Mondial T Drain gas question

You can find octane booster in pretty much any auto parts store. How about pouring that in your tank instead of draining it?

 

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I am surprised your car would run so poorly on regular fuel, it is all about detonation and even then would normally only happen under a high load. You may have a batch of gas with water in it. There are dewatering additives, Redline makes a good one, to deal with that.

 

The coincidence is too great to be anything other than related to the gas fill. Drain the tank, period.
Octane and dewatering additives are just guesswork, right? How many bottles do you add of each? How do you get it to mix when you have trouble driving the car?
I have not looked at the Mondi tank, but the general way is to remove a gas line from the tank and either gravity drain or use the fuel pump to pump it all out.
I have never been able to get a suction tube past the anti theft flap, but perhaps you might be able to reach in there and rip it out forcibly.
Alternatively, it MIGHT BE that the Mondi fuel intake tube is connected to the fuel tank with a rubber tube (rather than a solid steel fuel inlet directly to the tank). If a rubber connection, then you could remove this tube and get a suction hose directly into the tank.

Save the fuel for cleaning greasy parts, or even for your mower...might work there..

 

You probably lost a bank of cylinders due to a malfunctioning slow ecu or thermal coupler.

 

It isn't guesswork. The instructions on the bottle tells you what octane increase you'll get when adding to 5 gallons, 10 gallons, etc. It will mix within a minute or two of driving and sloshing the fuel around the tank.

 

Under the impression that car was barely driveable, right? Liquids disperse in currents like the Mississippi entering the Gulf, not like aerosols and gaseous substances where there is rapid equilibrium of mixes.
Very interested in the final diagnosis. Please keep us updated.

 

You may be right about the fueling timing be coincidence, but no non-racing car runs that badly just because it is a few octane points down from optimal. Regular fuel actually burns better than premium, it is soley a detonation problem that octane solves for, at the expense of higher fuel volatility which actually has a better ignition property. The t engine compression ratio is I believe about 10.3 to 1, which is not that high. Unless there is a huge amount of carbon build up, raising the compression, it would still start and run, and but perhaps knock mre severely under load.

The only issue with draining gas is it is just dangerous, no matter how careful you are. You really don't want to do that if you don't need to. Always have a fire extinguisher nearby, garage door fully open for venting, etc.

The additive mixing ratios are straightforward. The additive will diffuse mix if you let it sit overnight, even if it is not sloshing around.

I would look for other issues as the priority, something else beyond bad gas is likely the problem. As noted, it sounds like you dropped a cylinder bank. Probably a distributor cap or a coil failure comes to mind.

 

Can you simply connect a hose off the schrader valve on the fuel rail and jump the fuel pump or pump relay? Run the hose into a container and run til nearly dry, then add proper fuel back. I also agree, it’s likely not solely gas problem.

 

Is it metallic clanking or a misfire or...?

I chased a misfire in my 348, and it was 30 year old spark plug wires. Ran fine, then like it was falling apart, then fine....then...

sjd