Having Hot Start issues

[Centella]

Volvo Penta 5.7 Gxi-F always starts perfect when cold, but when it gets warmed up, you need to prime throttle (no need full open, 1/4 may be enough)
It Starts again fine if it sits for maybe 2-3 hours after running (requiring longer in summer time).
idle RPM are stable around 700 RPM.
Have no DTCs active and ECU triggers them whenever you disconnect a sensor e,g ECT.
Replaced thermostat, ECT, IAC, TP, MAP, Spark plugs, Ignition coil, FPR, Fuel injectors...
Fuel pressure is correct and engine performance as well, it reaches 30 knots easily at 4200 RPM, didn' t go further though it still has some RPM there.

Any thoughts on what might be happening ?

 

[alldodge]

Welcome, looks like your using a parts cannon on the motor. Replace everything and you still have a problem. Replacing parts can add to and mask what is really happening. Must say you must have plenty of money to throw at it

What is motor serial number?

What was your fuel pressure readings when it would and would not start?
What is the MAP, ECT, TPS and IAC when cold and when it won't start?

What scanner are you using?

Did you replace parts with OEM of aftermarket?

 

[Mc Tool]

Is that really a problem tho ? I have had motors that did like a wiff of throttle to start hot .

 

[Centella]

Welcome, looks like your using a parts cannon on the motor. Replace everything and you still have a problem. Replacing parts can add to and mask what is really happening. Must say you must have plenty of money to throw at it

What is motor serial number?

What was your fuel pressure readings when it would and would not start?
What is the MAP, ECT, TPS and IAC when cold and when it won't start?

What scanner are you using?

Did you replace parts with OEM of aftermarket?

I found BOSCH original equivalences for fuel injectors, MAP and FPR.

 

[HiWard]

I found BOSCH original equivalences for fuel injectors, MAP and FPR.

Do you have a part number for the Bosch replacement injectors?

I've occasionally had hot start problems on my 5.7 GXi-HF and when it finally starts there's a smell of fuel from the exhaust. I suspected leaky injectors, so I cleaned them and have not had major issues since.

 

[alldodge]

I found BOSCH original equivalences for fuel injectors, MAP and FPR.

If you bought the injectors from Ebay or Amazon than most likely they are junk. Injectors can not be rebuilt only replaced

 

[Centella]

Do you have a part number for the Bosch replacement injectors?

I've occasionally had hot start problems on my 5.7 GXi-HF and when it finally starts there's a smell of fuel from the exhaust. I suspected leaky injectors, so I cleaned them and have not had major issues since.

Apologies for delayed answer , BOSCH part number for the injectors is 0 280 156 081, they come in original BOSCH package, made in same Brazil factory as the Volvoones but at almost 10 % of the cost in comparison. It is like you buy 8 BOSCH for the prize of 1 Volvo and can have some drink to cheer included

 

[Centella]

If you bought the injectors from Ebay or Amazon than most likely they are junk. Injectors can not be rebuilt only replaced

you can find them easily in a car spare parts shop e.g https://www.autodoc.es/bosch/689370

 

[alldodge]

Need a scanner
Going to need some actual readings and measurements

Is fuel pressure between 50-60 psi from idle to WOT?

Use a Noid light to see if injectors are turning on/off when cranking/running and that they don't stay on with motor off and key on