I'm going to send my injectors to injector dynamics for testing and also might modify my secondary ffe rail to thread in a dampner.
will it matter where in the rail it's physically placed?

 

Rather than trying to modify the FFE rail, why not just get one of the inline Radium FPD's that can/will just attach to the rail itself?

Fuel Pulse Damper, Inline Kits

 

good idea I might just do that!

 

Alternatively, CJM makes a secondary rail with a built in FPD port.

https://cj-motorsports.com/products/cjm-secondary-rail-13b-rew

Originally I ran the FFE primary and secondary rails, I converted over to the CJM rails earlier in my current build, they're sexy as hell. Now I'll be going with the inline ones I linked earlier. I'm swapping to those (because apparently I hate money) due to getting a Pro Jay Sniper intake and completely abandoning all the OEM injector ports.

 

o nice those though look good. I ordered the inline from radium. going to try and put in on the entry of primary rail
if this fixes my issue I will lose my $hit
I have spent so much money time and headaches on this issue

 

tuner seems to think issue might be around 2.5ms on primary injectors. wants me to send Injectors to INJECTOR DYNAMICS and see if their is an issue with flow at that milli second range

 

yes we have hopefully fixed that issue with a boost leak. we wont know properly until we find lean issue on mine

 

hey have a look at this I found online. it could be the issue. poor grounding of engine to car. im using the factory rx4 ground so il get a bigger one made and add another to it.

3,000 RPM Hesitation Fix

 

That is a fix for the stock ecu. The FD doesn’t have the best grounds but that most likely isn’t the fix in this situation.

Dale

 

I had a strange hesitation at 2500 rpm years ago. For me a piece of rubber from a fuel line had found its way into the secondary rail. It obviously caused other issues but a strange hesitation at exactly 2500 rpm was the most obvious byproduct. Did not figure it out until I blew the motor and was disassembling the engine 😞

 

o man that sucks. sorry to hear. I just don't know anymore. I might also throw the stock map sensor back on to my 4 bar map sensor as well

 

injectors came out perfect after cleaning. sad part is they never tested the before. so just gotta install them when they arrive and hope for the best!

 

issue fIXED!! ripper!! i put a radium fuel pulsation dampener on the feed end of the primary fuel rail. it worked. runs mint! i used a an6 90deg fitting, and a an 8 orb tee with 2x an8orb-an6 fitting. screwed the fpd to tee then put it all inline. give that a go buddy hopefully it works out for you

 

man thats awesome I'm glad to hear. tuner suggested secondary rail but I wondered if i should put on primary instead

 

Primary makes a lot more sense to me than secondary. Once the secondary is providing fuel, there is a lot of fuel flow with primaries open. While the secondary injectors are closed, a lot of the time the primaries are just slightly open, and fuel pressure variation makes a lot more difference in % fuel flow when injectors are just slightly open

 

yes that's what we worked out that when secondary's kick in it clears. it showed a small variation on the log when we logged it. another way to test i was told is to plumb a fuel pressure reg in front of primary's on a tee an blank the outlet to see if the gauge moves. i just went straight to the fpd and it worked for me. full boost is now kicking in around 2500-3000rpm. better than the 4700rpm i had. this is how i done it

 

i really appreciate the fellow up. giving me motivation.
i got the inline one so once I get injectors back in I'll see what I have to do

 

this is how I have mine setup going thu primary rail. also have a vac source t'd into fpr like they suggested.
I hope the 4 inch distance from fuel rail doesn't make a difference but they say it shouldn't. they being radium

 

hopefully that works. if it does im wondering if its ffe fuel rail design fault?

 

the fuel pulsation issue has been discussed before, it seems to be more apparent with larger secondary injectors. I'm using CJM secondary rails with R35 FPD in my build but I'm long ways from being ready.

 

I hope it works too I should know in about 2 weeks. I'm also waiting for my rebuilt alternator to arrive.
ya idk its the first time I've heard of this and what throws me off is so many guys use the same setup!
but why me have an issue so I never thought it could be the dampner (if it is indeed that).

 

this is after servicing of Injectors. they didn't do a before sadly but they said they didn't look like they would have caused an issue before

 

well update finally got it back together today. still seems to be doing same thing.
idk what else to do.

 

I also have 1050 and 2000 injectors. 1050s are primaries. As the secondaries come in and their duty cycle is below about 4% the affect on AFR is generally going lean but it is somewhat inconsistent in different rpm / map ranges. This was when the fuel map is setup with a nice smooth incline gain for rpm / map.

This characteristic will move with the staging placement, that is if staging is setup for lower rpm / map position then the lean spot happens there, if higher, then lean spot is higher. I attribute these characteristics to the dynamics combination of these items; inconsistent injector fuel delivery at low duty cycles, wall wetting affects, air flow and pulsation dynamics based upon engine speed.

I have chosen to position staging lower just as boost begins. When trying to correct this with normal fuel map adjustment based upon O2 target control, the cells near that rpm / map range of staging were becoming ~10% higher than the nearby cells. I choose to re-address the problem using the NSP Stage Flow Percentage feature and I forced the secondaries to come in just a bit early and ramp up to 3%. I've been able to get wide band readings to follow the target paths, generally with less than a 0.01 lambda drift. There still is a slight hump, or fat spot, in the fuel map of the staging locations but it is generally less than 2% above the smooth incline desired.

So this was my long winded way of suggesting to see if the problem is happening at the inclusion of the secondary injectors. I have a log window setup where I look at the avg injector duty cycle of primary / secondaries to see when the secondaries come on and how long they stay at low duty cycles.

 

problem seems to be only under primary injector. secondaries aren't even come on at this point yet.
I think even if i just rev it in idle to the rpm it would lean out if i remember correctly
and would require like 10-15% more fuel to reach the demanded afr