philesk

A few weeks ago, on a PCA tour to Paso Robles to visit the James Dean Memorial, my 1982 US suddenly stalled and died after some spirited twisty road driving just as I was turning into the driveway of a winery.

1. Loss of power, like ran out of gas and tried a few restarts. Sputter, die.

2. Outside temp was 105F.

3. Car has all-aluminum DEVEK radiator, newer fan clutch, low-temp thermostat.

4. Temp gauge was not high. Normally, this car runs at or just below the second from bottom white line.

I lifted the hood and was pondering my options while I sent my wife onto the winery with another member. After about 20-30 minutes, we were going to push the car back onto the road to make it easier for a tow truck to ****** the car. Just for kicks I tried starting and it started fine. I drove up to the winery and did some tasting and let the car cool with the hood up.

Later, as outside temps came down, I was able to continue the tour to the coast and cooler weather. It hasn't exhibited this symptom since.

A mechanic I respect discounts the possibility of vapor lock on a fuel injected 1982 US928. He cites fuel pump, relays, and computer brains as possible culprits. However, my AC blows cold and the in-cabin temps were not over 80F, so I tend to doubt a heat problem with fuse or brain.

I have owned this car for over 15 years and only once before had a similar problem - hot day, car died just as I pulled into the parking lot on top of Mt. Rushmore. After cooling, every thing was fine - for 15 years.

Any ideas, suggestions would be most welcome.

Landseer

Here are a few

Vac leak / distributor adv.
Hidden corrosion in ground strap or engine electronics ground.
Degrading green wire.
Breaking diaphram in damper or regulator.
Leaking injector.
Wires behind panel barely melted into a short where they cross.
Boot crack/leak.

When speculating, don't underestimate the ability for a hypothetical part flaw to be intermittent vs constant, especially as the symptoms emerge.
That's been my takeaway so far, at least, in bringing various 928s back into running condition.

nc_growler

Interesting. On the day I picked my car (Labor Day Weekend 2010) and drove it back from NY to NC, I "ran out of gas" on I-87 after burning just over a half-tank.

I called a wrecker service to bring me gas (waiting 90 minutes on the side of the road in 95+ degree heat ). We poured in 2 gallons, she fired up, drove to a gas station and put in 10 gallons.

I haven't taken it under half a tank again, but I suspect I could with impunity after reading your email...

Landseer

That's interesting and reminds me of fuel tank collapse.
The pump can literally suck the tank down if the vent is messed up.

bronto

There is a long thread about vapor lock here, and yes it does happen. If I recall correctly, there is a place near the exhaust manifold where the fuel can boil under the right circumstances. The solution is to wrap some heat shielding around the fuel lines. I haven't done that to mine yet.

I have gotten vapor lock at 85 degrees, 5000 feet elevation (Shaver Lake) and 80 degrees, 10,000 ft (Tioga pass). Symptoms from Tioga persisted until I got out of the park at Oakhurst (102 degrees, 2000 feet).

Mrmerlin

A few other things to consider the fuel quantiy,
if your running less than a quarter tank the fuel will heat up a lot faster.
This means it is closer to its boiling point. Yes the AC system is made to cool the fuel but once the total quantity drops , the cooler cant keep up
If you ever have a fuel starvation issue go and check the tank immediately see if it looks like it has collapsed, a vacuum to the tank and hot fuel will make the tank more pliable
Make sure to replace the fuel pump fuse if your car dies just because... This has gotten a few owners that have an otherwise drivable car

all4woody

I had a similar problem with the tank vent line being crimped or clogged, it would run fine until the pump couldn't suck any more fuel, then it would die. It eventually collapsed the fuel tank.

philesk

Green wire is new. BTDT.
CD box replaced.
Injector connectors replaced.

philesk

I had both fuel pumps fail on my 90Gt. DEVEK replaced both pumps and one week later - failed again. This time it was just the fuse. No problems since. My problem is not the fuse. That was the first thing I checked. Took it out and turned it around. Car still didn't start until I had waited a while.

philesk

I read through that thread which seemed to apply mainly to early K-Jet cars. Mine is an L-Jet. I will probably try to locate that fuel line near exhaust and wrap it.
In the interim, I will try not to let the fuel level go below 50%.

philesk

When the fuel tank collapses, does it return to proper shape when the car cools down and tank is filled? My tank will take the full amount. I think it holds nearly 22G.

philesk

This has only happened twice in 15 years. Once at high altitude and recently at high temperature. I can't get a repeat, and most mechanics cannot deal with an occasional problem - they can fix evident and repeatable problems. I do very little of my own work, so speculation costs me $135/hour.

Mike LaBranche

Could have just been a stuck fuel relay. Had a 78 that would do that every so often, jump the relay next time and make sure you have a fuel pump. That's not running, other essentials down the line don't run.

philesk

Thanks, Mike. I'll get and carry an extra FI relay. I think I'll probably wrap the feul line if I can find where it gets close to the exhaust. Anyone have a photo?

Landseer

I left mine sit for a week in the sun afterwards. Had about 6 gallons or so of gas. Yes, it returned to shape and fuel gage began working again.

Symptom is air rushing into tank as cap is removed. Am running now with cap half loose.


Have a new tank from kccampro ready to install if I ever get to it.