the pump

Also I’m assuming you are running an external relay to the bigger pump and not trying to run a big pump on the factory connector?

Click to expand...

That's exactly what I used, too. I had the impression it's a Toyota part, it might be from Mitsubishi, I don't remember but I know I've read on this forum that's the best alternative to the original o-ring.

I've tested the pump to about 80psi before installing it and everything was good, no fuel leaks. I do have a re-wired fuel pump kit installed.

Tiki2777 said:

Chrysler kid is right. Honestly, I'm shocked you went through all the effort to weld on AN fittings to the top of the hanger and you kept the worst piece of the design: the nozzle assembly under the hanger. There's almost no way that thing is sealing correctly.

Cut that thing off, weld on a barb that you can couple onto with a hose setup, and that will likely solve the issue.

I had different issues with a Walbro 450 setup, but again was using a Fuelab Regulator. One of my trials and tribulations led to ditching it for a Radium Pulse Damper and Regulator Combo, and upping to a 525.

Click to expand...

I got to say I've spent many days thinking about the way I should mount the fuel pump. I wanted to get rid of that part from the hanger but I didn't had so many alternatives.

I could buy some adapters and use a hose to connect the pump but If i remember correctly the inside diameter of the fitting was smaller then the outlet inside diameter of the pump. I thought it will be restrictive, I know the way it is now can be restrictive too. I can re-do the hanger if I have a better alternative or if that's the problem.

Again, if we taking about where the flow can get restrictive I can say the fuel flex sensor can be restrictive too, or the 10 micron paper filter. I'm thinking also to get a stainless filter if I have to, seems it's much better for high flow.

About the fuel dampers, I took it into consideration too but again, searching the internet I couldn't find any good feedback form people using them. In most of the cases they were says they couldn't see any difference. I don't think the problem i have it's a problem that a fuel damper can solve, I think the problem it's in another place.

CDgr97GSX said:

I got to say I've spent many days thinking about the way I should mount the fuel pump. I wanted to get rid of that part from the hanger but I didn't had so many alternatives.
I could buy some adapters and use a hose to connect the pump but If i remember correctly the inside diameter of the fitting was smaller then the outlet inside diamter of the pump. I thought it will be restrictive, I know the way it is now can be restrictive too. I can re-do the hanger if I have a better alternative or if that's the problem. Again, if we taking about where the flow can get restrictive I can say the fuel flex sensor can be restrictive too, or the 10 micron paper filter. I'm thinking also to get a stainless filter if I have to, seems it's much better for high flow.
About the fuel dampers, I took it into consideration too but again, searching the internet I couldn't find any good feedback form people using them. In most of the cases they were says they couldn't see any difference. I don't think the problem i have it's a problem that a fuel damper can solve, I think the problem it's in another place.

Click to expand...

Steve mentioned this, did you pressurize the manifold (and the FPR) and turn the pump on (like a BLT, but engine is off, fuel pump on)? If you log Fuel Pressure during that test It might at least rule out something.... it should show a nice beautiful curve close to 1:1 rise.

If you look at the first log and masked everything but the MAP sensor and the Fuel Pressure you'll see they don't track very well.
The battery voltage looks pretty solid at 13+ volts.

Right, and if you see the same issues with the engine and injectors out of the equation, it tells you potentially where to look or not look.

steve said:

If you look at the first log and masked everything but the MAP sensor and the Fuel Pressure you'll see they don't track very well.

Click to expand...

CDgr97GSX said:

Base pressure I really don't know why I have it displayed and what's exactly showing.

Click to expand...

Aha - that's what that item BaseFuelPress is. It's calculated from the MAP sensor and the Fuel Pressure sensor.
It is Fuel Pressure minus Manifold Pressure in psi.
It was added as a display item in 2014.
Here is the changelog for it:


Yeah, it's so all over the place you could hardly tell what it's supposed to be just by looking at the logged numbers.

