Rob Edwards

FWIW, Randy's episode convinced me to remove my FP gauge last week , so this is really a rhetorical question , but has anyone else noted discoloration of the glycerine in their gauge? The viscosity of the liquid doesn't seem to have changed but in light of Randy's gauge failure I wonder whether I need to pull the rubber plug and sniff for gas? I'm in no way suggesting that there's anything wrong with my gauge, I'm just curious.

Pic is from just before removal.

I will say that the gauge was very handy diagnostically for initial sharktuning, and when my fuel pump relay failed, and when I ran the damn thing out of gas. But having it on the rail did get draw some unwanted attention during the initial emission testing...

FredR

Roger,

Can't say I am too surprised to hear the source supplier's comment given the litigious society you chaps live in.

Similarly I have no doubts that the kit both yourself and our other 928 heroes supply are as good as can be sourced.

Given Randy's description I doubt the gauge would have experienced coil failure due to the fire so a simple pressure test should be able to determine whether the coil was breached-assuming Randy has not kicked the sh*t out of it already! If the coil is leaking it should be easy to tell whether it is from fire damage [consequence] or mechanical failure [causal].

Similarly, I suspect that once Randy saw what was going on he did not spend too much time studying what was happening as his pride and joy went up in smoke. I would think from Randy's description that the event lasted about 15 seconds start to finish?? About 5 seconds for the "what the f*^k was that" phase, 5 seconds to get to and open the bonnet, eyeball the problem etc and another 5 seconds to get the extinguisher operational and fire out. In a time of crisis our [human nature] recollection of events is not always quite what we think it is so it will be quite interesting to see if recollection and investigation tally.

Kind of ironic that the sum total of the $$ damage may probably be more down to the fire extingusher than the fire but I shudder to think of the consequences of not having had a fire extinguisher to hand!

The fuel rail scares the crap out of me -but perhaps I am too conservative. Having been involved in a gas plant explosion and recovery scenario many years ago and somewhat foolishly [at considerable risk to myself but too stupid to know it at the time] dragging a downed colleague to safety from underneath the resulting fire some 10m above us, I have spent a good chunck of my professional career trying to stop such things from happening. Pressurised hydrocarbon facilities are not too forgiving- big or small!

By the way I will be sending you an order shortly for new fuel hose fittings!

Best wishes and a speedy recovery for Randy!

Fred

SeanR

Mine has discolored also, kinda annoying but have not noticed any fuel smell or leaks. Am keeping an eye on it though.

Rob Edwards

Sean-

Good to know- when I took mine off there was no sign of any weep or wetness at all, and sniffing around the front of the gauge face gave no hint of gas smell, so I think the gauge is just fine. I would have no qualms about reinstalling it for diagnostic purposes.

77tony

Purchased the gauge kit from Roger just last week before 3rd Coast. No issues thus far. Fluid does look much clearer than Rob & Seans. Randy, hope your back on the road real soon. 77Tony

Tony

KNOCK ON WOOD. but i have really gotten A LOT of use from my Autometer gauge. Very handy trouble shooting..especially when i can view it on my cluster inside the car. It has a remote sender on the fuel rail. It is still drilled and tapped similar though. Been on...damn near 7 years maybe? Comforting to know now that Im back running "stock" fuel pressures and not 90 psi etc.

Still would like to know if it was the gauge or the tap/ fitting.

Rob Edwards

I want to be able to monitor fuel pressure for ST'ing purposes when the carputer thing happens, I was talking with Greg about plumbing an electric FP sender somewhere back under the fuel pump cover and running the wiring up and thru the FP harness grommet, then up to the center console. Will post up the implementation if/when it happens.

FredR

Rob,

I seem to remember reading in a profesional article that glycerine [as used in filled gauges] discolours at around 120F [50C]. If that is correct it would explain what you have experienced.

Glycerine is used to dampen the needle motion in vibrating service, thus if such is needed is it wise to keep the gauge on during use?

The temperature under the hood is probably around 70C to 80C I would guess [the air leaving the radiator is heated to about 90C] never mind the engine heat soak. That would thus explain the discoloration.

Most pressure gauges sit in an open air environment and the process media is static, so, even if the process is hot, the temperature in the Bourdon coil will not sit at elevated temps.

Finally, there are different methods used to put pressure gauges together. I would suggest that any gauge provided for this service should be specified such that it is capable of withstanding the heat soaked environment- say 100C?

Regards

Fred

ROG100

Lots asking for the cap nut and ball - $4.80 plus shipping.

Randy V

More detailed inspection after washing everything off shows that the root cause is clearly the fuel pressure gauge.

The paint blister on the hood is directly above the gauge.

A few pics show that the fire was very localized. My quick action resulted in pretty much the least damage possible in this situation.

That said, there is still quite a bit that needs to be done, not the least of which is repainting the hood and fenders.

Interior was covered in extinguisher dust.

928mac

Oh man Randy, I feel your pain. I have the fuel rail covers and maybe a few other things that I could send you.

The paint is the big ticket item.

SeanR

Guess now is the right time to say you should change those old fuel lines.

FredR

Randy,

The pics suggest that foam crap under the bonnet went off like a fire lighter! I presume that was the OEM stuff? I removed that gunge from my 928 and fitted the kit that Carl supplies. Same material I use for my sun shades. His website indicates he had a similar fire and the material saved the bonnet paint!

As to how much it protects from fire no real idea but for sure it must be better than that oil soaked soggy firelighter that Porsche fitted. Looks quite good as well but you have to be a bit careful aligning/fitting it [two man job-maybe even three] or it will look like a right dog's breakfast if you get it kinked halfway on once the contact adhesive bites.

Regards

Fred

SeanR

Randy, can you take the fuel rail cover off and post picture please? I want to know which adapter that is. It looks like there is sealing tape on it also. I'd really like to have this guage/adapter to put on my car and pressurize it up to see exactly where the leak is.

SteveG

Fred: What's a "live hose pipe"?