Hello, I have been running turbo for a couple of months now on my 1999 Eclipse GS. My complete install list for my first kit is - Treadstone exhaust manifold, dump tube, Garrett T3 turbo, Tial 38mm WG, Treadstone FMIC, HKS SSQV, TurboXS MBC 7psi, Synapse missing link, Vortech 12:1 FMU, and a Walbro 255 pump on stock injectors. Car ran great!
When installing the FMU I made a mistake and removed the stock FPR. I ran this way for some time. But only now I get random detonation on WOT. Sometimes car boosts great others times not. I realized what to do on these forums (thanks guys) and followed the right setup for my FMU. I installed the stock FPR back in but no result.
Is it possible something is failing? A T3 setup at 7psi w/ a Vortech 12:1, Walbro 255, and stock injectors should not detonate right? Im thinking maybe injectors but Im a lil lost now.

stock injectors at 6psi are pushing it. 7 is over the duty cycle's capability IIRC. What fuel press are you running during idle? should be 45psi for stock injectors

I'm going to be running pretty much the same setup, with exception of ML (running electronic FCD instead) and the brand of MBC is different (Hallman pro). I was under the impression that stock injectors were fine up to 8psi (and some people have reported to be ok at 10psi) with a 12:1 FMU.

What I'm curious about is whether or not the OP is using the high pressure model of the Walbro 255 or not. For the insane fuel pressures our car sees at over 4psi or so (which is over 100psi fuel pressure), you NEED the HP version or you won't get enough fuel. That could be the problem. Also, was the fuel pump rewired like in the wiki? If you're not getting enough current it won't be operating at its best.

The FMU really just sucks, its a cheap way to forced fuel into the motor. I had horrible luck with this setup and couldn't keep the car running good for nothing. You need a WBo2 to really see whats goin on with your motor. How do you know it knockin? Or is it just missfiring from lack of fuel.

IMO if your going to spend the money for a turbo setup, spend a little bit more and get a good fuel system. a SFMU and some 310cc injectors will be perfect for your car.

Originally posted by SilvrEclips
IMO if your going to spend the money for a turbo setup, spend a little bit more and get a good fuel system. a SFMU and some 310cc injectors will be perfect for your car.

precisely

I think its detonation and not knock or missfire. It sounds like a spray can shacking. Im going to hook up a fuel pressure gauge after work today and get a reading for you guys. Thanks for all the help so fast by the way. New fuel setup my be the answer.

That does sounds like detonation. Get that fixed before it takes out a piston

To clarify on my fuel pump as well, I have the Walbro 255lph OEM and not the 255lph HP. I am now guessing I should have purchased the high pressure pump and not the 255 oem. We'll see what the fuel pressure is tonight I hope and go from there. I'll be under the hood of my dsm later lol.

what plugs & wires are you running and at what gap

420aGreen.....your full of shit on so many levels its not funny.

you can run 8psi safely on stock injectors with a FMU. 6 psi is no where near "over dutying" as you put it.

I would check your fuel pumps ability to maintain fuel pressure above 90psi. then i would verify the operation of the FMU.

Next check the heat range of your spark plugs....stocks should be fine but depending on the air temp and the elevation of where your at the stockers might be too hot.

Lastly i would quit listening to this idiot ^^^^^^.

you're right terry. I apologize. Why aren't you a mod again?

Try being a nice guy and you may get somewhere in life. I'm done talking to you and don't appreciate you being a digital gangster hiding behind your computer screen.

Take this into consideration. When using a basic calculator, which terry might not know how to use, lets say you're making 250 at the flywheel (hp). Having said that, use corbin's simple little calculation tool, available on the wiki terry. http://www.2gnt.com/?d=How_to_Choose_Fuel_Injectors

using a low BSFC of .5 which is very forgiving, it came up with over 310 cc which COINCIDENTALLY is what hahn offers and recommends to use with their stage 2 kit which is about 8-9 psi. 8-9 psi is about 260 at the flywheel with a street tune.

Since he is NOT at stage two, lets say his flywheel HP is about 200 at 6psi. WELL, we do this all over again don't we terry. Here, do it with me. Get a pen/paper terry. Take 200 x .5 x 10.5 = 1050. Now, take that number and divide it by the # of injectors which is, 4. you've got about 260cc. Since 190cc is not very close to 260cc, it poses a fuel requirement concern. I'm not sure at what duty cycle stock 420a injectors reach, but i'm sure from testing it proved to be ok to use up to 5-6psi.

read this too terry: http://turbosystem.com/auto/engine/injectors.htm

i'm glad you're not a mod anymore. Be nice to people, it pays off more than you think. Take some prozac. http://www.prozac.com/index.jsp

Yeah you definitely should be using the high pressure pump and not the OEM. Good call on the spark plugs as well.. I know the stock plugs are NGK BKR6ES-11's. With NGK plugs, higher numbers mean colder plugs and lower numbers mean hotter plugs. You need a heat range colder up to 10psi, from what I've read. So make sure you have NGK BKR7ES-11's installed. Not sure about how to gap them.. I need to look into this for my setup, as well.

