eyecandy

iTrader: (19)

Here is the setup, we are running new fuel lines from the pump to the rails, all 3/8" or -6 AN fittings/hose, 550/720cc injectors, PFC w/ Banzai racing base map (apex is too rich/poor timing) , fresh rebuild with a large street port. The fuel pump is a Holley 255 (basically same as Walbro). The lines from the pump are 3/8" with -6AN fittings and hoses to the rails, out of the secondary rail to the Aeromotive Fuel pressure regulator. The OEM FPR is set at 34-39PSI at idle, the most I can get out of the Aeromotive FPR is 20psi (vac connected) 24-25 (vac line open) the gauge is a Holley, anymore the car dies, the AFRs at that pressure is around 11.8-12.1:1 for idle. The enigine idles well at 850-900rpm.

Has anyone had issues adjusting the pressure on the Aeromotive unit? Faulty FPR or Gauge to blame? Something else?

Thoughts, opinions??

arghx

iTrader: (3)

I have 720/1680, 6AN fuel lines (not from the pump back though, just to the factory hardline), and a Banzai Racing adapter for an FD PFC.

With the key in the on position and the engine off, jumper the yellow fuel pump check connector on the passenger shock tower. Can you adjust the fuel pressure to 40psi now? That's how I adjusted mine.

If you then start the car and it won't idle like that, you need to retune the car. It's probably not a mechanical problem unless there is a faulty FPR (never heard of an Aeromotive FPR going bad), or a bad gauge (certainly possible). Personally, I had to completely retune my Banzai Racing basemap--not because Banzai Racing basemaps are somehow bad, it's just that they aren't always going to match your setup (injector flow rates, porting, etc). If your car idles great with really low fuel pressure (again assuming your gauge and everything else isn't bad) then that was just a coincidence. You can't expect to boost the car safely with pressure that low. Most people run 40psi base pressure.

With my large streetport I found the PFC needed a lot more fuel and timing for a good idle than a stockport car, especially when I switched to 10 heat range plugs (I'm guessing you are still running 9's). You can't set idle timing (PFC ignores it) with the PFC controlling idle (as in, idle speeds set to anything other than 0 in the PFC). Do you have a datalogit? Do you still have your BAC valve? If it comes down to it and all else has failed, set all three idles to zero in the Datalogit to have manual control of the idle. That disables the idle control circuit and allows you to control the idle timing.

With manual idle control at 850rpm, I am currently running idle timing of 20 degrees leading and 23 trailing (3 split). Others have had success with negative split, but that's not something to be messed with without experience. If I were you I would start with 16 degrees leading. At the same time you will have to adjust the throttle stop screw to adjust the amount of air entering the engine.

here is a writeup on the Power FC on a 2nd gen which discusses a number of common issues, and has a pic of the stop screw if you've never played with it before.

http://www.geocities.com/arghx/PowerFC.FC3S.Tuning.doc

Banzai-Racing

iTrader: (11)

Firstly this is not our product, we were just helping him out with a map. This is the reason we do not like to just hand out maps. We get blamed for your inability to tune or set up your car properly. You have 550cc injectors, reset the PFC to default settings, there is no reason why it will not start and run.

Secondly as was noted in the email All vehicles are unique and require individual tuning.

SirCygnus

iTrader: (1)

first things first. you have to understand that the thing needs to see vaccume. find a good source for vacume. second, the nipple's threading tends to leak sometimes.

HAILERS

Stock fuel pressure at idle on a stock turbo or non turbo (FPR) is 28-32 psi. IF you remove the vacuum to the FPR, the reading on turbo or non turbo should be approx 37-39 psi.

Seems your engine isn' t pulling much vacuum at idle.

eyecandy

iTrader: (19)

arghx, Thanks for the link I wiull have to read it over. No the car does not start when set to factory FPR, I can adjust it to as high or low as I want, but will only run on about 20psi.

