Non starting following shut off
 

Hi All,
First post but long time user of the forum as I have encountered many of the common problems with a 1997 V70R and the wealth of knowledge and help here has helped me fix nearly all. Thanks to all involved.

One problem has stumped me though for the 3 years I have had the vehicle and I could do with some new ideas.
Car is a 1997 V70R 2.3 turbo manual fwd, 212,000 miles approx.
Starts and runs fine with engine cold or hot. But if the engine has just been shut off, it will crank OK, but die without starting. This can be anything up to 4 or 5 minutes after shutting off. Will occasionally start OK, or maybe after several attempts, but usually end up walking away and waiting. That's the easiest way to manage the problem as I just make sure I leave the car the 'required' time. 10 minutes would always be enough.
Not so easy at the petrol forecourt though, as filling only takes a few minutes and then sometimes it's embarrassment time as I can't move off from the pump.

Anyway all suggestions welcome, but to save on all the obvious places I should look first, here is a list from memory of everything done in the last 24 months or so. Not all these were an attempt to solve this problem. There were other problems and general refurbishment going on. However, the parts replaced below made no difference to this problem so unlikely to have been the issue. Happy to revisit them though if required.

PCV replacement
Coolant Temperature Sensor
Thermostat
Coil, Distributor Cap, Rotor Arm (Bosch) (And Camshaft seal)
Leads (Bourgicord)
Spark Plugs (Volvo)
Cam Position Sensor (Bosch) (And Camshaft seal)
EVAP valve (Bosch)
MAF sensor (Bosch)
O2 Sensor (Bosch)
Fuel Pump Relay (Volvo 2nd hand)
Fuel Pump Relay (New)
Fuel Pump (Bosch)
Fuel Filter (Volvo)
Air / Oil filter (Volvo)
Immobiliser Antenna (Volvo)
New Battery
Injectors refurbished with flow, spray pattern and leak tested
Cylinders compression tested all good and equal

Also no codes logged, but these cars are early OBD so a bit limited in the modules covered by diagnostics.

Many thanks in advance,
Dave

Crank position sensor

check fuel injector connections are tight and clean

This is a random thought. Could it be the ignition switch? I know these can cause issues, but cant remember if this is one of them.

Thanks for the suggestions.
Crank sensor one of the things I was thinking, but was hoping the problem would develop so as to make the cause more obvious. However it's one of the few things not changed yet so will probably get one. Not sure if there is a way to test it but if it's intermittent a test may not show anything amiss.

Fuel injector connections. I guess you mean electrical connections Simmy. Yes, I should check those in the way you suggest.

Never thought of the ignition switch as an issue. I did just do the immobilliser
antenna which surrounds the switch as I know these can break down, but worth checking the switch is sound too.
Will update with any discoveries.

Faulty crank sensor symptoms are

Starts without any problem when cold

Won't start when hot and needs to be left to cool down

The 850 crank sensor isn't difficult to change. I had a Mercedes S-Class that the gearbox had to come out to change the crank sensor as it has seized in and the only option was to remove the gearbox

does your fuel pressure hold for at least 20 minutes after you shut the engine off? If it all leaks away after a couple of minutes after shut off , look at the fuel pressure regulator or one way valve in the fuel pump .

Check the security of your induction hoses as well. I had a similar issue that stumped me until I saw the hose on the throttle body was not secure and letting in unmetered air.

Thanks for the further suggestions. Crank Sensor on it's way. Low cost and easy to fit.
You mean fuel pressure at the rail Clan?
I have tested pressure there, but never thought to do a test after shut off.
Just tried it, warmed car up and had about 2.5 bar when shut off.
Came back after 20 minutes and had about 1.6 bar. I guess this is holding some pressure. Haynes manual says 3.03 bar for these systems, but to be fair I only had a cheap dial type pressure gauge. More of a comparative check really to check for loss of pressure.

Me too, I bought a cheap smoke-tester. It's proved it's worth several times since. Runs on, of all things, baby oil.