random rev limiter

[odl21]

In my 260 the rev limiter kicks in at random RPMs from about 3800 up to never. Seem to cut in earlier under load. makes overtaking pretty dangerous when the rev limiter suddenly kicks in at 4000rpm.

Anyone else's suffer from this?

[ksilver]

Could be a dirt maf. Give it a clean.

Get your questionnaire back to Tim and you'll get full access to the site where this sort of thing has been mentioned before

[Herman]

Or a dodgy fuel pump or orange clip

[MrDoodles]

As others have said, sounds more like fuel starvation!

I had something similar happen on one of my Mustangs and it ended up with the fuel pump being on it's last legs!

[LeRoiDeLaRue]

Looks like mine is fuel pump ... It will have cost me around £800 inc price of replacement pump, added to well over a grand spent by previous owners, trying to solve the same symptoms.

Nick at Austin has run diagnostics and the fuel pressure is (edit) very low at times.

It aint a rev limiter, it always does feel like fuel starvation. And yes, it IS dangerous, despite people saying it is great up to 3500 rpm and that you dont need to go over 3500. Rubbish. You need up to 5000 for max power sometimes to let the car drive the way it is intended, to make it into gaps safely when you would have every right to in normal driving. It used to drop off power with nowhere to go other than pulling over into the left hand lane via urgent indicators, as the car will slow down simply by coasting if the revs aint recoverable , and so without brake lights to warn people behind. And on single lane roads, overtaking could be hairier still, if you forget the potential for it to decide to just deny you the power. Makes for careful aforethought certainly, but at best irritating and at worst, potentially lethal.

Let's hope this cures the symptoms whatever the future holds for this otherwise delightful, raucously civilised, understated prince of the road, this automotive rare gem

[Julianp]

I suggest you ask Nick to disassemble and clean the pump thoroughly before replacing it. It's a fiddly job, but no problem for Nick! I had a similar experience on my car, when it would very occasionally hit a wall and not accelerate further. It took Nick a long drive one evening to experience the symptoms for himself, but it turned out to be dirt I the pump, probably from a bad lot of petrol. I saw the residue in the pump for myself and it cleared the problem completely.
Julian.

[LeRoiDeLaRue]

Thanks Julian. Nick said he had checked the pump during first visit in July and I can do no more than trust his judgement.
He acquired the new pump on ebay, which arrived at Austin today and I hope he can get it fitted and tested under same conditions as triggers symptoms before I set off on train at noon to collect tomorrow.

It seems then that there are at least three of us who have had this situation with our cars so I wonder how many others are out there with similar problems? Surely there must be a filtration fix to stop crap from poor petrol getting into the fuel system from the tank? Surely petrol should not be so contaminated in the UK as to lead to such issues anyway? One would think, at least

[Zt pony]

Don't be so sure ( surely petrol can't be etc... ) !

I know for a 100% that not all petrol stations are pumping out uncontaminated / "good"/ petrol !

Had a relation..worked in Big Supermarket chain Fuel Station..big town. They had water leak/ corrosion problems in their fuel storage tanks !!! Customers had complained/ questioned them about fuel problems with their cars..after fulling up. They, of course , denied it all.

I have read about various people's cars having problems ..due to petrol contamination etc...okay till they filled up at xyz station..then..!!! etc
They where often dismissed..now I am sure some where in fact true !

I always use Shell..Vpower/ Nitro plus ..BECAUSE..I know it's got alot of cleaning additives etc in it...which clean the engine and fuel system etc.
Plus Shell usually seem to have have newer stations ! None in supermarket situations..except Waitrose ..where the nitro's actually ..cheaper..than Shell Stations out on the open road

Of course, Ethanol in petrol ( 5% currently ) doesn't help the clean/ uncontaminated petrol situ..as the Ethanol content can cause corrosion in the fuel storage tanks !

Harry

Thanks Julian. Nick said he had checked the pump during first visit in July and I can do no more than trust his judgement.
He acquired the new pump on ebay, which arrived at Austin today and I hope he can get it fitted and tested under same conditions as triggers symptoms before I set off on train at noon to collect tomorrow.

It seems then that there are at least three of us who have had this situation with our cars so I wonder how many others are out there with similar problems? Surely there must be a filtration fix to stop crap from poor petrol getting into the fuel system from the tank? Surely petrol should not be so contaminated in the UK as to lead to such issues anyway? One would think, at least

[stevenw]

I believe you can get water in the fuel tank from condensation inside the tank due to changes in temperature particularly if the fuel level is low and the car parked up for long periods of time.

This may be able to cause rust inside the tank if it's not well rust proofed.

Also I would have thought that if the fuel nozzle has any bits of grit or dirt on the outside this could easily end up in your tank.

And as Harry says some petrol stations may have a small leak in their tank, which is expensive to fix so they'd rather not fix them if they don't have to.

If the leak is near the neck of the tank they might not be losing fuel but might get water and dirt seeping in.

[LeRoiDeLaRue]

Ah well, just had the confirmation car is good to go so its all aboard and off cross country

Might just start using Shell. The extra 3p or so per litre over Tesco may well save money in the long run. Thanks for the tips fellas