Down on power and very lumpy

[Cupman29]

Went to a rolling road session today but never actually managed to get the car on the rollers.

I had to drive about 40 miles and the car was running fine. On the way I filled up with £20 of tesco 99 as I was sitting about 1/4 tank. Parked up when I got there and waited my turn. It took about an hour or so before it was my go and when I started the car again it sounded like a bag of sh*te. Went for a quick drive to see if it would get better which it did for a moment or two then as I went to go onto the rollers it started again so I decided not to bother.

Sounds like it is running on 3 cylinders. I zero'd my mpg for the way home and I still got about 38mpg doing about 50mph all the way. I was getting about 44mpg on the way there sitting at 70mph.

I am going to check compression and currently have a Decat on which will be swapped over to the cat tomorrow.

Any ideas what it could be, Lambda, bad fuel??

 

[Nick172Cup]

Does it come and go running on 3 cylinders? If so could possibly an injector.

Coincidently Ollie off here recently put some tesco 99 fuel in his cup and after changing a few things it was an injector that failed.

 

[Cupman29]

Did come and go at first then just came and got worse as I drove home.

I use tesco 99 on all my cars and have never had any bother even on my Impreza and the wife's Cupra. I have heard of dodgy fuel batches so might be a cause. Thought it might be cat related or Decat related as it was as the engine warning light stays on all the time with the Decat but today it started flashing. I've not got a code reader or rstuner to check it but do you know if ollie's light was flashing when his injector packed up?

Cheers for the suggestions though!

 

[Nick172Cup]

Nah he didn't have any warning lights out with the injector problem, best bet is getting it plugged into an Rstuner/CLIP etc and should tell you what's going on.

Nick

 

[DannyR]

100% injector!

Pull off each injector plug and determine which one

 

[Cupman29]

I'll take a look. Any cause you can think of?

Car is on 70k but this year is all track day miles.

I'll take a look and see whats what. Thanks again guys!

 

[DannyR]

Cold weather, this time of year they seem to go.

 

[Cupman29]

Removed all the injectors and gave them a flush through with injector cleaner. Injectors 1, 2 and 4 were fine and sprayed well but when no 3 was getting cleaned it started to sizzle slightly and then this happened:

Looks like I need a new injector then. When putting some voltage to open the coil in each injector, 3 sounded the same but injector no. 3 seemed to warm up a lot more than the others so looks to me that it was the solenoid of the injector rather than just being blocked with carbon or whatever that caused the issue.

Thanks again for the advice!

 

[DannyR]

No problem mine was third from the left too!

 

[Cupman29]

Funny that. whats the significance of no.3 injector.

In subaru's it is no.3 cylinder that has most issues due to it being closest to the turbo but I wonder if there is something on the f4r's too or maybe it's just you and I. :rasp:

 

[Greeny.]

I have a feeling it was the same on mine last year as well :S

 

[DannyR]

I think yours was Dan as I thought of you too

 

[Greeny.]

I think yours was Dan as I thought of you too

xoxo

 

[Cupman29]

3 out of 3 so far and a love story for good measure.

 

[Greeny.]

lol

 

[Cupman29]

The wife was asking if we could watch Brokeback mountain tonight, told her I'd just seen it on this thread. lol

 

[Greeny.]

oh gawd