mrmonk7663

iTrader: (9)

Need a little help. I have a 99 stock ECU car. Egr removed. Charcoal canister removed. Fuel vapor canister removed.


Do I still need the two sensors my fingers are on? One is a hitachi boost sensor and it connects to the other one? I thought these were for the emission system only but want to make sure.

Second question. Can I remove the fuel pulse damper on the fender well with the stock ecu? Anecdotal accounts seem to say yes but I don’t know myself. The car will stay “returnless” but will get an MS3 in the future.

Id like to remove this junk from both my 99’s and my 02 if possible to clean up the area further. I don’t know if the vcts or vics is somehow tied into any of the stuff I want to remove or if there are some kind of issues that will arise other than a CEL. (Obviously the fuel damper doesn’t) CEL doesn’t matter...I have plenty from egr delete and charcoal delete.

Thanks for any help. Hope y’all had a good Easter.

Savington

iTrader: (31)

Deleting the fuel damper is a bad idea.

mrmonk7663

iTrader: (9)

Can you elaborate a bit? Since the NB1/NB2 cars also have a fuel damper on the fuel rail I’ve read about many folks on here deleting it...but never with a good explanation honestly. I’d like to understand why it’s bad (your reputation proceeds you so I trust your judgement)

Ted75zcar

iTrader: (2)

+1

OEMs don't put unnecessary parts in critical systems like fuel delivery. The returnless design has characteristics that make the damper important.

Ted75zcar

iTrader: (2)

People love the ~delete~ and then say "it works" when the car still functions. They rarely understand the impact.

If you were to delete the damper and the monitor the fuel pressure (at high speed and resolution) at the rail over the entire RPM band, I promise you would put the damper back on.

mrmonk7663

iTrader: (9)

Fair enough guys. Damper delete idea is scrapped as of now.

Now, any input or information on the 2 sensors I mentioned? Appreciate everything!

Blysccr

Sorry I can't add to the sensor delete questions.

@Ted75zcar when you get MS3 and if at that time you go returnless, are the dampers still as crucial? Or is that when they can be removed?

Ted75zcar

iTrader: (2)

return or returnless?

Blysccr

my bad. going from returnless to a return style, are the dampers still necessary?

Ted75zcar

iTrader: (2)

If you are going with big injectors, I say yes, but one at the rail is probably good enough.

My 850cc IDs will resonate on a return style system in a couple different narrow RPM bands without a damper.

DNMakinson

iTrader: (3)

Interesting. When I went return style, I did pull the inlet damper. The outlet is damper was replaced with a FPR from a British NB. Running FF640's. @Ted75zcar do you think I could have some funny imbalances? Could they cause a single cylinder to lean at certain conditions? Did it show up in fuel pressure testing only, or in the form of an ugly spot in the VE table? In other words, should I plan to add the inlet damper back as a matter of course, or could I detect the need? I would have to go to pick and pull and get a replacement unit.

@mrmonk7663 The Boost MAP sensor you will not need. However, if you wish to use barometric pressure compensation with your MS3, that is your sensor right there. The other one I am not sure what is / was, but it is gone from my car.

Ted75zcar

iTrader: (2)

I did not notice issues return-style without the damper on stock blues, 265 tan tops, supra green 305s, or the RX7 440s, but I may not have been sensitive to the signs.

This is a hard thing to instrument. It can manifest itself as an aliased signal during autotune. IOW, if you have the table breakpoints set right to catch it, and a decent tune outside of the VE table, you will see odd discontinuities/peaks/valleys in the autotuned VE. The phenomenon was super narrowband on my setup (ID 850, stock return style hard-lines, AEM afpr, m-tuned rail, -6 lines,... that is what I remember). The lower resonance was like 50-100 RPM wide around 1000 or so, and then there was another one up around 4800 IIRC.

fundamentally, you aren't getting the correct base pressure when this happens. Req fuel is calculated from the base pressure, you do the math

I wasn't setup then like I am now for knock detection. Knowing what I know now, I can almost guarantee you would see a higher likelihood of sparse knock and EGT imbalance when this is occurring.

I would pull/post the data, but it is buried on a BU drive several TB ago, if it exisits at all anymore. We had a catastrophic failure on that PC where we lost everything that wasn't backed up.

DNMakinson

iTrader: (3)

I’m tending to think I’m Ok. The only funny thing my engine does is show a high knock signal on cylinder 3 at 6500 RPM. It does that no matter what level of MAP I’m running. I think it is a mechanical thing. I see no AFR anomalies.

Plugs don’t look like knock is real, and pulling timing does not change this (as well as the aforementioned Manifold pressure.)

Feel free to let me know if you see thins otherwise.

Thanks, DNM

Ted75zcar

iTrader: (2)

~shrug~ it is possible. You might be able to test it out if you have an AFPR. Adjust the base pressure a little bit, which should change the resonant frequency. Change req-fuel to match and see if the mystery knock rpm moves at all. IDK.

mrmonk7663

iTrader: (9)

Thanks for the senso info. I’ll take it off the naturally aspirated car and leave it for the boosted ones.