KEVWRX95

I'm hoping someone can come up with an answer to my car as I'm getting fed up with spending money on it and still having problems, therefore I could be close to breaking it and selling everything off as the missus is starting to talk about divorce !!!!!!!!!!!!!!!!!!!!!!

My car is a JAP WRX 1995...........However thats where it finishes.....mods are
2.5 STI engine
Lightened flywheel
MD309 turbo
Pace front mount intercooler/ radiator
Fast road Cams
Uprated fuel pump
Uprated fuel filter
Parallel fuel feed
550 injectors
FSE fuel regulator and gauge showing 3 bar of pressure
HKS dump valve
Equal length headers
HKS exhaust (no cats)
oil catch tank
NGK 7 SPARKPLUGS
Tesco 99 fuel
Gems ecu/ antilag.................................. I think thats it

Right the running problem I have is that whilst driving along at normal speeds 20/30/40 mph my car constantly hesitates and kangeroos as if its about to stall. so I push the accelerator a little more to get the car through it....and of course the car then takes off hitting boost, so I have to back off...........so I look a right tit when driving along.
The strange thing is under boost the car seems to drive alot better until I get to the three figure area (private track) then at about 120mph my car starts to hesitate again and my knock link lights up so I have to back off. GRRRRRRR

Now I have already put in brand new NGK 7 sparkplugs and gapped to 0.7mm,
and it still kangeroos. Therefore I am now having to think about coilpacks.I only bought this current set about 18 months ago. I really don't want to spend another £250 on coilpacks if this is not the reason my car is ****.

I was aways under the impression coilpacks break down under boost, not under normal driving which my car seems to do, therefore can anyone out there confirm that coilpacks can still affect your car under normal driving???

Or can anyone give me direction to look elsewhere to what my problem could be..................I have checked pages and pages on scoobynet to see if anyone else has had similar problems, but all I find is problems with coilpacks under boost !!!!!!!!!!!!!!!!!!!!!!!!!!!

Thanks for reading
Kev................................well fed up................soon to divorce.

VAL113R

would it not be better to get someone who tunes Gems ecus to have a look at the car. I am sure if they plugged their computer in they could look at what the car is doing under certain conditions of driving.

they might not be able to fix it but they could tell you what needs done

KEVWRX95

Thats exactly what I did a month ago. however strangely the car performed perfectly for the day and got remapped from 1.3 bar upto 1.5 bar.
And I thought the gremlin had been dealt with, but within days the stuttering started again..thats what is doing my head in.it seems to ba an intermittent fault..........................however over the last couple of weeks it does it every day
Would I benefit from going to a rolling road venue where they can put my car onto a machine and whilst driving, it may show the problem I am having ???????????????????????

Cheers everyone
Kev

David MY99

Sound like the mapping/fueling isn't done properly.
could be also an air leak which make's it off boost run a bit lean.

KEVWRX95

Cheers for the replies,
What hoses should I check for air leaks then ?
Would that explain the car leaning out and feeling as if it is about to run out of petrol ?

Should I also be looking at the crank sensor, or the cam sensor ?
Would they also effect the daily driving of my car ?

One other slight thing I've noticed today when driving, my revs stick at 2000 and I have to put my foot under the accelerator pedal to get them back down to 1100 normal idleing, could this be connected to my problem or is this just something else going wrong ???????????????????????

Keep em coming everyone
Kev.

mark@wrx

I can tell you exactly what it is. Its the GEMS anti lag, god knows why you need it on a road car!
Anyway, its the same as my mates group n car. Basically, to run the ALS properly, the revs need to be at a ridiculously high setting to achieve full instant throttle. IE you have no part throttle. So there is an idle air cut put in to keep the revs down. Hence, I assume that your car keeps seeming like its hunting all the time and only revs fairly smoothly once hot.

Just out of curiosity, did you do anything to make the brakes work properly when ALS is switched on? We had to take off the servo assist on the rally car and the pedal is solid all the time.

SOLOUTION: Get the ALS taken off it!

KEVWRX95

Mark
Now you mention it, when my car is idleing the rev counter does go up and down a few 100rpm.like it is hunting, just like a faulty MAF would do.
Is that what you mean?

The only BUT is..........I had the GEMS/ANTILAG done back in November 04 and didn't have any problems until a couple of months ago, so how would you explain that???


