Wrong Petrol !!!

[The German Flower Pot]

As a few might know ive got a w124 twin turbo.

Since i got it its not really preformed or ran perfectly so ive changed this and that and it gets a bit better but its never been "MERC SMOOTH"

then tonigh im going through all the paper work for both my cars and inside my "turbo technics" brochure i find a sticker saying ...

FUEL
This vehicle is fitted with a catalyst

USE ONLY

SUPER UNLEADED FUEL
98 octane minimum

TURBO TECHNICS


now could this be the reason or probably nothing as its only had shell normal petrol in it

also on the metal turbo technics plate that is ment to be rivited onto the car it says

SPARK PLUG TYPE BCP6ES

does this mean i should not have just put normal NGK plugs in it?

any advise would be great

 

[television]

its OK to use an equivalent spark plug, the are hot plugs and cold ones both very different, they equiverent ones are fine if the same.

Most turbo cars need 98 ron fuel and you have 2 turbos

 

[The German Flower Pot]

cheers guvnoooooor

so running it on normal shell will make it lumpy and unresponsive at low end revs & pulling off?

 

[whitenemesis]

I would always go with the recommended plugs.

For fuel go for the best V-Max and possibly an octane additive.

You have a high performance engine treat it special

 

[The German Flower Pot]

IM NOT MAKING MYSELF CLEAR

the car does not run right

is it possible that that is down to not using the propper petrol?

 

[whitenemesis]

Umm, post #4?

How clear do you want it!

 

[The German Flower Pot]

i see you said use the other fuel and i will but you have not said if using the wrong fuel is making the car run lumpy and sluggish at low speeds & pull off

 

[whitenemesis]

Well, time will tell

 

[The German Flower Pot]

wise words

cheers

 

[keith100]

As a few might know ive got a w124 twin turbo.

Since i got it its not really preformed or ran perfectly so ive changed this and that and it gets a bit better but its never been "MERC SMOOTH"

then tonigh im going through all the paper work for both my cars and inside my "turbo technics" brochure i find a sticker saying ...

FUEL
This vehicle is fitted with a catalyst

USE ONLY

SUPER UNLEADED FUEL
98 octane minimum

TURBO TECHNICS


now could this be the reason or probably nothing as its only had shell normal petrol in it

also on the metal turbo technics plate that is ment to be rivited onto the car it says

SPARK PLUG TYPE BCP6ES

does this mean i should not have just put normal NGK plugs in it?

any advise would be great

Well you'll certainly have destroyed the cats! Dunno whether this means the car simply pollutes more , or that maybe also you now have greater/uneven back pressure in the system (plugged cat?), hence the uneven running.

HTH

 

[Ron Palfrey]

I think by normal he'll mean 95 octane unleaded. Not leaded petrol. He's probably been using "cheap" supermarket petrol too. My Corsa won't run properly on that, so it never goes in my Merc or the 206cc.
No doubt GFP will tell us in due course if the correct plugs and a few tankfuls of decent Super Unleaded improve matters.

 

[hmang]

can you still buy leaded petrol in cambs then .....cor!!!....wait till the greenies find out about that.

 

[panason1c]

...."I think by normal he'll mean 95 octane unleaded. Not leaded petrol"............



Even if you can find a staion that still supplies 'Leaded' fuel it wouldnt be possible to insert the much wider diameter nozzle into a narrow 'Unleaded' filler kneck, so therefore no fear of putting the wrong fuel in.

 

[Richard Moakes]

cheers guvnoooooor

so running it on normal shell will make it lumpy and unresponsive at low end revs & pulling off?

I used to run a Mazda RX-7 twin turbo, it certainly didn't like 95 RON fuel, I fed it 98 RON Shell V-Max and topped that off with bottles of octane booster.

I never noticed any real improvement in power, but I can definitely confirm the engine was smoother on a high octane mixture, additionally it was insurance against pre-ignition which is deadly for the rotary engine.

As Whitenemesis says, an engine like that needs the best fuel you can afford to use, turbo engines do seem to thrive on high octane fuel.

 

[stumpy]

And of course leaded or LRP is really really really expensive too.

 

[jibcl500]

Danny
the TT should run happy enough on regular unleaded and the plugs shouldnt make a difference either.

Its more likely the cars been sat and needs a good drive to get things cleaned up internally.

You say its had a service but whats been changed.

jib

 

[100%Bitch]

Take it out for a damn good thrashing, that's what I say.

 

[SLinKyjoe]

The car has been tuned to run on 98RON. Anything less will cause it to be a bit slow, or sluggish and it will not be running efficiently.

I would give turbo technics a ring to see what they recommend you do. Running it on 98RON may cure it, but it may also require a bit of fettling by tuning up again.

 

[Bolide]

I would give turbo technics a ring to see what they recommend you do. Running it on 98RON may cure it, but it may also require a bit of fettling by tuning up again.

I agree with phoning Turbo Technics

But how do you tune a car that has an ECU? It'll be trying to get the mixture right according to what the sensors tell it - so it'll measure the oxygen in the exhaust via the Lambda sensor, pull a value from a map according to the cps, revs, temp sensor, throttle position and MAF, and deliver fuel. The rest is up to how well the mixture burns

If it's running worse than it did when the engine was built then I'd say look for air leaks, fuel supply & injector problems, sensor problems, poor ignition and lack of compression. Timing and fuel delivery are determined by the AFM injection and the ECU map plus any TT alterations to the map

The quickest way of tracking down the problem might be to run it up on a rolling road. With the right setup you'll be able to measure spark advance, exhaust gas percentages, oil temperature, power and torque both on and off-load. That should nail down the fault pretty quickly. You'll also be able to see if the car is running lean at high revs - that's a sign of fuel starvation and an excellent way of melting pistons & killing an engine

If you can get graphs from TT to compare against your car the RR operator may well be able to pin down the problem quite quickly. I'd put my money on a fuel feed problem or poor spark

Every time I've run a car up on a rolling road I've concluded that, hour-for-hour, it's the best value automotive service you can buy

Nick Froome
www.w124.co.uk

 

[The German Flower Pot]

cheers people (except the cheeky bloke who said i probably use cheap supermarket petrol) its never had leaded in it

i use shell unleaded only in both cars

i bought the twin turbo in march 07, put £20 in it to drive it home from london (80 miles)

it was trailerd to northampton and back when it went to turbo technics

then put £20 in recently so ive only put £40 ish in it in 15 months and still has 1/3 of a tank in it

so shall i remove the petrol thats in it and put some optimax in it or just put optimax in ontop of the current fuel

i also put the odd tanks of optimax in the other coupe

cheap supermarket fuel in a merc ..... how very dare you sir !!!

is tesco 99 ron any good (id say not)