Possible Fuel Contamination?

[Jphdg]

I took a drive out to Lethbridge Victoria today, about one hour and thirty minutes drive from Melbourne. Car ran really well all the way out there. Started with 3/4 tank of PB Ultimate fuel from Melbourne and on our way back to Melbourne stopped at the big BP's opposite each other on the Geelong Road for a quick drink. I decided to top up the fuel whilst there with Ultimate to save me doing it later this week when running around.

About five minutes after leaving the servo the car all of a sudden started to feel sluggish on cruise and felt like it was hesitating and vibrating more than missing. Backed off and applied the gas and it picked up normally.
Returned to cruise and the same thing happened again. It happened on light throttle / light loads and when slowly pressing down on the accelerator it would suddenly jolt back to life and start to pick up speed smoothly.

I am sus it is bad fuel due to the fact it suddenly started to happen not long after leaving the servo, but thought I would get some opinions as well on this one.

I am actually tipping it may be contaminated with water, as to add to the suspicion on fuel, I noticed a funny exhaust odor when I pulled over and it reminded me of the exact same smell from a four stroke dirt bike I had which I later found had mildly water contaminated fuel.

No white tips. They look normal and no signs of anything funny there.

Interestingly at idle, the car feels normal, not rough and anything other than very light throttle, the car behaves normal so not really sure about an 02 issue.

I had a check under the hood tonight and all tubes etc seemed fine. No vacuum leaks I could spot anywhere so doubt that is the issue.

Could still be 02's but would have suspected those more so if it was running rough at idle and have not noticed the problem occur beforehand.

I am going to get a logger on it anyway in the next few days and see how the 02's and other sensors are acting, but wondered if anyone else has experienced these symptoms and could shed some more light here.

Also important to note, there is no engine light coming on and everything else seems to be as per normal. Engine temp etc remained normal all day.

Also, I am thinking of trying an additive that is aimed at sorting out any mild water contamination issues in the fuel to see if that fixes the current symptoms.

If anyone has any other thoughts or suggestions, please feel welcome to comment.

I will be sure to post my findings anyway soon.


Mods? Yep a few... Intercooled PWR blower, larger injectors, GTS cam shaft, Pace Maker extractors and xforce duel exhaust system to name a few of them.

Cheers
John.

[Peter B - CV8]

Metholated spirits will allow the water to "blend" with the petrol. Add 1 litre to a full tank (or less - depending on how full you tank is), and run it down to the very last couple of litres of fuel. Give the motor a workout as you use up the blended fuel - nothing silly like redlining, just run it up a bit - so you get the injectors fully opening.
Might not be a bad idea to then change your fuel filter - before filling the tank back up.

[Jphdg]

Thanks Peter-B

I am about to go run a logger on it today before I do anything else and make sure its not 02's or other sensor issues.
I probably will then give the bottle of metho a shot and see if it comes good if the above does not show any obvious problems.

It is due for a service fairly soon anyway, so will ensure the filter gets replaced then as well.

Will see what results from the logger data.

Cheers Peter

[Peter B - CV8]

Good luck with it..... You might want to also check that an ignition lead hasn't come loose. One of mine did - whilst pulling out of the servo from a fill up. Luckily I checked under the bonnet & found the problem (I was about to chuck a wobbly at the servo owner for dodgy fuel):vpo:

[macca33]

Very interesting. A couple of years back, I filled up with BP Ultimate at a servo in Bendigo and the exact same thing occurred - felt like plug lead was off - car wouldn;t rev past 4000rpm, etc. In the end, I changed the fuel pump and when the tank was pulled and emptied, a lot of rubbish and gunk - rusty coloured - came out. Whether the fuel was contaminated, or it was mere coincidence cannot be established, but it certainly gets one thinking.

Good luck with it.

cheers

[Wonky]

There is a BP station in Chev's area that experience of his customers shows is worth avoiding as for some reason their Ultimate seems to be crap. Cars that have filled there consistently read around 20rwkw lower than previously on Chev's dyno and feel noticeably sluggish, though misfiring etc is apparently rare.

[Jphdg]

I found out something interesting today during my tests, I ran the car for a while and warmed it up. I was unable to read my 02's and many other PIDS and I think I may have a slightly different OS in the car due to the blower etc.
I will need to investigate that further another time to make sure I am using the right setup for logging.

Anyway so what I did after this was go for a drive and then switched between open loop and closed via laptop control.