Also ,although I very rarely use it I do like the anti-lag (I really don't want to lose it )

Kev

mark@wrx

If your car is using the MAF then something is wrong as GEMS doesn't use it or the lambda sensor! I would get in touch with Steve Simpson if I were you as he's probably mapped more Scoobs and Evos with GEMS than anyone else.

KEVWRX95

Mark
Sorry maybe I wasn't clear, I don't have a MAF as you quite rightly say the GEMS does away with it, I was trying to explain how the car pulses when idleing.

I also wanted to ask as mentioned in my earlier post would the anti lag interfere with my car at high speed, ie hesitating and knocklink lighting up at anything over 100mph ??????

Cheers Kevin.

mark@wrx

Shouldn't do. I'd get it checked by a decent mapper!

strongman

WHEN YOU HAD THIS MOD DONE,DID YOU HAVE YOUR FUEL ,AIR FLOW AND TIMEING RECALIBRATED FROM A 2 litre TO A 2.5 litre.

Jolly Green Monster

iTrader: (4)

It has been mapped for the 2.5 and then mapped again recently by me.

It was perfect when mapped, the problem at 120mph appeared and I found it was boost related and then found the vent from the 3port boost solenoid blocked.. unblocking it solved the 120mph problem and all was then well.

If the throttle is sticking.. you can resolve the 2000rpm problem by pulling the accelerator up then it must be mechanical.. the cable is catching etc.. try greasing / oiling the cable.. this could be the on off throttle judder at slow speed as the cable is jolting between part throttle and no throttle and sometimes sticking.

I would try regapping the plugs to 0.5mm if the miss at 120mph goes then you can say it is spark related and then get new coil packs.. if it is the same as what it was doing initially then it didn't seem spark related. It could be boost solenoid related though, worth cleaning out with brake cleaner.

Antilag was definitly off when mapping and then we tried it after iirc..

Happy to check it etc.. drop me a line so we can organise when if you like.

Simon

KEVWRX95

Cheers for the replies guys,
I will clean my boost solenoid today, and grease my throttle cable, and see if that makes the slightest difference first............................

I really dont want to take my spark plugs out again if I can avoid that job !!!

Kev

KEVWRX95

Well, checked the boost solenoid, that was all fine, greased the throttle cable,.........................and nothing has changed.

So I am thinking now it could be two things.........either the coilpacks, which I still doubt as they're only 18 months old...or the air idle valve.

The reason I am thinking this is because at idle, I believe my car hunts up and down only 100revs or so, so if the shutter inside was not shutting properly or the signal to my Gems ecu was not correct this could cause excessive air getting in......which would explain when driving normally rather than being shut completely it is leaking air in therefore causing my car to stutter as the mixtures are out.................and then at the top end 100+,the excessive air leaking is causing det and severe hesitation ???????????????

What does anyone else think ????????

Kev.

Jolly Green Monster

iTrader: (4)

I would regap the plugs before changing coil packs..

Happy to give it a check on the laptop and wideband Kev FOC of course.

Simon

KEVWRX95

Hello Simon
I was just saying to BRYAN today I may have to contact you and organise a meet.....going onto the sparkplugs....I remembered the old ones were actually gapped around 0.6mm, so when I put the new ones in at 0.7mm I thought if the car is worse then I know it is the plugs, however the new plugs didn't make the slightest bit of difference either way????????????

Kev

Jolly Green Monster

iTrader: (4)

I would say that it would take a fair bit more than 0.1mm to make them worse but 0.1mm may improve if you see what I mean.

I could be totally wrong but I think it is worth eliminating them but trying 0.5mm.

Simon

KEVWRX95

Re gapped to 0.5 no difference

I phoned Subaru Gatwick to find out a price on a new AIR IDLE VALVE, firstly because at the end of the day mine is now ten years old, so I'll start there.........as previously mentioned my coilpacks are only 18 months old, so I will probably try that first, then if no difference, it will have to be coilpacks, and if that doesn't work......I f*cking give up.............................my only saviour is I'll try to organise a meet with Simon to plug in his laptop to maybe give me a clue ????????????????????

Kev

500 views and no other input from anyone

jaytc2003

iTrader: (1)

just my 2 cents, but have you thought about changing the hks dump valve to a standard recirc type? When I first got my car it had one on and I had hesitations at times (not kangerooing though) I adjusted the bolt on the back of it to tighten it up a bit and that helped, but i then switched to a standard recirc type and its been fine ever since.
My car spec is nothing like yours though (one day maybe!!!)

skywalker

Sounds like you found a small point in the map that might be a tad bit lean. What RPM's does it happen at? What is your estimated throttle position? How much vaccuum are you running when you are driving at this point? What gear are you in?

