S70 T5 Vapor-lock when Hot

VolvoAffair · Post by **VolvoAffair** » 18 Jul 2019, 10:04

Hello:

Recently experiencing vapor lock when the temps are high. Typically, I just have to wait for things to cool off––but this is increasingly taking upwards of 6 hours.

Thoughts, comments, recommendations?

vovo850 · Post by **vovo850** » 18 Jul 2019, 12:51

In the carb days we would add a wooden clothespin to the fuel line.
Add a spacer to the carb, insulate the fuel line.
Some would add a electric fuel pump to help.
Which leads me to say that seems really odd, is your fuel pump good?
Because I never heard of vapor lock in a fuel injected engine.

Edit to add I should have added fuel relay, it may be going bad, getting hot and failing. It also would not allow a restart until it cools off. Might be closer to a vapor lock symptom as well. That is fairly easy to test, just swap the relay out.

Post by **erikv11** » 18 Jul 2019, 16:37

What he said - it's not vapor lock. Start by testing the fuel pump relay (jumper it), then the fuel pump.

Post by **bmdubya1198** » 18 Jul 2019, 16:41

I've heard of these symptoms in 240s, but never a P80. Is your fuel pump running? What's your fuel pressure at idle?

+1 on the fuel pump relay, those are common failure items. It's very possible that it's overheating and failing.