Hi all, I'm new to the forum and Scoobies, just picked up a 98 Turbo (totally standard) and have a problem with a slight loss of power from around 2000rpm. The check engine light came on and was showing knock sensor fault. Had the knock sensor replaced, no more check engine light and it pulls better but the problem is still there. I've cleaned the injectors, replaced the plugs, again i noticed a slight improvement but the problem is still there.

It starts and idles fine but when it gets to 2k feels like you are just feathering the brake pedal every two seconds. it's only a small fluctuation but really annoying and is most noticable when on the motorway, feels like you're constantly lifting off and on the throttle. I'm wondering if it could be a dirty sensor or a dying fuel pump? Any suggests would be greatly appreciated!

 

did you erase the fault code of the ecu when it had the problem

 

I don't know, the garage replaced the knock sensor and when i got it back the check engine light no longer came on (it was intermittent before i had the sensor replaced). Is it worth doing an ECU reset? I assumed the garage would reset it.....

 

yeah think the ecus log the fault untill it cleared try a reset and go from there

 

These type of symptoms could be anything.

You haven't mentioned MAF - could be that(?)...

 

Never assume, it makes an '***' of 'u' and 'me'

Reset the ECU as per here, take note of any codes flashed and the end of the procedure.

 

i know, it could be so many things..... I've considered the MAF but a lot of people say it has trouble starting and idling with a faulty MAF. I've no problems until 2000rpm. I disconnected the sensor with the engine running and it stalled, which i understand can mean the MAF is working correctly. It takes a purple label MAF so it's around £300 for a new one

I'll try an ECU reset when i get home from work tonight.

 

TBH mate, that procedure is a myth, a load of bollox and proves nothing.

It's a good starting point.

 

Wow, I reset the ECU last night and it's worked! Apart from getting some strange looks by driving a mile down the road then getting out and messing with the ignition so that it looked like i was stealing it, all went to plan. It ran flawlessly to work this morning. I noticed a slight blip in revs at 2000 going up a steep hill but how the car drives has been completely transformed. Thanks for everyone's help, I really appreciate it.

 

Give it a little time you can still have an issue there, the ecu now has to re learn, if the problem has gone then sorted but if its still faulty then it will come out again

Tony

 

Right, understood. I'll keep my fingers crossed in that case. I really hope it's fixed though because it was phenomenal this morning

 

My 00MY UK Turbo 2000 did this when I filled it with BP Ultimate andwhen the wife filled it with 95 RON. What petrol do you use?

 

Huh, that's interesting, I've just been filling it with 95RON. Did yours stop doing it when you changed fuel?

 

Hmmmm they dont like 95 ron, it normally blows holes in the pistons and causes engine failure as they are mapped for 97+ ron, maybe one of the causes to your problems, this car NEEDS a minimum of 97 ron or the above can happen.

Tony

 

Wow, I did not know that. Glad i found out sooner rather than later...

Just taken the car out for a good long drive on my lunch, as with everything i've done, problem is better but not gone. It will hold at 70mph without pulling back, it's only noticable when going up hill now.

I'll fill up with 97RON tonight and see if that makes a difference. Thanks.

 

Reset your ecu again when you do

Tony

 

Yeah, as above. The ECU will re-learn. If the fuel octane is too low the the ECU will pull the timing back again.
Fill up with the highest octane available to you and even add an octane booster if necessary.

I take it when you did the reset, you got the 'all clear' code??

 

I did indeed get the all clear code after the reset. It's a big improvement.

I've been reading up about octane ratings and the more i read, the more it makes sense that cheaper, low octane fuel could be causing my problem. I'd not really considered it before, i must admit.

 

Excellent!

Read, read and read some more.
Very fickle beasts are these Scoobs mate. If they don't like it they will let you know.

 

I'm beginning to understand that! But so far, totally totally worth it. I never really 'got' scoobies until i was in one last year and thought, "Wow! Note to self, get one of these" and i'm so glad i did.

Thanks again for all the help and advice.

 

No worries. Keep us posted.

 

Yes. wife filled it with supermarket 95 and it exhibited the exact symptoms you described. On another occasion I was left with no opton but to fill with BP Ultimate. CEL illuminated for a few secs and the same symptoms arose and continued until I topped up with Tesco 99.

 

Just a quick update guys, a couple of weeks ago i replaced the MAF sensor and have been running it on V-Power. I did an ECU reset when replacing the MAF. Still have the same problem. Think i'm going to have to check all my hoses for leaks as i'm running out of ideas.... :'(