CDgr97GSX said:

Since I had the pump out I've changed the fuel pump filter and after starting the fuel pump from ECMLink without the engine running the fuel pressure was steady at 43 psi but once I started the engine it started to fluctuate again.

Click to expand...

CDgr97GSX said:

I can say the analog gauge mounted on the regulator it's also moving although not so much and hard to see but it's not steady for sure.

Click to expand...

CDgr97GSX said:

I can start and stop the pump, pressure it's still 43 psi and steady at around 43 psi.

Click to expand...

CDgr97GSX said:

I didn't have a problem to set the fuel pressure at 43psi I could even go lower.

Click to expand...

So it sounds like you have a mechanical gauge on the regulator, and you've been setting your base pressure to 43 psi by that gauge.
But in both of the logs posted, when I look at the "key on before cranking" part at the start of the log, the BaseFuelPress is about 33.5 psi in both of them, and it's fairly steady there.
So that is weird.
It looks like even before cranking where we thought it was better, the Fuel Pressure you get from the electronic sensor is wrong - it's off by 10 psi from the mechanical gauge.
Or did you just reset your base pressure to 33.5 psi before doing both of these logs?

CDgr97GSX said:

From what I can tell, looking at the logs, the problem seems to be when car goes in open loop the injectors are shutting off.

Click to expand...

If you are accelerating in open loop, then obviously the injectors shouldn't shut off.
Normally, the only time you see InjOn time go to 0.00 and open loop at the same time, is when you are rolling along down the road and you take your foot off the gas. I do see that in your 2025 log and it looks normal. That's Coasting Fuel Cut.
But it does sound like there is some new problem.

Tiki2777 said:

Steve mentioned this, did you pressurize the manifold (and the FPR) and turn the pump on (like a BLT, but engine is off, fuel pump on)? If you log Fuel Pressure during that test It might at least rule out something.... it should show a nice beautiful curve close to 1:1 rise.

Click to expand...

I did a BLT but I haven't tested the regulator on the same time or after. I didn't think abou it at that time, I thought everything was working as it should. I definitely have to do this test so I'll buy a small air compressor with a pressure regulator valve so I can test it at different pressures.

steve said:

If you look at the first log and masked everything but the MAP sensor and the Fuel Pressure you'll see they don't track very well.
The battery voltage looks pretty solid at 13+ volts.

Click to expand...

I've seen it on log and also on the Innovate gauge while I was driving the car. That's way I want to fix it so I can ask someone to remote tune the car. With that fuel pressure fluctuation it's no point to start working at the map.

We're on Boost said:

Aha - that's what that item BaseFuelPress is. It's calculated from the MAP sensor and the Fuel Pressure sensor.
Yeah, it's so all over the place you could hardly tell what it's supposed to be just by looking at the logged numbers.

Click to expand...

I knew it was a reason I had it on the displayed values. I thought it will show the numbers I should get on different manifold pressure but I seems it doesn't do that.

We're on Boost said:

So it sounds like you have a mechanical gauge on the regulator, and you've been setting your base pressure to 43 psi by that gauge.
But in both of the logs posted, when I look at the "key on before cranking" part at the start of the log, the BaseFuelPress is about 33.5 psi in both of them, and it's fairly steady there.
So that is weird.
It looks like even before cranking where we thought it was better, the Fuel Pressure you get from the electronic sensor is wrong - it's off by 10 psi from the mechanical gauge.
Or did you just reset your base pressure to 33.5 psi before doing both of these logs?

Click to expand...

Yes, there is a mechanical gauge too and the base fuel pressure have been set to 43psi and never changed after.

The fuel pressure from the log is after the engine has been started before. I don't have a log with only the fuel pump on but like I said, if I don't start the car or run the pump for few days then I get 43 or 42.5 psi steady on both gauges on first start of the pump from ECMLink. After starting the engine is all over the place and never get steady again unless I release the pressure from the hoses or I don't start the pump for few days.

