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EA82T Masters: Help Me Fix One Small Issue...SOLVED!! read last post


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38 replies to this topic

#1 garner

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Posted 27 July 2004 - 06:36 PM

I've mentioned some of this in some other threads but thought I'd start fresh.

Heres the situation....

Set Up

EA82T
Delta Cams
Light Flywheel
TDO4 Turbo
WRX TMIC
WRX BOV (recirculating)
WRX gutted down pipe to 2.5 to "turbo" cherry bomb muffler


Everything else, ignition, fuel delivery, etc is stock. disty to ported vacuum, FPR to manifold vacuum. Timing set to about 23 degrees, disty advance seems to work just fine...

The issue

Starting from a dead stop, I must sort of "launch" to get going. It will tolerate a gentle, traffic sort of take off, but with the flywheel and TDO4, the launch is the thing that get's you moving. It's hard to avoid breaking loose as I'm only RWD at this point, but Breaking loose in a brat is so much fun anyway.. :headbang:

So I accelerate in 1st, boost comes on, reach full boost power, oh the power...Hit about 6000rpm and shift

Clutch, Let of Gas, shift to 2nd, let off clutch stomp on gas and here's where things get weird... Sometimes, not always, but sometimes I hit what feels like the overboost fuel cut. Just like hitting a wall, no power then all the sudden, power, oh the power....

Does not seem to happen shifting into other gears, atleast I haven't experienced it yet. I haven't taken it onto the free way to really accelerate 0-60 yet.

I can't quite determine the exact combination of things which have to be in place for this to happen but I am leaning towards thinking that its when I drop the gas pedal, as in remove my foot completely as opposed to just letting off part way to make my shift.

This is not turbo lag, it's a hard fuel cut feeling type of power loss.

I need a co-driver to pay attention to the vac/boost guage and the A/F meter (which is hard to read in the sun).

Generally speaking, the A/F meter wanders quite a bit, I don't know exactly why...

What do you suppose causes this?

-Is the stock fuel system not able to keep up at times?

-Is the stock FPR not doing what it should (when I suck on the control vac line the pressure drops, when I blow, it raises) I don't remember what the exact readings are but it was within spec of the FSM...

-Is it me, I mean the way I'm driving? As I said, I can't absolutely confirm this but it sees to be mor eprone to happen when I really let off the gas pedal. I am always going for a quick shift between 1st and 2nd and not so much between other gears

Would it make sense that if I let completely off the gas, the throttle body shuts rapidly, vacuum goes up, fuel pressure goes down and when I shift and try to accelerate, the Fuel pressure regulator can't compensate and correct fast enough?

Any and all ideas, hair brained or otherwise would be appreciated. It's a totally functional set up right now but I want perfection.... And I can only imagine what this would do to my trap times....

thanks

garner

#2 WJM

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Posted 27 July 2004 - 06:52 PM

when I take my GL-10 past 6k and then shift...it does that...going to 2nd, and 3rd. Dunno why...try to shift around 5500 and see if it still does it.

I know that mine hits something like a rev limiter around 6200-6300...and when i shift and gas it again...same as you decribe...except a little softer like a rev limiter.

My solution was to shift at 5900 or before. Then it doesnt do it.

#3 garner

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Posted 28 July 2004 - 11:37 AM

No theories on why it would behave like this?

Anyone like the fuel pressure regulator theory? Like the rapidly closing throttle creats a vacuum spike and as such fuel pressure drops rapidly and once it needs to raise again, it is one step behind....

Come one guys help me out with some "theories" or "ideas"

At what point will mods outrun the stock injectors? Doesn't really seem like they are my problem at this point but just curious. Does anyone know the specs of the stock injectors? flow rate, etc?

bring em on (ideas that is)

garner

#4 WJM

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Posted 28 July 2004 - 11:45 AM

did you try my shifting mod?

the FPR....sounds like a valid idea, but then agian, it woudl do it at lower shift points too...right? or left?