When the car is warm it will run in closed loop (uses 02's) and open loop relies on fuel tables set by the tuner, ignoring 02 signals.

In open loop there was no issues at all and the car ran fine. It had no flat spot anywhere and had good power everywhere.
Then switched back to closed loop while cruising and a few seconds later the problem came back. I think that probably rules out plugs, leads etc anyway and perhaps even the fuel itself now. The splash of Metho has not helped.

Looks like it just might be the 02's after all from the open loop test above, but will run the tank down a little more and then fill up at my trusty servo here anyway and see if it makes any difference at all. Still seems odd the problem started moments after leaving the servo yesterday though.

Going by this, would people lean towards the 02's been cooked?
I would probably know for sure if I could see them in the logger, but I am almost convinced by the open loop test today, these likely are the culprit.

[Chappy]

Very interesting. A couple of years back, I filled up with BP Ultimate at a servo in Bendigo and the exact same thing occurred - felt like plug lead was off - car wouldn;t rev past 4000rpm, etc. In the end, I changed the fuel pump and when the tank was pulled and emptied, a lot of rubbish and gunk - rusty coloured - came out. Whether the fuel was contaminated, or it was mere coincidence cannot be established, but it certainly gets one thinking.

Good luck with it.

cheers

Funny you should say that Macca, I filled up at the BP servo in Ayr and got a tank full of crap to.

Ended up costing BP $1400 to fix the problem.
New Pump
New Fuel Reg.
Tank removed drained and treated with chemical and a small video camera was use to check the inside.
New Injectors
Retune by my tuner
New fuel filters
All the fuel lines flushed

It took a couple of weeks to sort the problem out but all ended well my way.

Moral of the story NEVER fill your car if a Tanker is filling up tanks or has been in the last hour or so.
If I am not sure I ask how long ago was the tanker here topping up your tanks.

ok cheers
Ken.

[sld86]

Funny you should say that Macca, I filled up at the BP servo in Ayr and got a tank full of crap to.

Ended up costing BP $1400 to fix the problem.
New Pump
New Fuel Reg.
Tank removed drained and treated with chemical and a small video camera was use to check the inside.
New Injectors
Retune by my tuner
New fuel filters
All the fuel lines flushed

It took a couple of weeks to sort the problem out but all ended well my way.

Moral of the story NEVER fill your car if a Tanker is filling up tanks or has been in the last hour or so.
If I am not sure I ask how long ago was the tanker here topping up your tanks.

ok cheers
Ken.


Interesting you say that as i just made a complaint to bp head office about shit fuel at a certain servo, filled up there last night and has been pinging its head off since about 50k's after. Interested to see what the outcome is, wonder if i can get new pistons outta them lol .as this is the 3rd time ive had bad fuel from a bp so there probably not all that healthy lookin

[Jphdg]

Just a small update on this,

Forget trying to get under the car in the front yard! :(

I can reach the 02's easy enough but can't get my fat hands up between the transmission and car body to reach the damn plugs. Also there is no slack to pull the plugs down enough to reach them, so a different approach is needed.

I know someone with a hoist, so next week will see if i can drop a few beers off for them and I can get under there with a good light on the hoist and swap the 02's over a little easier. All up, should not really take more than 10 minutes to do it.

Picked up a set of Bosch 02's from Repco today as that is what seems to be the go from other threads I have read about 02 sensors and the GenIII.

Got the pair for $181.90 so $90.45 each. Could have got them a bit cheaper hunting around, but could not be stuffed and some people spent up to $120 for just one, so went ahead and bought them.

Anyway, when I have em in, will let you guys know how it all goes.
The tests yesterday to my surprise brought me to the conclusion I probably am on the money with the 02's and the fuel might be fine. The new set will do no harm anyhow and was good enough reason for me to get some newies.

If not, will be getting a sample of the fuel examined whilst looking for anything else this could be.


Till then, have a happy new year.

[Chappy]

Interesting you say that as i just made a complaint to bp head office about shit fuel at a certain servo, filled up there last night and has been pinging its head off since about 50k's after. Interested to see what the outcome is, wonder if i can get new pistons outta them lol .as this is the 3rd time ive had bad fuel from a bp so there probably not all that healthy lookin

I often wonder weather the so call 98 ron fuel is 98ron I have noticed that some times it will make my car ping a little and other times its ok.