If it is consistent then it is probably in the map, if it seems to be in different places I would guess a vaccuum line while cruising.

You should be able to see this with a wideband pretty easy.

Cheers,
William Knose

Jolly Green Monster

iTrader: (4)

I would agree but it was intermittently doing it before the remap.. remapped it and no problem and then it reoccurred and got more frequent is my understanding of the situation.

There was a very slight on off the throttle judder but nothing that couldn't be put down to it being MAP based ecu control but it is alot worse than that now according to Kev.

The dump valve is a reasonable idea.. try blocking off vac line to it so it cannot dump and see if it still does it.

See you next Wednesday for a check up anyway Kev.

Simon

SPEN555

Just a thought.

Is there anyway the GEMS Ecu could have lost the map you did Simon and reverted to a default or the old map?

Jolly Green Monster

iTrader: (4)

Cannot see how..

I have a copy of the map here and can compare it with the map on Wednesday that is in the car..

Will see I guess

Simon

KEVWRX95

Tightened the dump valve completely up, and went for a drive............................................a nd it didn't make any difference

One other thing my car does since I have noticed my problem is the car starts first time every time from cold no problems..............however when I drive down the road so the car is only half heated (showing on my temp gauge in my car) for instance, to stop for petrol, when I try to start it, it turns over and over..........................whether I leave the throttle or I pump the throttle it does not fire up.

I leave it a few mins, just as if you may have flooded it, and then with a bit of throttle blip it finally fires up. It never use to do this before !!!!!!!!!!!!!1

Does this mean anyhting to anyone ?????????????????

Cheers Kev.
PS See you Wednesday Simon, Bryan may be there !!!!!!!!!!!!

Jolly Green Monster

iTrader: (4)

Was it like that immediately after the remap which was what 7weeks ago now? or only when this problem reappeared / got all the time rather than intermittent?

You just described the Crank position sensor failure.. you could try cleaning it and the cam position sensor whilst at it.

cam position sensor is below the oil filler neck, undo the 10mm bolt holding it and unplug the electrical connection and lift out.. clean the cylinder with a rag and white spirit or brake cleaner etc.. the crank position sensor is identical only between the pulleys on the front of the engine.

Simon

KEVWRX95

Simon
I've already taken the crank sensor out and cleaned it, a small amount of black dust/grime was on it. I will go and do the cam sensor now.can I just ask is the cam sensor the same cylinder shape as the crank one ? and just by cleaning the outside of the cylinder how does that make any difference as I imagine the important sensor bits are inside the cylinder, therefore if one of these is knackered how would you know ????????????????

Lastly if the crank sensor does cause your car not to start properly, does it also effect the driving aswell..........like my symtoms ?????????

Kev.

Andy McCord

it will throw up a CEL also

Jolly Green Monster

iTrader: (4)

No CEL on GEMs and unlikely to throw a CEL on OE ecu until totally gone and won't ever start.

The usual symphtom of a failuring Crank sensor is failure to warm start.. my understanding is that the sensors are magnetic and slowly get less magnetic etc..
the dirt that builds up on them whcih they should work through becomes a problem as they get weaker.. removing the dirt revitalises them for a period. But all this is on the OE ecu. It is possible the GEMs is more sensitive etc..??
We can try the cam sensor from my car next week if everything else seems fine.

Cam and Crank sensor look the same only I think one is brown and the other grey or they might both be brown.. but yes clean the cylinder.

The warm start problem is the usual symptom but also misfire as the ecu doesn't see the crank or cam rotation and so doesn't spark / injector fuel..

Simon

KEVWRX95

Thankyou for all the info Simon,
I'm sure I'm not the only one learning a thing or two, I have cleaned the cam sensor now....................again it was a little grimey. Yes both are cylinders.

My car is now in the garage for the night.I am at work tomorrow 40 mile round trip, I will see if anything has changed ?????????????

I'm assuming the crank and the cam sensor's are original, again 10 years old, so maybe they do need changing ????????????????

I'll ask Subaru prices for both tomorrow, I imagine they have to fax the request again for the part number and price.(like the air idle valve I asked after)

Cheers Kevin

Andy.F

Just a tip - If you just block off the vac line to it then the dump valve will open when on boost and target boost will not be achieved.
I don't see how a VTA dump valve would have any effect on a map based ecu under vacuum conditions ?

Andy