Hot Start Issue - 2000 V70 XC 2.4T

[WootFatigue]

2000 V70 XC 2.4T, imported Canadian market car with around 200k kilometers. I only mention that because you never know if something was a little different between markets.

Fuel pump was replaced by the dealer when the tank was dropped to replace rusted fuel lines - although I’m not sure which brand they used. My uncle, who owned the car before me, was kind of an open checkbook when it came to maintenance and basically said yes to anything the dealer recommended. In the last few years of his life he tossed $27k in parts and labor into the car, which is why I’m so adamant at keeping it running.

My problem is a hot start issue. The car will start up on the first crank when cold, but requires multiple attempts at cranking when warm - yet it will always start eventually. Reading forums lead me to believe it was a bad check valve in the fuel pump, but in an amateur mistake I trusted that without doing proper diagnosis.

I did pick up a fuel pressure gauge and it is quick to build pressure and holds it once the car is shut off for awhile.

I’ve tried jumping the fuel relay but the problem persists.

I’ve also changed out the engine coolant temperature sensor, as I was told that if it was reading cold when the engine is warm, it might flood the cylinders with too much fuel. The problem persisted after that.

The possibility of it being a problem with the immobilizer was considered, but that was also replaced when the car was re-keyed at some point for reasons unknown to me.

My current theory is interference from an old starter on the crank position sensor - which sounds wild, but apparently others have had the same issue and solved it by replacing the starter or re-routing the CPS wiring. I’ve tucked the wiring away a bit and it seems to have improved, but I don’t think I’ll know for sure unless I change out the starter.

Any recommendations would be greatly appreciated.

[xanthefin]

Speed / RPM / Crank sensors example does or can have symptoms where they act slightly different in temperatures but you can see it if during running there comes any weird readings. I am not gonna sign it though as reason.

For fuel.. i bbelief you have there easy access to fuel rail where at the end (?) has small valve where to check against pressure. With ignition on i get some 1.5bar but when i tried crank it goes higher to 3 bar.


I want just ask does cranking sound any different when problem and or not problem?

[WootFatigue]

Speed / RPM / Crank sensors example does or can have symptoms where they act slightly different in temperatures but you can see it if during running there comes any weird readings. I am not gonna sign it though as reason.


I want just ask does cranking sound any different when problem and or not problem?

No weird readings but I've been keeping an eye on my starts to see if the tach bounces at all.

Cranking sounds strong and normal although there is sometimes a loud thump or low bang when it finally gets going.

[xanthefin]

Speed / RPM / Crank sensors example does or can have symptoms where they act slightly different in temperatures but you can see it if during running there comes any weird readings. I am not gonna sign it though as reason.


I want just ask does cranking sound any different when problem and or not problem?

No weird readings but I've been keeping an eye on my starts to see if the tach bounces at all.

Cranking sounds strong and normal although there is sometimes a loud thump or low bang when it finally gets going.

Its general good tip look RPM jumping at cranking but on example 850 this is not possible to see sadly. I had starting issue due distributor cap and rotor recently and i tried but the instrument panel is not so responsive one for that. (Though footnote for 2000 year models.. i cannot verify)

abscate, scot850 and many others masters here sure knows something for these models possible issues.

[scot850]

Fuel pressure for your car should be 50psi and up to 60psi on a newer pump.

What brand of coolant temperature sensor did you use? This is one part where we recommend Volvo part only due to many issues with aftermarket parts.

Check the connector and wires at the connector for the coolant temp sensor for corrosion and damaged to the wires.

I am concerned at the loud noise/bang when it starts. Is the s physical thing like say a muffler hitting the underside of the car or the engine has a broken mount allowing it to know, or is the bang like something like a backfire?

Being a 2000, your car has a variable cam position sensor (CVVT) on the inlet cam near the timing belt. If this is acting up it can cause timing issues. Hard to diagnose.

The engine needs 3 things, air, fuel and spark. If it is getting all those then it could be a multitude of electrical gremlins.

Are you getting any codes from the car or engine check light? If you don't have a OBD2 diagnostic tool, it is worth finding out if there is someone who has a decent one. Some US parts stores used to do these checks for you. As it is an engine issue, most readers should be able to see any codes for issues or pending issues.

Neil.