About 3 weeks ago, I was out running errands, and for the return trip, the car wouldn't start. I opened the hood, waited a few minutes, and it started up. Common behavior:
* If it's been off for more than a few minutes and in the garage or the shade, it starts no problem
* If it's been running (like out running errands), and I shut it off and try to start it soon after, it won't start. *especially* if in the sun and/or hot day.

On Saturday, for the first time ever -- and it was probly our hottest day of the year -- it just cut out at a traffic light. stopped and wouldn't start. had to push it.

Suggestions? Is this vapor lock? Is the solution...
* a new fuel pump?
* phenolic gaskets/washers for the manifold/fuel injector? (And if so, where can I get them?)
* just clean something out?
* Something else?

Thanks in advance for any advice you all have,
+scott

p.s. Rainflye, thanks for your advice on re-installing the front grille. Small black screws worked like a charm.

Do you touch the pedal when hot starting?

D-Jet floods very easy whenever the ignition key is on. If you think it's flooded, turn key off, hold accerator flat, crank it over and jump off when it fires up.

If you opperate the car like the owners manual says, Phil has your 1st choice fix.

You could also have a dirty strainer which should live on the bottom of the pickup tube. Partial blockage causes the pump to cavitate, espically when hot. More likely to happen if the tank is less than half fuel.
--
69 142S Overdrive + 69 164S Manual

Vapor lock to that extent is pretty rare when running such high fuel pressure.

I'd look to the coil.
--
-Matt I ♥ my ♂

The early Djet (including my 1971 142E) did not have the fiber insulating washers that Phil S. refers to. Volvo started adding the washers and thicker O rings some time late 1971 or 1972 to reduce the heat soak from the head, so Volvo must have become aware that vapour in the injectors was a potential problem.

The OEM fuel pump has a check valve which should maintain pressure in the fuel system on shut down. Maintaining fuel pressure at 28 psi should discourage the formation of fuel vapour. However, as the check valves age leak back will occur resulting in loss of pressure and the potential formation of vapour. Once the vapour forms, the re pressurization of the fuel system on restart will probably not result in a phase change of the vapour back into liquid form and the system will have to purge itself of the vapour before getting a successful start.

Matt, it's not vapor lock in the sense that a carb engine can have vapor lock. It's fuel vaporizing inside the injectors, not on the way to them. It's a known issue, which is why the phenolic washer / fatter O-ring kit exists.

I hear you, Phil. And, although I have driven D-jet cars through very high heat areas, I've never had a problem.

But an overheating coil can cause similar no-start conditions. Admittedly, it's rare for a coil to go bad, but don't forget these cars are now 40+ years old...

I should, however, have suggested my usual fix of 'keep a jug of water on hand dump it on the coil when things act up, if only as a diagnostic'

It happens too, and very much heat related.

--
-Matt I ♥ my ♂

Guys;

I defer to Phil's experience on this, but it does surprise me that vaporization occurs...after all...the fuelrail holds high (regulator output pressure) even after shutdown, when FuPu stops supplying, and engine stops using...and even if vaporization occurred behind the pintle, as soon as a restart was attempted and the pintle opened the first time, it would purge the vapors, liquid fuel would replace them and would allow injection to function normally...or do I have this wrong?

Cheers

Does anyone think the problem could be the coolant temperature sender?
Not the gauge sender, but the one at the thermostat housing.

Not impossible -- they can fail in entertaining ways -- but not likely.

Thank all! I checked the injectors and they don't have a fiber washer on them. I ordered a set from iRollMotors and will install them as you suggest Phil. Fingers crossed...

Most likely fuel vaporizing inside the injectors. What helps are a pair of phenolic washers arranged like this:

Bolt head
Steel washer
Phenolic washer
Injector mount
Phenolic washer
Head
Bolt threads

Adding the washers requires using a thicker O-ring on the head. Washers and O-ring should be available from iROLL Motors.