We're on Boost said:

If you are accelerating in open loop, then obviously the injectors shouldn't shut off.
Normally, the only time you see InjOn time go to 0.00 and open loop at the same time, is when you are rolling along down the road and you take your foot off the gas. I do see that in your 2025 log and it looks normal. That's Coasting Fuel Cut.
But it does sound like there is some new problem.

Click to expand...

I know few things about ECMLink, I'm not good at it but I understand the basics.

In open loop the ECU is not tracking the O2 for fuel adjustments it's only assuming how much it should open the injectors to get the fuel needed to hit the AFR. In my case this is not happening on deceleration which is normal, it's happening on normal driving and I don't understand why. The same setting were used before and everything was OK, I could drive the car.

I know the SD table need more work but the guy who's been remote tuning the car stopped answering my emails log time ago even though I had payed for a full tuning.

I'll get in contact with Kevin from Six Sigma to give it another try but first I have to fix this fuel pressure problem.

CDgr97GSX said:

That's exactly what I used, too. I had the impression it's a Toyota part, it might be from Mitsubishi, I don't remember but I know I've read on this forum that's the best alternative to the original o-ring. I've tested the pump to about 80psi before installing it and everything was good, no fuel leaks

Click to expand...

I've looked for pics of how that grommet is used in stock setups. Evo 8 and 9 is the one I know of. What I see is that in the stock usage there is a white plastic spacer under the grommet that keeps if from getting pushed down.
I've seen one or two posts in EvoM saying things like "my grommet disintegrated again".
Anyway, I'm not so sure that's your problem, but the Evo fuel pump hanger and large body Walbro install has a lot of the same problems as 2g DSM. So here's some things worth looking at over there.

pic of the stock grommet with the white spacer under it on an Aeromotive 340 pump that had died, from post #1:



pic of the stock white spacer and a grommet being used on a Walbro 450 install, from post #302.
The white spacer was drilled out 13/32" so he could slide it over the outlet pipe of the 450.
This person also says he cut the rubber "insulator" at the bottom in half to make it thinner:



pic of a Walbro 450 install with grommet, but he is replacing the white spacer with 1 or 2 o-rings. Only 1 in the picture but in the post it sounds like he actually put 2 o-rings there. Looks to me like they would hit that other molding on one side if they got shoved down hard, which they do. That seems to me not good, the support should be even all around the perimeter of it. This is from post #1 again.

CDgr97GSX said:

never get steady again unless I release the pressure from the hoses

Click to expand...

Ohh .... Hmm ....

CDgr97GSX said:

In my case this is not happening on deceleration which was normal it's happening on normal driving and I don't understand way.

Click to expand...

Oh man, it would be interesting to see a log like that.

We're on Boost said:

I've looked for pics of how that grommet is used in stock setups. Evo 8 and 9 is the one I know of. What I see is that in the stock usage there is a white plastic spacer under the grommet that keeps if from getting pushed down.
I've seen one or two posts in EvoM saying things like "my grommet disintegrated again".
Anyway, I'm not so sure that's your problem, but the Evo fuel pump hanger and large body Walbro install has a lot of the same problems as 2g DSM. So here's some things worth looking at over there.

Click to expand...

Thanks for all your research posted. I would definitely inspect the grommet once I remove the pump. Theoretically my pump can never slide down from the point where the grommet is because I'm still using the lower locking plate / bracket which it's keeping the pump pressed against the grommet.

CDgr97GSX said:

I would definitely instepect the grommet once i'll remove the pump. Theoretically my pump can never slide down from the point where the grommet because I'm still using the lower locking plate / braket which it's keeping the pump pressed against the grommet.

Click to expand...

Right, the pump won't slide down. Just the grommet could somehow push down. Maybe you will be able to tell if the grommet is out of position or anything weird when you look in there next time.

Since I've never had a 2g, my "eyes" on this thing are mostly from a video that has pretty good clear videography and corny comments from the guy that made the video. Starting here and going for about 10 minutes.
He used one fat injector o-ring shoved all the way into the bellmouth receiver, and another thinner (I think) injector o-ring pushed down over the pump outlet pipe. Didn't cut the outlet pipe shorter. No rubber part at the bottom. Hard to say how good this really worked but he did more video with this car later. Car is a 1996.

On my own car, a 1g, I'm using a turbo basically same size as yours. Fuel pumps are 2 smaller pumps in series. A Walbro 255 intank and a Walbro 255 external inline pump. Good enough for 650 hp on a Dynojet on E60. Same injectors and regulator as you have.
My solution for the o-ring problem is not a grommet or o-rings, it's plain viton tubing, soft (60 durometer), no fabric reinforcement inside it, covering the entire outlet pipe of the intank pump. Exactly like this:


You see, that rubber can't go anywhere.
Unfortunately I can't find a place to buy that particular tubing anymore.
Wish I had bought about 10 feet of it at the time. But I only bought 1 foot.
It was 1/4" ID by 9/16" OD.

BTW it's awesome that you have both an Innovate ECF-1 and an Innovate SCG-1.
I see the raw voltage for both wideband sensors. Looks good to me.
Do you have the rear one way back where the rear O2 is on the stock car?

But if you wanted to switch over to a hose type connection at the top of the fuel pump, instead of the bellmouth receiver with some type of seal in it, you don't have to worry too much about the ID of the AN fittings being too small.
I mean, -8AN fittings are plenty big enough. I'd have to say even -6AN fittings are big enough inside, because my high pressure hose and fittings are all -6AN all the way from the trunk to the fuel rail. But if you go to all that work, you might as well make that first fitting a -8AN if you can, if there's room for it.
-6AN can carry enough fuel, it's just a matter of how much pressure drop there is due to the hose and fittings.
A Hellcat has a lot of pressure headroom when you are only talking about 650 hp.

We're on Boost said:

Right, the pump won't slide down. Just the grommet could somehow push down. Maybe you will be able to tell if the grommet is out of position or anything weird when you look in there next time.

Since I've never had a 2g, my "eyes" on this thing are mostly from a video that has pretty good clear videography and corny comments from the guy that made the video. Starting here and going for about 10 minutes.
He used one fat injector o-ring shoved all the way into the bellmouth receiver, and another thinner (I think) injector o-ring pushed down over the pump outlet pipe. Didn't cut the outlet pipe shorter. No rubber part at the bottom. Hard to say how good this really worked but he did more video with this car later. Car is a 1996.
On my own car, a 1g, I'm using a turbo basically same size as yours. Fuel pumps are 2 smaller pumps in series. A Walbro 255 intank and a Walbro 255 external inline pump. Good enough for 650 hp on a Dynojet on E60. Same injectors and regulator as you have.
My solution for the o-ring problem is not a grommet or o-rings, it's plain viton tubing, soft (60 durometer), no fabric reinforcement inside it, covering the entire outlet pipe of the intank pump. Exactly like this:
You see, that rubber can't go anywhere.
Unfortunately I can't find a place to buy that particular tubing anymore.
Wish I had bought about 10 feet of it at the time. But I only bought 1 foot.
It was 1/4" ID by 9/16" OD.

Click to expand...

I saw a lot of different ways to install the pump, for that moment I thought that is the best way. I wouldn't secure the pump only with clamps, I have the feeling that with the bracket in place and the rubber between the basket and the pump it's the best option. The only thing I don't like is that the pump is a little bit to low in the tank.

I had the same setup as yours before changing the fuel lines and the injectors. The line pump was a little bit to loud and the FIC 2100's were too big for a nice idle. I decided with a rebuild engine it's better to go for a single bigger pump and for FIC 1650's.