Banzai-Racing, I was in no way saying your base map was bad or blaming you for an issue with the fuel pressure regulator. I do understand I need to tune to my specific needs, your map was the only one that allowed the engine to idle. I thank you for that. This thread is to figure out why the FPR cannot be adjusted to factory specs. Resetting the PFC to the factory map floods it....

I do know I am getting too much fuel, by why FPR is set to minimum and INJ map is pretty damn lean and still seeing low AFRs.

The FPR is seeing a good vac connection, as for the idle is look good too me on a fresh rebuild, 350-400mmhg (IIRC), been running maybe 2hrs tops,

Banzai-Racing

iTrader: (11)

You need to set the fuel pressure at 40psi base and work from there. If you don't then the injectors will not be operating any where near what they are rated at. Most injectors flow ratings are based on 3bar of pressure

Are you sure that you have 550cc injectors in the primary positions? I have seen more than one person that thought that the lower rail was the secondary.

Are you sure that the harness is routed properly? Again I have seen injector connectors on the wrong injectors more that once.

Are you using resistors for the 720cc injectors? Where did you solder them in? what size?

Does the fuel system maintain pressure after you turn the key off? IF so how much and how long? If not then it is bleeding off somewhere. Teflon tape and wire from stainless braiding has many many FPR failures.

Silverfc88

iTrader: (7)

Is this a brand new FPR? Which way are you turning the top key to bring the fuel pressure up?

arghx

iTrader: (3)

for what it's worth, my Aeromotive FPR never held pressure once I turned the key off, but I never had any problem with fuel delivery once I got all the tuning straightened out. I've heard of other people's FPR also not holding pressure once the key turns off. It might depend on the model you have or something.

Check all the mechanical and electrical stuff that has been suggested to you. Set the base pressure to 40psi. Then if it still doesn't run at that pressure you need to do what I call "brute force tuning." You will have to basically tune most of the fuel cells in the car by trial and error. It is very tedious and time consuming but it works. One way to do that is with the datalogit software set to Auto Update.

Start the car and keep your foot on the gas to keep it alive until it gets close to operating temperature (tuning the cold start adjustment table doesn't work well when your car won't even idle hot). Set ghost and map tracer on in the datalogit menus. Gradually let off the throttle and note where it begins to stumble and die. Watch your wideband display and adjust a 3x3 block around your idle cell area up or down in the INJ map. If you are too lean (let's say leaner than about 13:1), increase the values. If you are waaay too rich (it would probably have to be in the 9's to not even idle) then reduce the number there.

The other option is to go into the commander's diagnostic mode (INJ/IGL/IGT mode under settings). The changes you make here will not last once you turn the key off.

Banzai-Racing

iTrader: (11)

^
All FPR's are supposed to hold pressure, if it doesn't then you have a problem, that is all there is to it. When the key is turned off it will drop to around 30ish and hold pressure for close to an hour. It will still have pressure 5-10 after the hour.

SirCygnus

iTrader: (1)

mine does the same thing.

maybe the FPR is faulty? did you try and use a different one?

eyecandy

iTrader: (19)

I know the fuel rails and injectors are correct 550 primary/720 secondary. The resistors, I am not exactly sure what type they are, they came with some plugs I purchased, they look the same as the ones in the rx7store kit http://www.rx7store.net/product_p/extremefuel.htm I think they are the TMC-25 3ohm 1% are these correct?

The resistors are wired near the injectors, few inches away. I am not sure if the secondaries are the problem, as they would not be onoline during the idle...

I am positive the plugs are correct on the injectors, but it never hurts to check them out.

The FPR is brand new, I just adjusted the fuel pressure to 40psi, turn the fuel pump off it dropped to 30psi, after 5-6mins it dropped 3psi (to 27), after 30mins it dropped 4psi (to 23psi). Adjusting the FPR for more pressure is clockwise, less psi is counter clockwise, is that right?

What are you saying about teflon tape and stainless steel wire causing failures with FPR? I have teflon tape on the vac nipple and the gauge, -AN fittings on the fuel lines.

