GordonShek

Heading home tonight on the motorway, doing about 65-70 following another vehicle.

Got bored so I decided to drop a gear, into 4th, and floor it. It went at first, then the KnockLink shot to the top LED and at that moment, I lost power. It must have happened in a split second and after the LED light went back to a single green, I got the power back and that was that.

What happened? Was it overboosting? I've got an EcuTek 3 ECU so i thought the overboosting problem as solved. I had previous overboosting problems in my P1 when I changed for a complete decat exhaust system.

Any advice would be greatly appreciated thanks.

Gordon Shek

wanted

I'm no expert but i'll give my opinion anyway.
If the knocklink went to red then that must mean det and if so then the standard knocksensor probably picked it up aswell, so the loss of power would have been the ignition retarding and the boost dropping, to save the engine, but why this happened is what you're gonna have to investigate.

StickyMicky

my thoughts,
over boosted, cut the fuel, low fuel means lean running = det so knocklink shows top marks

john banks

Two possibilities, most likely first:

1. Overboost and hit fuel cut hence the red light which can happen on fuel cut or rev limiter
2. Detonation which the ECU killed by knocking the boost.

If the second one the cut would be nowhere near as sharp as the first which is a very abrupt fuel cut.

Given that we mapped it when it was a lot colder and it wasn't overboosting it is more likely you have oil in a restrictor or solenoid pipe which will need cleaning out, or a leak in the pipework to the actuator for example.

Can you tell me what boost it is peaking and holding at present and we'll take it from there?

GordonShek

I'm not sure what it's boosting at as I haven't got a boost guage!!!! But I think I can get the info from the rolling road data.

I was nowhere near the rev limit, think it was about 4/4.5 K RPM. The road conditions was dry and at night, so therefore it was quite cool (typical late summer's evening).

I can only drive the thing and the above statement flew over my head so fast I didn't even notice it!!!!

Cheers

Gordon Shek

john banks

Rolling road data from a previous test is not helpful to tell you about a new problem which is happenening on the road now (and a further RR test would not be useful either as it will make less boost on the rollers than on the road). What you need is a boost gauge.

Hitting overboost fuel cut (sounds like you did) OR hitting the rev limiter both can cause the red light to come on on the knocklink. Since it was midrange it is therefore more likely to be overboost. Is it a very abrupt cut like your previous fuel cuts?

What I am saying is that if it didn't fuel cut when we mapped it in far cooler weather then it is less likely to be due to the ECU map, and more likely to be due to a maintenance issue with oil clogging the boost control pipework. This can and does cause overboost on a standard or modified car and is common. Pipework splits can also cause this, as could a sticky actuator and other causes.

If you could tell me readings from a boost gauge and were able to clean/check the hoses and there was still an issue I could tweak the map to sort the overboost for you.

Alternatively if you want to bring the car over to me I can clean all the hoses out for you and check the actuator and check all the hoses for leaks, and this would I expect sort it. If it does not then I can tweak the map to sort it.

A Subaru dealer may not be very understanding since they would think your car was running rather too much boost for standard... which indeed it is.

GordonShek

Cheers John

Thanks for helping but I don't know when I can make it up to your neck of the woods. I'm currently out of a job and therefore have no income so therefore have to sell the car.

S&S Services have offered to sell my car on behalf of myself and would post it on the "Approved" subaru list (as if the car was one of their own and can provide finance, warranty etc).

The rest of this post is sent to your email account.

Thanks

Gordon Shek

john banks

YHM