We're on Boost said:

BTW it's awesome that you have both an Innovate ECF-1 and an Innovate SCG-1.
I see the raw voltage for both wideband sensors. Looks good to me.
Do you have the rear one way back where the rear O2 is on the stock car?

Click to expand...

I had an AEM before the widening and the boost controller. The O2 sensor never worked good with ECMLink. I had to use a buffer. I switched to Innovate and I got their boost controller too, so since I had an extra O2 sensor I mounted in the rear O2 just to have it to double check the AFR.

Tiki2777 said:

Chrysler kid is right. Honestly, I'm shocked you went through all the effort to weld on AN fittings to the top of the hanger and you kept the worst piece of the design: the nozzle assembly under the hanger. There's almost no way that thing is sealing correctly.

Cut that thing off, weld on a barb that you can couple onto with a hose setup, and that will likely solve the issue.

I.....had different issues with a Walbro 450 setup, but again was using a Fuelab Regulator. One of my trials and tribulations led to ditching it for a Radium Pulse Damper and Regulator Combo, and upping to a 525.

Click to expand...

What are your opinions on the Radium dampener? I was debating on installing one(or two even) but haven't read much on their effectiveness.

We're on Boost said:

Oh man, it would be interesting to see a log like that.

Click to expand...

I posted two logs. In 02.02 at second 138.098 I have 2131 rpm and 6% throttle position and ECU is in open loop, second 138.164 rpm 2166 throttle it's still 6%, idle switch is off and ECU goes in closed loop and fuel flow goes down to 3.3cc/min and injduty goes to 1.9%.

This is one example and I don't understand way the ECU is going in closed loop and why it's cutting the fuel.
I think I'll open a new thread with this problem in the right section.

You mean here?



You fell out of closed loop about the same time your MAP sensor started acting up. Notice how it doesn't react to your changes in TPS afterword and the choppy O2. Perhaps some of this is another defective OmniPower MAP.

CDgr97GSX said:

That's exactly what I used, too. I had the impression it's a Toyota part, it might be from Mitsubishi, I don't remember but I know I've read on this forum that's the best alternative to the original o-ring. I've tested the pump to about 80psi before installing it and everything was good, no fuel leaks.
I do have a re-wired fuel pump kit installed.

Click to expand...

Like this one?



You can get a fuel pump assembly with a 3/8 barb for a neck fitting on RockAuto. If I ever broke the factory slip one I was just going to use a 3/8 barb into the sending unit. You can get them in a 90 for the top and thread them into a straight fitting in the tank

CDgr97GSX said:

I posted two logs. In 02.02 at second 138.098 I have 2131 rpm and 6% throttle position and ECU is in open loop, second 138.164 rpm 2166 throttle it's still 6%, idle switch is off and ECU goes in closed loop and fuel flow goes down to 3.3cc/min and injduty goes to 1.9%.

This is one example and I don't understand way the ECU is going in closed loop and why it's cutting the fuel.

Click to expand...

Oh yeah, like Steve said, your Omni 4-bar quit working right there at 138.034 secs.
Display the raw voltage for it, "RawOmni4Bar". It goes to 0.02 volts at 138.034 and stays at either 0.00 or 0.02 volts all the way until the engine quits running (0 rpm) at 147.926 secs, whereupon the omni starts working again!

Then when you crank to restart it at 173 secs the Omni is still working but only for about 3 seconds, then it dies again.

Welcome to the club! You are about the XXth one to have trouble with an Omni 4-bar. Is yours a "genuine" Omni or is it something else?

Your 2 widebands during that time from 138.960 secs until the restart are reading dead lean but that's probably correct and their raw voltage is full scale 5.0 volts, so I think they are ok.

It might be strange that the Omni resets itself when the engine stops and works for a few seconds when you restart. Don't know what to think about that.

CDgr97GSX said:

I had an AEM before the widening and the boost controller. The O2 sensor never worked good with ECMLink.

