really bad running - im starting to wonder about this car...

[gcpeters]

on the way back from lemans had to fill up with 1/2 tank of french super market 98 ron stuff

started getting a bit juddery on the way back,

anyway got it down to half a tank and juddering, really lack of power etc so topped up with half a tank of optimax and everything seemed much much better, nearly perfect, a 100 percent improvement!

drove around till down to 3/4 of a tank and now the problem is back! really rough running, judderring, lack of power etc and then it goes smooth after about 2.5k etc but still feels "slow"

so today toppped up to max again with optimax, (about 20 litres) and its still running bad.. im planning to take it out at lunch, get it down to 3/4 again and top up, AGAIN!

is this the crappy french fuel? ive got to drive it 50 miles tonight!!! and then back another 100!

im really getting feed up with the cerb, the lows are getting more than highs!

any ideas anyone, im in swindon at the minute if anyone wants to take a look!

Grant

[cossiemetro]

lamba sensors ?? stick some injector cleaner through it might help

[Duke Thrust]

Have you checked plug leads, make sure everything pushed home properly and not trying to arc somewhere.

V8 or S6?

[headcase]

Possibly tank pressure vent thingy, if you take the filler cap off do you get a woosh?

[FUBAR]

gcpeters said:

on the way back from lemans had to fill up with 1/2 tank of french super market 98 ron stuff

started getting a bit juddery on the way back,

anyway got it down to half a tank and juddering, really lack of power etc so topped up with half a tank of optimax and everything seemed much much better, nearly perfect, a 100 percent improvement!

drove around till down to 3/4 of a tank and now the problem is back! really rough running, judderring, lack of power etc and then it goes smooth after about 2.5k etc but still feels "slow"

so today toppped up to max again with optimax, (about 20 litres) and its still running bad.. im planning to take it out at lunch, get it down to 3/4 again and top up, AGAIN!

is this the crappy french fuel? ive got to drive it 50 miles tonight!!! and then back another 100!

im really getting feed up with the cerb, the lows are getting more than highs!

any ideas anyone, im in swindon at the minute if anyone wants to take a look!

Grant

I have similar since putting damned Super U 98 ron in it at LM. Juddery around 2-2500rpm. Havent got any Optimax in it yet (tonight) but have put a tankful of French Total in, which has helped a little.

Its going into Austec tomorrow for a general check up so will ask them to plug it into the computer or whatever it is they do

[350matt]

If the fuel was very dirty then it may have clogged the filter ( In Passenger rear wheelarch )

Sposed to be changed every 20K or so anyway

Matt

[thegreengoblet]

headcase said:

Possibly tank pressure vent thingy, if you take the filler cap off do you get a woosh?

I'd agree... sounds like fuel starvation due to a blocked breather.
There have been some threads recently. Search the Cerb forum.

[headcase]

If i remember correctly the vent is via the charcoal filter which has a solenoid on it, its proberbly that thats not solenoiding (very technical explanation!)

[gcpeters]

well update so far

i had the pleasure of nursing the car from swindon to bath in my lunch break and then back here again in my super fast 1.9 diesel (non turbo) 306

the power....


anyway, tried the losening the cap thingy, no joy there but i have noticed it going wooosh sometimes when i take the cap off! Going to hook it up to the laptop over the weekend (first time, so hopefully will work) and check all the leads and all the plugs

it does feel like its getting fuel starvation, really down on power and chugging, no pops or bangs at all! and seemed to be a lot quieter!

Edited by gcpeters on Thursday 22 June 14:26

Edited by gcpeters on Thursday 22 June 14:31

[FUBAR]

gcpeters said:

anyway, tried the losening the cap thingy, no joy there but i have noticed it going wooosh sometimes when i take the cap off!

I was told by Austec, when Ive used 1/4 to 1/2 a tank of petrol, loosen the petrol cap a half turn to stop the pressure build up.

Never done it to my memory but seems good advice

[gazzab]

I found the cap loosen thing was worthwhile on my old Chimp. But not on eiher of my cerbs.
Not sure computer will show anything if prob is fuel filter etc related.

[gcpeters]

FUBAR said:

gcpeters said:

on the way back from lemans had to fill up with 1/2 tank of french super market 98 ron stuff

started getting a bit juddery on the way back,

anyway got it down to half a tank and juddering, really lack of power etc so topped up with half a tank of optimax and everything seemed much much better, nearly perfect, a 100 percent improvement!

drove around till down to 3/4 of a tank and now the problem is back! really rough running, judderring, lack of power etc and then it goes smooth after about 2.5k etc but still feels "slow"

so today toppped up to max again with optimax, (about 20 litres) and its still running bad.. im planning to take it out at lunch, get it down to 3/4 again and top up, AGAIN!

is this the crappy french fuel? ive got to drive it 50 miles tonight!!! and then back another 100!

im really getting feed up with the cerb, the lows are getting more than highs!

any ideas anyone, im in swindon at the minute if anyone wants to take a look!

Grant

I have similar since putting damned Super U 98 ron in it at LM. Juddery around 2-2500rpm. Havent got any Optimax in it yet (tonight) but have put a tankful of French Total in, which has helped a little.

Its going into Austec tomorrow for a general check up so will ask them to plug it into the computer or whatever it is they do

i put that super u crap in it as well, it wasnt at that little station round the corner from the main shop was it?????

[FUBAR]

gcpeters said:

i put that super u crap in it as well, it wasnt at that little station round the corner from the main shop was it?????

No it was one north of LM somewhere. Got of the A28 in a panic and stuck in the first petrol I found. I did also put in 2 tankfuls of probably the most expensive petrol in France (Total) at €1.42/L or some such .

Our esteemed leader Steve_T, being northern, managed to find an Intermarche with petrol at €1.29 IIRC. I wasnt going anywhere near that stuff. Badge snob me

[BLUETHUNDER]

It sounds like poteniometers,it may be just a coincidence that it started running rough when you put different fuel in.The pots really are crap,ive replaced three in a year,and they are the symptons you get as you have described.

[v8_oatz]

Amazing!

Having read this thread at work today I thought, blimey my tank produces a "whoosh" when I unscrew the cap and it runs pretty badly at low revs with too much of the pops and the bangs.

So I got home tonight, loosened off the cap and took it for a drive. What a difference! Unbelievable! The car is now much smoother at low revs, the pops and bangs are now occuring when I want them to (not all the bloody time).

So that's another job to add to the list - cure blocked breather/filter

[FUBAR]

v8_oatz said:

Amazing!

Having read this thread at work today I thought, blimey my tank produces a "whoosh" when I unscrew the cap and it runs pretty badly at low revs with too much of the pops and the bangs.

So I got home tonight, loosened off the cap and took it for a drive. What a difference! Unbelievable! The car is now much smoother at low revs, the pops and bangs are now occuring when I want them to (not all the bloody time).

So that's another job to add to the list - cure blocked breather/filter

You're most welcome

[headcase]

see, we even fix things you didnt even know was broke!