Tone Loc

iTrader: (1)

I used to run my WRX (93) on NUL and then switched to SUL. After reseting the ECU (after a couple of tanks) i didn't really notice much difference apart from it seemed to hesitate ever so slightly. I put it down to the fact it was due for a service.

For the past couple of fill ups i've been using Optimax, it went for a service and the ECU was reset as part of this. The car seemed much better but most of this i put down to the fact it had been serviced. Two days after the service i started her up (after being sat for about 5 hrs, so colled down) and it ran like a bag of ****e for about 5 mins. Its was jerky, no power, very hesitant etc. After the five mins or so it went as normal and hasn't done it since. Very strange .

I still think there is a slight hestitation there which wasn't apparent on NUL!?!?!?!

Im very confused, thougth this stuff was supposed to be the dogs bollocks??? Maybe cos i've read about hesitation problems its all in my mind (it is very slight).

Tony

[Edited by Tone Loc - 11/1/2001 2:06:42 PM]

RON

Hi all,
Not sure exactly what was going on so I though I'd ask if anyone else has noticed anything, I was travelling along after about 120 miles using Optimax, when the car started to sort of hesitate, could this be the ecu doing it's magic, I was only pottering along when it happened, it did it a few times but then stopped ( I hope).
has anyone else noticed this?
Ron
ps, my00 full decat, and filter,

bennetm

Put your foot down you *****!

MB

RON

Hi Mark, went to Castle Combe today three up in the car, had a great blast with a TVR, an old v8 tuscan I think,(he was in the mirror) several great high speed blips (on the track) after about ten miles he pulled off, falshed and waved, luvly jubly, there was no difference in acceleration right up to silly speeds!!!!
Why bother witha a TVR when you can have four seats!
Ron
ps gonna do ecu reset when I get a chance!

DMB

RON that would be where its shooting 2 foot of flame from that restrictive exhaust you have fitted

Mine hesitates when cold (but then it is a blue (grey??) piece of crap) but pulls nice and smoothly the rest of the time. i think marks on the right lines tho .

RON

DMB you cheeky get! My foot won't go down anymore!
Not had a chance to reset yet, might get around to it tomorrow.
Ron

JFB

Ron,

Your car aint used to pottering. Probably knackered the ECU by keeping the revs below 3000 for more than 5 mins!!!!!!!
Oh and with regard to your clicking clutch..........buy an automatic!!!!!!!!!!

Take care

Jerome

RON

But Jerome,
Auto's don't like mod's mate!!!!!!!!!
TTFN
Ron.

KF

I get some more hesitation with Optimax than Esso SUL. When pulling moderately hard from low revs sometimes it is like the Turbo can't be bothered, then you hit 5krpm and it's business as usual. Only happens with Optimax....
Ideas?
KF.

SCOBY

I,ve had my Terzo about 5 wks now, in the whole time i've had it i've been using NUL, on start up from cold it sounded perfect no unusual noises ( PERFECT), at slow speeds it was running lovely and smooth, no jerkyness no hesitation at all also on pulling away it was fine. I had the ECU reset a couple of weeks ago this didn't
seem to do much apart from bring the revs up a bit.

Couple of days ago I thought I would fill the tank up with SUL cos everyone says it makes it run a bit better, it was from SHELL but not the OPTIMAX fuel.

Everything I have described above has gone totally the other way now its starting to run very hesitant, noisy rattly engine from cold, basically im gutted and wish I had stuck to NUL, it sounds and drives like a bag of **** now.

nom

Interesting post date there.

I've been wondering if the hesitating that some cars do on Optimax & other's don't is 'cos the stuff's meant to clean the engine. If the engine's got deposits in it, they'll be flushed out (?) over the first few tanks, which will give this puttering stuff. If the engine's clean anyway (always used SUL or octane booster/whatever), there's no cleaning to do.
I've used nothing but Optimax for a while (it's the cheapest SUL round 'yer). To start with, we puttered about when cold with the Optimax, but now (15 tanks?) later, it's gone completely. Engine clean now? Dunno - just a guess!

bennetm

May just be a combination of things.. How many times do you get in and think, hmm, bit flat today... regardless of petrol. Ambient conditions can make a hell of a difference. I often think a lot of it is "great expectation" like fitting a new performance part and expecting a lot more from it.

Suppose the only way to tell is to revert back to normal fuel and see if that works... I use Optimax and thinks it's fine - not too much difference but the higher octane rating is just an added bonus to prevent chocolate piston syndrome - to a point!

MB

KF

Bennetm
I hate pseudoscience and am well aware of the placebo effect (re: Broquet threads). One thing is obvious to me. There has never been a stepwise delivery in power like there is with Optimax, and any expectations I had would be that the performance was better, not worse.
I have no science or proof, other than the obvious delay in power delivery.

So, I am willing to buy nom's suggestion - perhaps there is a cleaning effect. Only thing is my car is less then 18months old. I hope it isn't the case. Still - I am persevering, and it seems to be getting better.
KF.

bennetm

KF, apologies, I wasn't having a dig!

MB

KF

Sorry mate, my reply was a bit assertive, wasn't it
I totally agree with you - weather makes a huge difference. Scooby a cure for SAD? You betcha... I look forwards to cold wet days now
KF.