Click to expand...

There's a club for that too. Welcome to it!

chrysler kid said:

You can get a fuel pump assembly with a 3/8 barb for a neck fitting on RockAuto.

Click to expand...

Are you talking about a bulkhead fitting? Something like this? Oh that one is aluminum though. Do you have one in mind that you could post a link to?

That Toyota/Mitsubishi grommet can ABSOLUTELY slide down/get pushed off of the barb/nozzle, which is why I abandoned ever fully implementing it-great point (If you fight with it long enough it'll slip off the Walbro 450 style nozzle barbs, which is why I abandoned it altogether).

steve said:

You fell out of closed loop about the same time your MAP sensor started acting up. Notice how it doesn't react to your changes in TPS afterword and the choppy O2. Perhaps some of this is another defective OmniPower MAP.

Click to expand...

We're on Boost said:

Oh yeah, like Steve said, your Omni 4-bar quit working right there at 138.034 secs.
Display the raw voltage for it, "RawOmni4Bar". It goes to 0.02 volts at 138.034 and stays at either 0.00 or 0.02 volts all the way until the engine quits running (0 rpm) at 147.926 secs, whereupon the omni starts working again!

Then when you crank to restart it at 173 secs the Omni is still working but only for about 3 seconds, then it dies again.

Welcome to the club! You are about the XXth one to have trouble with an Omni 4-bar. Is yours a "genuine" Omni or is it something else?

Your 2 widebands during that time from 138.960 secs until the restart are reading dead lean but that's probably correct and their raw voltage is full scale 5.0 volts, so I think they are ok.

It might be strange that the Omni resets itself when the engine stops and works for a few seconds when you restart. Don't know what to think about that.

Click to expand...

Thank you guys for pointing out something I didn't notice. At least it does make some sense now. It's a +10 years sensor, even though doesn't have so much working time.
It's a Mitsubishi style bought it from extremepsi and I used before on stock manifold now it's mounted with an adapter.
I'll look to see what option I have for a new sensor.

A fuel tank adaptor it's 3/8 which is 9.5mm. The inside diameter of the outlet of the pump it's 11mm. This was one of the reasons I didn't mount one. Also using the fitting and connect the pump with a hose and clamps the pump will be lower in the tank.

CDgr97GSX said:

The inside diameter of the outlet of the pump it's 11mm.

Click to expand...

No, 11mm is the OD of the outlet pipe. Depending on where you look, the outlet pipe is either given as 11mm OD or as 3/8" Hose barb. It's made for 3/8" hose. Nobody gives an ID for it.
1g users in here have been putting 3/8" hose on it. Take a look at Marty's pics here in post #278. In the first pic you can see (barely) that the hose says 3/8" and 9.5mm.
He's using a nice AN fitting on top of the whole thing. He's a nut for having the biggest possible hose fittings once you get into the AN stuff. I think he might have used -10AN here. If so it's total overkill. -8 would be nice if you want very large. Because even though the -8 hose ID is kinda overkill, the ID of the various fittings along the way is smaller just like you are pointing out. If you slosh around in that thread I think you will find more info about it.
Thanks for the good pics @1990TSIAWDTALON !

The great beauty of it though is the amount of vertical room on the 1g pump hanger. Just look at it! So yeah I don't know how all this would work out on a 2g. It's so crowded vertically.

CDgr97GSX said:

I'll look to see what option I have for a new sensor.

Click to expand...

In here it's usually agreed that the AEM stainless MAP sensors are the best ones and the most reliable. They are round barrel type.
3.5 bar if you aren't going to go over 35 psi of boost.
5 bar if you are going higher than 35 psi boost.

I've used them both. Lately I have the 3.5 bar on my car because I noticed I was getting spikes on my AFRatioEst plots in the logs. Didn't notice any bad behavior from it though. Anyway there's no spikes with the 3.5 bar.