I had limited time today, so tomorrow I am going to check some more stuff out.

Thanks for the help thus far!

Banzai-Racing

iTrader: (11)

Your FPR is functioning perfectly fine. Clockwise is more pressure, that is correct.

boost_its_what_for_dinner

get a new gauge end thread

HAILERS

Fuel pressure is maintained in the fuel rail by two items, when the pump is turned off. One is the FPR and the other is the check valve in the fuel pump. IF you have an aftermarket fuel pump, I'd suspect that item, or if you have a aftermarket FPR I'd suspect that. Both suspect.

eyecandy

iTrader: (19)

Lack of fuel pressure or fuel pressure dropping off is not the problem, its how low the fuel pressure has to be to get it to idle/run.... I am boggled by it.

Banzai-Racing

iTrader: (11)

Do you have the lines routed correctly? Supply --> primary rail --> secondary rail--> side of FPR --> bottom of FPR --> Return line

I was just thinking that if you had the FPR before the primary rail (like you would with a carb) then you would be restricting the fuel to the engine, then by reducung the fuel pressure you would be letting more fuel by allowing the car to run. This of course is the wrong way to route the fuel for fuel injection.

It might be a lot easier if you would post up pics of your engine bay and fuel system. This is obviously a fuel issue.

eyecandy

iTrader: (19)

Everything is wired, plumbed up properly.... I adjust the FPR to 35-40psi, still seeing way to much fuel. I have to lean it out from a base fuel map of 1.000 to about .850ish just to keep it running, and it is still on the richer side. .850 sounds way to lean to me... I have another set of 550cc injectors (came from the same motor) I think I may swap those in and see if anything changes, but I doubt it, they were all clean/tested, the ones in it flow the best of the 4.

Yea so its definately a fuel issue.............

BTW anyone have an issue with the waterthermo sensor? The temps read from cold start to 87C, then pretty much stops there. This is with twin 11" Spal fans running constant on the back, I will stop it for min or 2 and it does not move, I am going to plumb a gauge to cross reference.

arghx

iTrader: (3)

^ maybe your car is just maintaining the proper temperature? Otherwise, the factory temperature sensors (air temp and water temp) are a little slow to respond. You can trigger your fans by triggering a relay from PFC/FD pin 3D, which switches from +12V to ground when it is time to activate the fan. The temperatures are set in the datalogit. It's hard to say without the car in front of me.

How much vacuum is the engine pulling on the mechanical boost gauge? What PIM value are you in at idle according to your logs? In other words, what cells in the fuel map does the car idle in? Other questions: what MAP sensor are you running? What altitude are you at? MAP sensor configuration can cause all sorts of problems.

From what you are describing there is still a good chance it just needs the Power FC tuned/configured. I had to add a crapload of fuel to my map to get my car to idle, even though I have 720 primary's. But then I had to pull a significant amount of fuel from some FD's with 550cc injectors that I have tuned. You need to wire your wideband's analog signal into your datalogit box. Then, post a log of your starting, warmup, and hot idle, making sure to log Advance and Auxiliary under the Monitor window.

Btw, if you don't have a datalogit you need to either A) buy one or B) take it to a professional. You are not going to get it working well with the commander alone. It's just not going to happen.

Banzai-Racing

iTrader: (11)

He has a datalogit, that is how he loaded the map we sent him.

It is a FD map sensor.

87C is normal operating temperature, it is a good thing that it is not climbing higher than that.

Take the fuel out of the correction map, then recalc the base, this is all part of tuning your car. Leave the 550's you have in.

Mills

iTrader: (1)

So you're saying if the fuel pressure drops to nothing quickly after shutting down the regulator is bad? Mine has always done this and had a cold start problem but runs fine otherwise. I also hear it knock like crazy sometimes but I thought that was just because of it being mounted up high on the firewall.

Banzai-Racing

iTrader: (11)

The regulator has an issue, or the bypass in the pump is too weak to hold pressure, or there is a leak somewhere. Any way you that look at it, it is not something that you want happening.