Could do with some help and guidance regarding the ablove.
Few weeks ago my car went into limp mode.
Did the re-set through disconnecting the battery and brake route and that fixed it.
Went away for a long weekend and drove around 450mls, this was a casual weekend away so nice cruising speeds.
This trip took the engine through the running in mileage so couldn\'t resist giving it a bit of squirt - boost cut at 5k.
I\'ve checked the waste gate moves and not stuck, so I guess I need to fit a proper boost gauge to see if it\'s overboosting.
Today it dropped back into limp mode, some 500 mls after the last time.
Went back to it 30 mins later and it had cleared itself, but only for a bout two miles then limp again.
Got home and left it for 2hrs took it out again fine, thought I\'d see if the boost still cut out - it just paused for a split second at 5k and again at 6k - decided that was enough.
Could these issued be related, better still what the hell do I do now?
I\'m trying very hard to love this car but it hasn\'t been a happy couple of years so far.
John
just side tracking on this , you say "running in mileage" have you had it recently rebuilt ?
Yes - Rebuilt be Carl, 1400 miles on the rebuild.
Any reason for asking or just interested?
I didn\'t realise that you had had a rebuild that\'s all
I would prob speak direct to Carl to be honest
Is it the stock ECU John?
If so it would be worth getting the ECU error codes just to make sure what the issue is. There are a couple of things that can throw the car into limp mode, not just boost cut.
As Prof says, Check the error codes and see what the car is throwing up. Hopefully something simple to fix. There is a write up on here of how to check the error codes if your not sure.
Ade
How do I get the error codes.
Do I need someone with a specific programme on a pc to plug in.
As far as I know it\'s a stock ecu
Thanks for the help so far
Not sure but I think our FC\'s are ODB1 and will still provide some basic code data when you plug in a tester. Almost any garage will have a tester, luckily I live with JREX who has a state of the art SnapOn reader
Take it to a local garage John and share the codes on here
I have never even seen the ODB port on our cars .. where is that hidden away ??
This is how I pulled the fault codes of my FC
You\'ll need to use the FSM for some of this. http://www.rotaryheads.com/PDF/2nd_gen/
To see what fault codes the car has stored. You\'ll need an analog multi meter to read the pulses from the ECU. Down near the battery and leading coil pack there are two green connectors. Ground the single one to the negative on the battery. Then plug the multi meter into the larger connector. One of the connectors is ground (top middle) then top left is positive and that is the ECU fault output. The bottom middle point is to test another control unit. Once all connected up turn the ignition on. Multi meter will display 3 second pulse then it\'ll display the fault codes. 1 long pulse is 10 (2 long pulses is 20) then you\'ll get short pulses, 1 pulse is one (5 short is 5) that code would = 25. The FSM gives all the fault codes in fuelling the part.
I\'ve never needed to fault for codes on an FC but I was making the fair assumption that there is a port somewhere that will provide ODB data, and at the very least some CAN data. Upon doing 2mins of research online I came up with this..
"That\'s the easiest way to run diagnostics on the FC. The S5 is simple, just ground the green one pin test connector up by the leading coil. Then turn the key to the ON position. The check engine light will illuminate and then go out. Then it begins to flash the codes. A long flash is a "10", a short flash is a "1". It will flash any stored codes and then begin to repeat itself. To clear the codes, either disconnect the negative battery cable or pull the BTN fuse. "
This is from RX7 Club and so is North American, hope it works but says S5
and our cab\'s are S5\'s. Now you just need to interpret them with workshop manual or an electronic version on the net. I\'ve got workshop manual so I\'ll do my best to help..
For security I\'ve been pulling the EGI fuse overnight, this can\'t be having any effect can it?
Ring Carl before anything
The problem with euro S5\'s is they don\'t have a check engine light in the warning light cluster, like the US car do. So you\'ll need an analog multi meter to pull the codes.
Quote from: Mazzyrx7;859772The problem with euro S5\'s is they don\'t have a check engine light in the warning light cluster, like the US car do. So you\'ll need an analog multi meter to pull the codes.
An LED works to - the code output comes out on a pin that\'s an \'open collector\' output, so the led needs to go between battery positive and the code output (oh and use a 12V led as it has the resistor in it).
There is no ODB (I or II) for these cars - the ECU is just too old!
But we are assuming John is running a stock or chipped ECU and not an aftermarket jobby
As you will remember I believe Pete rewired the car.
What numbers are on the stock ecu and is it in the footwell like the FD
Quote from: johnf;859779As you will remember I believe Pete rewired the car.
What numbers are on the stock ecu and is it in the footwell like the FD
N374, N380 - something like that - if it\'s any number combo like that and has 3 yellow connectors then it\'s a stock or chipped ECU so the error codes can be read as above.
Looks like a stock ECU N380
I have an old one from my FD and that has exactly the same numbers.
Had a look at the car yesterday and the first thing we noticed was that the lambda sensor wire wasn\'t connected anywhere.
fitted it as per picture - is that the right connector?
How would you expect it to run without this connected.
Couldn\'t make much sense trying to get error codes so decided to see if this makes any difference first.
Also fitted a boost gauge so I\'ll take it for a run later and see what it\'s doing.
The car will run fine without the stock lambda sensor - it will throw an error code, sometimes 2 - but these are for the lamda and \'feedback\' errors that will be generated by it not being there.
Unlike most cars that rely on the O2 to control idle, the FC doesn\'t - it only ever uses the O2 to control the closed loop portion of the map which occurs on cruise and light load. Anyone who has ever connected one of those LED AFR meters to the stock lambda will know exactly when this occurs - as the led display \'bounces\' back and forth when it\'s working in this mode as the sensor constantly adjusts the ecu to rich and lean alternately - averaging out a near stoich combustion. This occurs between about 1200 rpm and 3000, but never under WOT conditions or heavy load, and not on idle or warmup either.
If you run the car with the lambda disconnected it will use fixed maps that mean it will ruin a tiny bit richer than normal, but the car will be quite driveable. You will not get any fuel cut or boost cut from no lambda.
Couldn\'t make a lot or sense out of trying to read the fault codes but it hasn\'t dropped into limp mode again.
Fitted a boost gauge, Apexi, that reads in Kpa which I\'m told is a similar scale to Bar.
I get boost cut at a reading of .75ish.
If the stock boost is .55 I am overboosting.
As far as I know the car is pretty stock apart from a cone air filter and I changed the
exhuast back to what I believe to be stock boxes.
So in laymans terms what are the common causes of overboost and should I just look at
fitting a boost controller or try to find out what\'s going on.
Would fitting a boost controller just be a way of getting round an issue I ought to solve?
Also been suggested that I change the oil metering pump as this could be the cause of
both the limp mode and boost issues.
Any thoughts
Thanks
Hi John try using a fuel cut defender! As this cured my boost cut when I put a straight through exhaust from turbo back & induction kit, as it tricks the ecu that it\'s only boosting to its std boost around 7.5psi when it\'s @ about 11psi with no probs @ all. Or I have a old style hks fcon ecu £100 posted that came off my fc with harness so it\'s plug n play , all u need to do is get it remapped!
Over boost is caused by the exhaust being to free flowing over the stock one John.Simple cure is a restriction in exhaust to make it flow like a stock one.
Default will be 99% you need a good used oil metering pump.
The two faults are not connected as boost cut does not cause ecu to go on default.