It would be good to be able to test fuel some how, to be sure of what your are paying for is what you are getting.

oh well

[Wonky]

From different servos Chappy?

[SS Enforcer]

I often wonder weather the so call 98 ron fuel is 98ron I have noticed that some times it will make my car ping a little and other times its ok.

It would be good to be able to test fuel some how, to be sure of what your are paying for is what you are getting.

oh well

It is at least minimum spec when it leaves the refinery All Fuel is tested to make sure the batch is ok before it's released. The 98 fuel is very closely monitored by all the majors for inconsistancies. I remember a batch of Optimax that came out at 102 ron !!! It isn't uncommon for those fuels to be a point or so higher than 98.

I have had E10 samples taken out of my tanker before leaving the terminal to make sure it is on spec as well this is done quite regularly.

cheers

[macca33]

It is at least minimum spec when it leaves the refinery All Fuel is tested to make sure the batch is ok before it's released. The 98 fuel is very closely monitored by all the majors for inconsistancies. I remember a batch of Optimax that came out at 102 ron !!! It isn't uncommon for those fuels to be a point or so higher than 98.

I have had E10 samples taken out of my tanker before leaving the terminal to make sure it is on spec as well this is done quite regularly.

cheers
That, too, is interesting. If the fuel is tested at 98RON at a minimum, what if, by some chance, you filled and got your car tuned on fuel that was actually tested at, say 101RON?? If you cannot get a batch that is at that rating again, you may suffer detonation / KR, as the timing tables may be out. It makes for an interesting thought, I reckon.

A few weeks back and after a few fills at different sites, I was suffering a mild ping between 4000-6000rpm. I ended up taking 0.5 deg out of the relevant timing table cells and it has been fine ever since.

The difference between ping / KR and it running perfectly can come down to slight changes, so if the fuel is inconsistent, perhaps that is where people are having issues.

cheers

[Alister]

Yep, government testers come out and test octane ratings too.

Last time we got tested, V-Power was 99.4ROn.

[SS Enforcer]

That, too, is interesting. If the fuel is tested at 98RON at a minimum, what if, by some chance, you filled and got your car tuned on fuel that was actually tested at, say 101RON?? If you cannot get a batch that is at that rating again, you may suffer detonation / KR, as the timing tables may be out. It makes for an interesting thought, I reckon.

SNIP

The difference between ping / KR and it running perfectly can come down to slight changes, so if the fuel is inconsistent, perhaps that is where people are having issues.

cheers

Probably a good idea not to have the tune on the edge like I have done. A batch at 100 ron or over would be rare but there never under 98. The only possibility that it is under that is when a contamination occurs after despatch via a petrol mix whilst unloading or funny buggers by the proprietors.
Both of those instances are very rare considering the tens of millions of litres of fuel delivered each week in Australia.

With E10 however it is a bit different in that the ethanol content is set at a max of 10%. Legislation forbids it to be over that amount and it could be E5 and still be a legal product or even E0 which has happened at some sites when there was an ethanol shortage. If you tuned your car on E10 and ran std ulp you would also have an issue as e10 is 95 ron and you will need to richen it up a bit from 98 as stoich for E10 is 14.2 I think.

I chuck 30 or so litres of E10 in my car quite regularly to keep any water out of the fuel system it's the same as chucking 3 litres of metho in it and cheaper.:) That usually pushes my AFR's up by about .3 of an AFR point.

cheers

[Jphdg]

Well, I can finally say 02's for sure now, as the problem has been rectified. I swapped out the old 02's today and put in some Bosch ones as many seem to go with.

I bought these after getting a bit sus on the old ones after my diagnostics results. Car was running fine in open mode, but not in closed at that point.

Problem now solved. Car runs very nicely again in closed loop on new 02's and no more flat spots or hesitation anywhere. Seems to be running better all around. So turned out 'not' to be the fuel after all, but good old typical 02's issue.

Happy man once again and a few more days of annual leave left to go out and enjoy it now!

Nice to be able to work through these issues yourself and get it back on the road again.

Cause of it? Maybe, maybe not - the right hand bank cat had taken a fairly nasty hit underneath and had seen better days IMO.
Took it down to the exhaust shop and got some hi-flow cats put on it to be on the safe side, as the internals looked questionable where the cat had taken the hit. Better safe than sorry i guess as restrictions there are a no no for blown applications :nyuk:

Will see how long these 02's last.

[Wonky]

Nice to see an "easy" fix apply! :goodjob: