Have i killed it? :(

Just got back from a weekend away at Donny and Alton towers. All the way up there and around Donny the car was fine apart from the odd boost spike (peak 1.26ish) . Left Donny for Alton Towers and filled up with some Tesco super unleaded (branded as 97 ron), the car normall runs on SUL (99RON).

The car seemed fine on the way to Alton, wasnt really giving it any beans to tell tbh, although in the back of my head thinking about it i dont think it was a quick as it normally was.

So anyway, on the way back to Essex i thought id get some more readings of my AFR's as i havent managed to collect many, previosly i was hitting low 12's to mid 11's.

Well, upto 4k the car seemd fine and still does. After 4k the car seems to hesitate and judder This is intermitant through the rev range all the way past 4k. (IE 4.7k - 5.2k = problem, 5.2=5.5 = fine, 5.5 - 5.8 = problem, 5.8-6.2 = fine........you hopefully get the idea) I tried this a handful of times and it still did the same thing. I arived home and was fairly low on fuel anyway so thought id try putting my old faithful fuel in. Stuck £30 of Tescos 99'er in and drove about for 20 minuites or so under 4k. This was fine but after the 4k mark i was was still experianceing the hesitant acceleration and the juddering

I have also noticed that boost levels are only reacing around 1.15 and my AFR's seem to be mid 12's to mid 13's.

For reference im running

Double decat

Cat back exhaust

FCD

Greddy profec B spec II

IK24 plugs

Apexi Induction

Any ideas fellas? I havent a clue but then im crap at this sort of thing

Checked your plugs?

Ney, tis dark and cold and im scared of the dark

But seriosly no, they were replaced perhaps 5k ago thou. HKS 60k jobbies that cost me a few quidd short of a ton. Without doubting you, why would the plugs effect only after 4k? *gets pen and paper ready to lean something*

That sounds like what mine was doing, changed the plugs and its better but I'm still getting a slight bump bump sometimes.

Does it do it on full throttle? mine was fine say 70 - 80% throttle but hesitated and pulled back on full pedal mash.

It does seems more apparent at WOT.......not much thou.

Ney, tis dark and cold and im scared of the dark

 

But seriosly no, they were replaced perhaps 5k ago thou. HKS 60k jobbies that cost me a few quidd short of a ton. Without doubting you, why would the plugs effect only after 4k? *gets pen and paper ready to lean something*

If the plugs are worn then the gap gets bigger and the boost from No2 blows out the spark. Shows more on like 4th gear onwards.

Jake suggested to me to try them first as the NGKs only cost about 14quid, I've ordered coil packs anyway due to the state of mine but was ready to cancel if the plugs were all that was wrong.

my car did this after I went from Optimax to normal unleaded. I was told it was because ECU learns what fuel you run ie the 99ron and at high boost and adjusts accordingly. Then you put poorer quality fuel in and try and drive it the same the ECU is not happy at all.

I was told to put 99ron back in it which you have and reset the ECU. Worked fine on mine. If not go the plugs route... HTH

Funny you should say that, 1st (auto) the problem is not as apparent as say 2nd. Although a larger gap after 5k?

my car did this after I went from Optimax to normal unleaded. I was told it was because ECU learns what fuel you run ie the 99ron and at high boost and adjusts accordingly. Then you put poorer quality fuel in and try and drive it the same the ECU is not happy at all.

 

I was told to put 99ron back in it which you have and reset the ECU. Worked fine on mine. If not go the plugs route... HTH

Ok cheers Darren, ill look into that

I had a similar sounding problem Daman. Mine turned out to be the o2 sensor.

^ Thats what happens when you put in Tesco unleaded

I had a similar sounding problem Daman. Mine turned out to be the o2 sensor.

Again, its a new one

Im gonna go with the shit fuel theory, reset the ECU and go for a spin. Ill post my results

Hi damian, i had same prob reset the ecu and sorted everything out!!

But then 2 weeks later same prob:( , reset ecu and fine again:)

this did happen one more! time but since then no probs at all been fine for 6 months now!

Now im not to sure what caused this:search: but all seems ok now(very strange)

Hope this works for you!

Alot of people experience this if their plugs/coil packs are failing, but i dont see how reseting the ecu would help that prob:search:

Best to touch wood and put it down to dirty fuel (we hope)

See you around..

Chris

Hi damian, i had same prob reset the ecu and sorted everything out!!

But then 2 weeks later same prob:( , reset ecu and fine again:)

this did happen one more! time but since then no probs at all been fine for 6 months now!

Now im not to sure what caused this:search: but all seems ok now(very strange)

Hope this works for you!

 

Alot of people experience this if their plugs/coil packs are failing, but i dont see how reseting the ecu would help that prob:search:

 

Best to touch wood and put it down to dirty fuel (we hope)

 

See you around..

Chris

Did you check fault codes?

Yes i did, each time by connecting a bit of wire to the diag box (read on here what to do)

And it showed no codes!!

as i said it really puzzled me and still does? maybe one of my coilpacks is breaking down?? but then why would a ecu reset cure the prob?

had new toyota plugs in it when it happened, and their still the same plugs!

now im feeling really confused!!

if your 2nd blowers kicking in around 5k then its the prespool which isnt happening isnt it?

EBGV or somthing

but the problem over 5.8 k could be misfire, check your plugs

How did you get on Daman?

(I'm still betting on plugs though!)

if your 2nd blowers kicking in around 5k then its the prespool which isnt happening isnt it?

 

EBGV or somthing

 

but the problem over 5.8 k could be misfire, check your plugs

Prespool seems fine Ric

Adi.........just about to go pulling fuses now.........

 

Adi.........just about to go pulling fuses now.........

Didn't work

time to get the plugs swapped out

Will give it a go tomorrow night after work

As suggested, swap the plugs out for some cheapie NGK's, while you're there pay very careful attention to the white coil pack connectors. If they are brittle or not 100% perfect then swap them out.

If its running okay off boost then its not the O2 sensor.

I have some denso ik24's with only 10k on them, im going to pop them back in as i never had any issues with them

Sounds like the plugs to me. Had a similar issue in my GTR using Denso's, I would go with NGK's from now on.

As suggested, swap the plugs out for some cheapie NGK's, while you're there pay very careful attention to the white coil pack connectors. If they are brittle or not 100% perfect then swap them out.

 

If its running okay off boost then its not the O2 sensor.

Well one of them fell out of the conector, i tried putting it back in and it snapped in half rather easily. Ive popped it back on, without the white clip, and it found its key ok, is this going to be ok or should i replace it? If so, just the white bit or the entire plug?

Annoyingly the so called HKS plugs that were put in for £100 turnt out to be NGK's

http://img66.imageshack.us/img66/4129/img00861sizesq6.jpg

http://img110.imageshack.us/img110/5484/img00881sizesa7.jpg

Anyways, they look good to me. Just want to get the ok on the coil pack connector and ill go and try it out