BTW if you do go with larger injectors as some are suggesting, you will need a way to lean it out when you're not boosting, like a S-AFC. Or your car is going to idle like shit and consume a lot of gas off-boost.

Actually you do not want the -11's. Use the NGK stock number 6097 or I think they may have made a replacement with the same specs.....I read somewhere the 6097 was superceded by a newer NGK plug.

Originally posted by 420agreenvilleSC
Blah blah blah

I think you need to go read all that yourself. your not understanding what your reading obviously.

Hahn has a lot more credibility than you as well.

http://www.turbosystem.com/auto/eclipse/eclipsestage2.htm

and I am not an ADMIN becuase I chose to step down.

420aGreen - The problem with using corbins fuel calculator is that it doesn't apply for his setup. That would work if your using a 1:1 regulator that maintains the same fuel pressure in relation to the manifold pressure. Since this setup adjust fuel in pulse width you can calculate the correct size injectors.

Now on his fuel system he is not lengthening the injector pulse width at all, he is just increasing fuel pressure so much that it forces more fuel out. So there is really no way to tell how far the injectors will go bc there are so many variables in this setup. The only way to know is just to test it out and see what happens. And this setup has been proven to 8psi many times.

Alright! Got a fuel pressure reading now.
Idle FP - 90psi - Boost gauge reading -20HG.
First Gear Pull - FP 70psi - Boost 7psi.(Detonated)
Second Gear Pull - FP 75\80psi - Boost 7psi. (Small detonation)
Third Gear Pull - FP 80psi - Boost 7psi. (No detonation)

How do these numbers look? Should be much higher under boost I'm guessing, like mike said over 100psi FP. How is the idle at 90psi FP? Gotta get a dam Walbro 255 HP on the way.

As far as the plugs go I'm thinking they are the stockers. Guessing those are fine unless the NGK 6097 are better then the -11's. They come pre-gapped right?

no the plugsd are all about heat ranges. Look at the plugs and look for the line on the electrode. you want the heat line to be right where the electrod bends. You also do not want the porcelain to be bright white, you want to be able to see a "ring" somewhere in the porcelain. If the porcelain is very white then your too hot. The outer thread portion that is exposed into the cylinder will give you an indication of idle ratio.

90psi at idle.....thats wrong, somewhere you getting the wrong measurement.

At idle your FP should be 45~50psi. Remember your FMU is a 12:1 so for every 1psi of boost your raising fuel pressure 12psi. 5PSI (boost) should net 60PSI of fuel pressure(on top of base pressure). Therefore the base pressure of 50PSI + 60PSi raise = 110psi at only 5psi boost.

7PSi of boost should net +84PSI. Therefore 50PSI Base + 84PSI raise is 134PSI of fuel pressure.

Now you need to keep in mind the fuel pumps ability to raise pressure that high. the Walbro 255LPH (GSS317) will top out just after 100psi. I think last time i tested mine it ran to 110psi.

Now the 16g used by hahn with that fuel pump and a 12:1 FMU has proven to work regardless of what links Mikey wants to post. Apparently some things never change.

Remember that the larger turbo you run, the more fuel you need. in other words 5psi on a 16g is not equal to 5 psi on a GT30R. so anything over 5psi should be carefully done.....your doing that now so good work. I dont see the size of your t3 turbo, most true T3's are pretty small. Hell on a T25 you can prolly get away with 10psi on your setup, wont be any faster though!

You appear to be having an issue with fuel pressure for one. either the 12:1 is not actually a 12:1, meaning it could be a 10:1 8:1 6:1 ect. You also may have an issue with your fuel pump.

The spark plugs will give you a lot of detail. They will indicate where your lean (high or low), wether or not your too hot of a range, fuel mixture at idle, preignition or detonation (you can have one or the other or one leads to the other).

If you have a magnafying glass, look at the plugs for alum imbedded into the porcelain cathode. That is the only proof you have detonation. Pre ignition will feel the same to a driver but is not nec detonation.

Didn't anyone catch that he put the stock FPR back in?

Take it out.

He needs to leave the factory reg in there with a standard FMU. you remove the reg with a SFMU only.

Really? My bad.

I ran the stock inj 12:1 setup for 2 years with no problems up to 8psi, and that put out a pretty solid 12:1 AFR, dipping to 11.5:1 at times. The whole reason the FPR works is volume flow, ~220 cc stockers @ 100psi will flow about the same as 330's @ 45psi, both max about 205 hp under ideal conditions. Bump the 220's up around 110, 120 psi you can get close to 220 hp, maybe 8 psi tops assuming 10 hp/psi, but like above mentioned that the 255 can max at 100psi, so keep an eye at high rpm/boost. Should be fine up to about 6k. Your pressures are all jacked up, as mentioned above also. the 12:1 shouldn't kick in unless there's positive atm reference, and it just 'clamps' the fuel after the stock FPR. Take the 12:1 off for now and get your oem stuff working properly, them make sure you have all the connections proper on the 12:1, as well as verifying you don't have a torn disk.