#5 garner

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Posted 28 July 2004 - 12:05 PM

wjm,

Yes, it seems lower shift points sort of make it go away but it really seems tht it's the speed at which the gas pedal is released and reapplied.

In a quick shift at nearly any upper rpm (under boost) it will often do the lag/fuel cut/hit a wall thing.

If the shift is more "normal city driving style" and there is 1-2 seconds between "off the gas" back on it, it is less likely to happen (I couldn't get it to happen last night anyway)

This is tolerable and something I can live with but if I'm going to smoke ricer Hondas, and pull high 12's on the 1/4. I can't have this kind of thing happening.....

So, on a technical note. I know the stock FPR lowers pressure under vacuum and raises it under boost. Do after market, adjustable raising rate FPRs do the same or do they just raise under boost? If they just raise under boost, I bet that would solve my problem...

garner

#6 WJM

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Posted 28 July 2004 - 12:17 PM

install something in the line to lower its reaction time...??

#7 garner

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Posted 28 July 2004 - 12:30 PM

hey there subaru parts guy,

can you look up the fuel system parts and see if there is any kind of check valve or something in the vacuum reference line?

Your idea is a good one, I will study my FSM vac diagrams and see if anything is indicated on the reference vac line

I got most of my stuff for this swap in boxes :banghead: Twas a bit of a battle to get it all figured out and back together. There is a good chance there is something I don't have somewhere in the system

I did a we bit o' surfing to determine the operation of after market RRFPR's it seems as though they do just raise under boost, don't lower under vacuum (that seems like a fuel economy device to me, lean out the mix at low power cruising) like the stocker

garner

#8 WJM

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Posted 28 July 2004 - 01:12 PM

I dont see anything in the line...a new FPR lists for 140...if you want, i can get you a new one for 105. There are only 13 left in the country....

Oh, this is interesting...it only lists two injectors...1985 only for the MPFI...and then it only lists 1985-1990 for turbo...so it looks like 1986 and up turbo and non use the same injectors....except for XT tho.

29 of those left....can get for 96 each.

Anyhow....sounds like...I know, try disconnecting the FPR return line, and plug it off (on the FPR too of course.)...and see if it still does it.

#9 garner

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Posted 28 July 2004 - 01:26 PM

I know, try disconnecting the FPR return line, and plug it off (on the FPR too of course.)...and see if it still does it.


Thanks for looking into the info mecca for me...

You talking about the fuel return line? or the reference line?

What about this, run the FPR reference vac hose to the waste gate line so that under boost, it will raise pressure but would not lower under vacuum????

It's so funny what Subaru wants for thier parts. I found a bargain MSD adjustable RRFPR new for $45. It's not the fancy billet, AN fittings etc. Much like the stock unit but adjustable (base pressure, not rate of rise)

garner

#10 Subarutex

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Posted 28 July 2004 - 01:29 PM

Stock the FPR references the manifold pressure. You could try referencing the throttle body pressure. This however will probally make the car run richer while in vacuum.

The spider intake has 2 vac. ports on the TB. I'd try tapping into one of those and see if the problem lessen's or goes away.

#11 Caboobaroo

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Posted 28 July 2004 - 01:50 PM

hey man, if ya need someone to help read your a/f gauge and your boost gauge, I'm right up the road sorta speak;) I got today and tomorrow off from work or Friday-Sunday after 4 so I could come on down and help ya if ya like:D I soooo wanna see this beast in person!!!

#12 garner

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Posted 28 July 2004 - 01:57 PM

hey man, if ya need someone to help read your a/f gauge and your boost gauge, I'm right up the road sorta speak;) I got today and tomorrow off from work or Friday-Sunday after 4 so I could come on down and help ya if ya like:D I soooo wanna see this beast in person!!!


caboobaroo,

Thanks for the offer, I might take you up on it. I'm pretty nuts crazy busy this week and next but I do want to make sure I get this sorted out by the WCSS. Btw, you going to have the minitruck brat there or....?

garner

#13 Free Range

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Posted 28 July 2004 - 02:26 PM

I like the FPR idea garner,
I used to have very simmilar problems at high rpm shifts in 1st -> 2nd, with RRFPR set at ~37 doesn't do it much, and at ~45psi never, but thats running plenty rich.

as a side note, there is a definite power gain when the fuel pressure is cranked up, not sure what the max flow into the injectors versus RRFPR psi is, but doitsideways, a while back I think, was saying that ea82T's wouldn't stay together for competetion rallying unless he had the fuel pressure up around 45-50psi, so I say crank up the fuel at least a little. Others have said the stock fuel system stayed well within safe bounds @ 14psi and above, but more fuel = cooler combustion and power... yeah turbo, yeah

-nels

#14 garner

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Posted 28 July 2004 - 02:49 PM

hey nels, how goes it?

I was just talking with my buddy here at work and he thinks I might be one to something. Here is what I am going to try tonight.....

Hook FPR vac reference line to a t in the wastegate control line. This is the only point in the systen that I can think of that never sees vacuum (maybe a very small amount but not much). I think this will make the stock FPR behave like a RRFPR until I actually buy one of those.....

This could be a good thing as it would keep the pressure up more directly realated to boost and wouldn't lower with the vacuum pressure spiking....

I'll report back on my finding

keep em coming

garner

#15 Subarutex

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Posted 28 July 2004 - 03:08 PM

the ports on the TB also never see vac. I mistakenly hooked my boost gauge and BOV up to one of the TB ports the first time. Car ran kinda wonky :) And the guage never showed Vac!

#16 garner

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Posted 28 July 2004 - 07:17 PM

the ports on the TB also never see vac. I mistakenly hooked my boost gauge and BOV up to one of the TB ports the first time. Car ran kinda wonky :) And the guage never showed Vac!


Oh man, I'm confused, I thought the TB ports increased vacuum with engine speed while mainifold went from vacuum at low revs, and negative vacuum at boost ? ? ?

So with your RRFPR, where do you have the reference line pluged in, Manifold or Ported?

garner

#17 nutt7

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Posted 28 July 2004 - 08:59 PM

this idea may be dumb, but you said any ideas so here goes...try pulling the return hose from the bov and plugging it at the intake, so it blows to atmosphere. this should take 'x' amount of air out of the equation between shifts and upon the 1-2 shift you will start out a little more rich, due to the maf thinking there is more air in there...this may help determine if it is a lack of fuel problem.

sound plausible?

#18 suberdave

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Posted 29 July 2004 - 12:19 AM

i had the same prob with my ea-82t, when i opened up the intake between the IC and the TB, i thought more air more power... wrong, 2.5 inch chrome pipe did not do the trick.

i hit fuel cut at about 5psi at 3500rpm in 2nd gear, 1st worked fine.

i 86ed the 2.5 inch chrome intake and went with a 1.5 inch intake, now works awesome.

think about it i am running 11psi boost, right, you dont need more air volume. you have the turbo pushing it into the cyl. as long as there is pressure on top of the valve, thats all the engine cares about.

when you hit fuel cut the turbo never looses boost, the fuel gauge dose not drop or spike (trust me i had a gauge taped to my wendsheld driving down the highway), and i put a noide light on the injector and ran it into the car, never went out.

just my two cents after long time messing with it,

hope it helps some...

-=suberdave=-

#19 rallyruss

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Posted 29 July 2004 - 01:08 AM

dont forget about spark quality and delivery. An ignition miss may feel similar.
leave the fuel presure regulator alone untill you can see what the o2 does under the conditions described.
also rember it will show incomplete combustion as lean. a bit of a false reading.

#20 garner

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Posted 29 July 2004 - 12:50 PM

Nutt, that's actually a pretty good idea as a test. I had it vented to atmosphere for a while but re plumbed it while solving a couple of other issues. It sure sounds cool for a Brat to make that whooshhtt sound on each shift. I might try that atleast to see if fuel is the issue.

Suberdave, are you sure that the size of the IC to TB pipe was your issue? On the Spider intake TB the intake is 2.5o.d. (or metric equivelent) Is your stock TB smaller? How did you wire your light to an injector? I was thinking that having injector status lights would be helpfull and a good safeguard from having one freeze up and lean out / melt a piston? Does the light pulse with the injector or does it just indicate that there is power to it? When I was troubleshooting some earlier issues I was trying to figure out a way to determine if the injectors were working, I couldn't be sure that I was hearing them. ended up pulling them out of the manifold and watching them spray gas all over, not a good idea but it did help me detemine that two were not working....

Rallyruss, Spark is wicked good (accell hasn't' blown up yet (28 miles and counting!!)) and plugs look about perfect a little towards rich. Thanks for reminding me about the A/F falls lean indication. That really takes extreme richness to occur right ?(I read something about it some where). I'll try to get my better half to go for a ride with me tonight.

You don't suppose the 5 gallons of 110 leaded race gas I put in my first tank of gas would have f'd up my O2 meter in 28 miles do you?

garner

#21 rallyruss

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Posted 29 July 2004 - 01:43 PM

Spark is wicked good (accell hasn't' blown up yet (28 miles and counting!!)) and plugs look about perfect a little towards rich. Thanks for reminding me about the A/F falls lean indication. That really takes extreme richness to occur right ?(I read something about it some where). I'll try to get my better half to go for a ride with me tonight.

You don't suppose the 5 gallons of 110 leaded race gas I put in my first tank of gas would have f'd up my O2 meter in 28 miles do you?

garner


Ahh another Accell. mine did not fail right away either. It started cutting out on hard pulls up hills undr boost. a jerking sensation that would go away if I took my foot out of it reducing the load. this got worse and worse untill it finally dies on a road trip. I was sure I must have been leaning out under load. but no it was just that POS coil. I point out the the o2 mixture reading because it will look like its lean when you have a misfire condition. rember O2 means all it reads is how much 02 is in the exhaust stream. and lean and misfire both let tons of o2 into the exhaust.

I dont know what leaded fuel does to an o2 but it cannot be good.

noid lights are verry common for testing injectors. the usually plug in to the harness where the injector connects.unfortunately they only tell you that some kind of signal is being sent to the injector. they can get you in trouble if you use only the noid to diagnose. Avoid the noid.

I would bet that a good stock coil will solve your problem.;)

#22 garner

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Posted 29 July 2004 - 02:15 PM

Ahh another Accell.


didn't even think about that, I will try the stock EA82T coil that I have, I assume it's good... we'll see if it makes a difference.

garner

#23 WJM

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Posted 29 July 2004 - 03:01 PM

My accell of 1.5 years pulls strong 4k to 6k.....there is this strange stumble around 3k to 4k.

#24 WJM

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Posted 29 July 2004 - 03:11 PM

Uhhhhhhhhhmmmmmmmmmmmm.............

22433AA041 1985-86 TURBO & MPI IGNITION COIL

Maybe there is a reason that item is $99.98.......but i can give the USMB the pice of $79.98. Still too much for me.... :eek: NONE in the country.

22433AA140 is the 87-94 turbo.
And...well...its...uhhmmm....well...15 in the country...i dont think they are going anywhere at $193.18 USMB cost. :eek: :eek:

Maybe I could switch to a stock one? and it would go away?

#25 rallyruss

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Posted 29 July 2004 - 03:46 PM

Maybe I could switch to a stock one? and it would go away?



I think there is a reason the stock coils cost so much(besides the crazy dealer price)

and accell coils are cheap? hmm

you get what you pay for?

this may not be the problem but I would start there as a coil is easy to swap.




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