Searched a bit but did not find anything specific. Does anyone use a fuel system / fuel injector treatment in there SIII.

For example, STP, Wynns and many other companies sell "fuel system treatment" bottles that you dump in the tank (tanks)
and they claim to reduce gum and other ick in your injectors and fuel system.

Any thoughts on these solvents?

Thanks - Randy

 

I have NO scientific proof either way.

All mine have a had a bottle poured in whever I remember, and that is less now as age screams up too fast.

It was Redex back in the MK VII days and for many years after that.

The Infected fleet have a bottle about 3 - 4 times a year.

Brand, ????? whatever is on Super Special when I remember I need some stock.

The later stuff I am suoer careful with, O2 sensors etc, but the early stuff, pour it in, it'll burn.

BUT

I use our 98 RON in all of them, easier on that same memory. Claims from the Petro Guys is that stuff has cleaners, blah, blah, blah in it, who bloody knows.

I have NEVER had any injector cleaned professionally in all the Infected Jags I have owned.
Maybe its the fuel we have (NO Ethanol to speak of), or just plain good luck.

ALSO

None of mine ever sat around, on the go 24/7, so the fuel never had time to go "off" and gum stuff up.
We dont have this "Winter Storage" thing, so we be blessed I suppose.

 

If you are using a premium (91 octane) first tier gasoline the fuel already has cleaning additives in it. But it a good idea to run some Chevron Techroline through the fuel system once a year or so to clean up the changeover and fuel return valves as well as the injectors. Far better than the snake oil brands like STP...even better, BG44K.
Current Jaguars use a direct injection system in their engines and have far more stringent requirements for fuel and oil. The Series 111 cars are just " the most modern antique vehicles"....hmmmm...somebody has already said that.

 

Still will look into BK44...but this was a sign from on high..two tanks...BOGO score 😊

 

I believe they are all Snake Oil.
Since owning my 1984 I have never added anything to the tanks but gasoline. Never had any "injector treatment" done either

My nephew, who is a Honda / Acura "Star" technician with multiple awards, says that injectors by their very nature, don't get clogged, but he is happy to unclog them for $350.00 per job to satisfy the customer because the customer is always right and he needs the money.
​​​​

 

Ha ha Jose

I tend to agree... But for $10 I will sleep better knowing Chevron made a profit...and full disclosure...I own their stock!!

 

There can be multiple reasons for why an injector spray pattern is interrupted (what we would call blocked) and this certainly can and does affect the performance of injected cars. The most common cause in Series III cars is rust caused by moisture in fuel (either from the effects of hot delivery to the storage tanks at the retail site and then cooling in the ground) or from a car that is siitting for extended periods. I once had a lab technician friend analyse several of the most common "injector cleaners" on the market here in Australia. I also asked, "is it something I can easily reproduce from commonly available products?". But before the answer, comes the disclaimer... just because I have used the following, does not mean it is safe or wise for you to do the same... anyway, the short answer is that the mixture was simply 90% hydrocarbon and about 10% lubricant. So on my friend's recommendation, I mixed general purpose paint thinners eg: acetone (90%) with 10% automatic transmission fluid and added one litre of that mixture to a tank full of fresh fuel on customer cars that were exhibiting likely injector issues (after testing on several of my own, naturally). Am I suggesting you do this on your car... no. It should certainly never be done on a more modern vehicle with plastic petrol tanks/fuel lines or on a vehicle with a catylitic converter. Depending on your local emissions laws, it may also be illegal in your territory. But it has yielded useful improvements over the last 25 years and when you work out the costings for a twenty litre drum of thinners, subtract one litre... add one litre of Dexron III ATF, shake vigorously (just kidding)... it is a VERY economical alternative to spending between $10 and $20 on a single bottle of commercial injector cleaner. Just my own personal experience...

 

In the ancient motorcycle community, Seafoam is the stuff you would want to have.....
Here in Europe readily UNavaible though.
I use Fuel System Cleaner and Engine Flush from Forté (which most likely again is UNavailable in the US).

I bet it's the same stuff though....most treatments are nafta based....

 

Naptha ??? The only one I have any degree of confidence in is Techron. Ruan atank of theor more expensive fuel at times.or a bottle from the parts store of Techron.

 

M firsthand experience would say definitely-maybe. At least on a more modern car. I had a 2005 S-Type Supercharged which was running way to lean per the fuel trims shown by OBDII. I watched the live data fuel trims improve while I ran tank after tank of injector cleaner. After about 5 bottles my fuel trims were back within range and my OBDII drive cycle completed allowing me to finish inspection. Not sure if a vintage XJ SIII would be the same.