The AUSubaru.com.au Forums

Hi Guys...trying to understand all this ECU biz in respect of engine management and attempting to get my EA82T running better. It has a flat spot as it first accelerates then its fine, its always been there. The engine is running off an EMS stinger. Now the vacuum line that runs back to the ECU I notice has a little one way valve in it, which way should this be. ??

And the vacuum hose comes from the nipple at the back of the plenum chamber then meanders around through the left guard and then goes back in size a bit for the ecu. Would the length of this vacuum matter or the change in size???? What does it tell the ECU? that there is Vacuum or Boost??

Sorry to load people up with this, but my Brumby has a mixture of brumby wiring, EA82 wiring and stinger harness and its all a bit of a mess. There are three relays behind the lower panel under the glovebox, I don't know what they do but they had a lead for connection to laptop jacked onto them yet there is a connection point on the ECU for a laptop???

Thanks in advance...I'll need some help to sort this out...basically it has the flat spot and then the engine was breaking down under power..I've put new plugs in (it had the iridium plugs fitted) but I just replaced these with normal NGK as per the book till I can get this all sorted.

T.

It should not have one at all!
Rip it out!
Put a filter in instead

Trevor, can you get hold of a wiring diagram for the Stinger EMS ? Surely it is for turbo?
Wonder if you can see if the TPS is connected to the Stinger.

Are you running the dizzy with a pickup in it as in 4 plug ECU style and wires exit under its bum and no vac advance can or guts?

Oh are you using an AFM of EA82T like hotwire or flapper or Stinger using Manifold Absolute Pressure sensor - might explain the vacuum you supply and there may be specific needs for the vacuum source to work correctly.

Surely an aftermarket ECU suits turbo applications

Try to ID your relays by disconnecting with everything off and restart. Guess one is fuel pump, another is EMS power


The EA82T 3 plug ecu does not have a boost or vacuum connected to it but does get an overboost signal to cut petrol injectors I suppose it is, via the doo dad in RHS under bonnet near tower on an L Series.

H-top..sorry can you explain, what??? rip out the vacuum line or the one way valve??

Steptoe, thanks for all that..I am still digesting what you've given me...I found the fuel pump relay once before, its on the strut tower near the engine and another one there was for a water spray system over the intercooler that was triggered by a switch on the throttle body when full noise was applied..

Manual including diagram is here:-

http://www.enginemanagementsystem.com/i ... Manual.pdf

H-top and Steptoe are both indicating that the Stinger has an inbuilt MAP sensor, hence the vacuum line. I think what H-top is suggesting is that the 1 way check valve should not be in there as it is interfering with the MAP sensor. and to fit a filter so as to smooth out the sudden pressure changes that occur in the plenum.
All programable aftermarket ECU's should cater for N/A or Turbo tuning. The question is this Stinger just a piggyback or a complete EMS. And has it been wired, installed and tuned correctly for the application.
Im thinking the flat spot you are getting could be something to do with the check valve or the tuning (read mapping). could even be something to do with fuel pressure reg plumbing.
Im obviously no guru or qualified tuner but I like the challenge these machines present!!

There should be no valves either way on the
vacuum line to the ecu for MAP sensing.

A filter would be appropriate though.

Ok thanks....I'm still learning with all this..cheers..Trevor

I have no idea about the Stinger, but was asking if it had its own MAP sensor inbuilt or aside somewhere not employing Fujis AFM - hotwire of flapper - not wanna give any bum steers.

No worries mate. It reads boost and vac so it
needs to be unrestricted

Ok...I've got rid of the one way valve and run a new vacuum line thru...I've also done a little house keeping under the bonnet and cleaned a few things up. The engine idles beatifully but still has that little cough as you raise the throttle then it powers up. One thing I have noticed is it smells really rich idling away. Also, I can not detect any vacuum leaks. I put my hand over the inflow and totally blocked the engine off at idle. Couldn't hear any vacuum leaks so pretty sure that';s ok. Computer wires under the dash with plug to jack into back of laptop had female end. I have cut it off and engine still runs ok..considering that it couldn't have been mated to a laptop, could it have been for a handset???? Any other thoughts on the flatspot in the engine???? Thanks anybody.....

Possibly tuning mate. Probably actually.

Get a WB02 sensor if possible and check out the
mixtures.

Cheers

ok ...thanks

I know I'm not terribly helpful sorry

hard data is easier to work with

Im even less help (read experienced) but agree with you Sam. Tuning! had a quick look at the stinger thingy on the net and if you can conn a laptop and a mate with some clue about engine managment and tuning, well you could find a quiet street and have a go at altering the mapping in the area of concern. Of course with out a wide band O2 sensor you must be carefull doing this, gradual adjustments as you go.
Seat of the pants tuning shop!!! Save $$$, unless you bugger it up big time...

J

Ok, thanks for the imput from both of you. I appreciate it. I am going to do a fairly lengthy post here to explain what is going on. I own two brumbies. One is stocko and this one has the EA82T. I bought it from Ipswich and is a brisbane car apparently. I'm old school and at 55 years was brought up pre ECU management times. I am trying to understand it and do understand the process in principle. My eldest son has a 13b series 3 RX7 running a microtek ECU and he has tried to help and has been helpful. Problem is that we are looking at something that someone else has installed and along with all the other add on electrics in the thing (elec windows, reversing sensors, shoo roo, keyless entry, alarm etc etc, the wiring is a real nightmare. Also, under the bonnet, wires have been cut and go nowhere, also found wires under the passenger floor like this and removed them.

Now:- I would presume that the ECU is wired correctly or the engine wouldn't start and run....true/false

The computer lead hanging under the dash and hard wired to three relays I am suspecting is not for the attachment of a laptop, but was probably for a hand held controller....prob right??

The local ECU gooruu in Toowoomba wanted minimum of $400 just to roll it into his garage and hook it up to tune it ..with no guaranteed outcome (don't think so)

Now, the motor goes good, feels strong, doesn't use oil, pulls well..just has this flat spot.

If I can get a laptop hooked up to it and see what happens, well that might be the way to go. But if I can't get this engine sorted, then in the long run it will have to go tata's because if I can't tune the bloody thing then its not much good to me. Last time we tried to hook it up to a laptop, the computer started playing music and and the screen asked for a 4 digit passcode. So really, I have to make sure that everything else is hooked up correctly (Vacuum, laptop etc) before I would ask anyone else to try and tune it. Anyway, I shall persevere...

Umm? Sorry to resurrect this thread but I thought I would post an update and just try to sort out a few things...

This car had two vacuum lines running into the dash. One was for the heater controls and the other went to the ECU Stinger. After pulling the dash apart and having a look see, I now have the vacuum hose running from the back of the plenum chamber direct to the ECU so it gets an uninterrupted signal. The other comes from the number one cylinder intake and goes to the heater control and it now has the one way valve on it. So I've basically swapped them about and tidied it all up. It now seems to run a bit better and has lost its flat spot somewhat.

Before this, the ECU was getting vacuum from the number one inlet, with all manner of stuff tapped into the line including blow off valve, boost gauge and boost controller thrown in there somewhere.

I have taken the boost controller out and connected the vacuum line direct again to the turbo...but a couple of questions.

(1) Where should the Blow off valve trigger vacuum be connected....I have it to the nozzle on the inlet on number one but it doesn't seem to be working...

(and) there is a vacuum line that comes around from a fuel regulator..where should that be hooked up to..there was a nozzle between the air filter pod and the throttle body but I plugged that up and hooked this regulator line into manifold vacuum on number one...It seems to be running very rich when it is idling.

Also the three relays I found hanging under the glovebox...Tried to sort what they were but one seem to be something to do with the fuel pump, and the other two for the remote door locking (I think) anyway, tidied it all up and put them back. Car ran OK with them removed except for the fuel pump one, although there is another relay on one of the strut towers that works the fuel pump. I think some of this stuff under the glove box might of had something to do with a hand held for the ecu.?????

Also, bosch distributor cap fitted perfectly and got that sorted thanks everyone. (Love to drive this car one day) (Wife brought down rego sticker for this car to the shed where it sits..there was a little bit said about paying rego for cars that don't go anywhere..they just don't understand))

Trev

Sweet mate.

All those lines must go to the manifold after the TB.

I matters not where though. The plenum would be ideal
and make everything consistent.
And having things Tee'd does not make a huge difference
as it all works on a MAP (manifold Absolute Pressure) system.

It all works the same way as everything pressurizes at
the same time at every point. It's the concept of PSI(pounds square inch)
so it means everywhere!