8.1EFI fuel pump cooling

[tallyho333]

I have an 8.1L that runs fine except if I shut it off for 15 or 20 minutes. It starts hard and runs rough for a couple of minutes. It acts like it is vapor locking. I removed the down stream cooling lint that feeds into the riser, and there is no water comming from the pump. The feed side from the heat exchanger has water flow. Is anyone familiar with this pump cooling? Suould it just circulate water through the pump housing, or is there a thermostat to prevent flow in the pump housing?

 

[Don S]

Re: 8.1EFI fuel pump cooling

Volvo has a lot of different models of the 8.1. Which do you have?

 

[runngun80]

Re: 8.1EFI fuel pump cooling

Good luck with your repair. I don't have repair advise to offer, but at least you got Don S. to reply that he needs more info to give an answer and he did go thru the trouble of listing every 8.1. Getting his attention is half the battle, apparently he didn't like something about my post Saturday on a fuel pump failure and possible overheating.

 

[tallyho333]

Re: 8.1EFI fuel pump cooling

The engine model number is:
8.1GI-EF model 3869263
serial number 4012130695

It is a 2004 motor.

I am thinking of trying to clear the passage with compressed air, but I want to be sure I will not damage anything.

 

[gbeltran]

Re: 8.1EFI fuel pump cooling

There is no thermostat device of any kind in the pump housing. Water goes in near the bottom of the assembly and comes out near the top. If it's that corroded that no water is flowing thru it I have doubts that compressed air will clear it out. Can you blow thru the outlet house when the inlet is disconnected? Are the lines themselves clear of obstruction?

 

[Don S]

Re: 8.1EFI fuel pump cooling

I wouldn't use over 20 lbs of pressure. I would check the hose between the fuel cell and the riser first, and check the fitting in the elbow to make sure it hasn't plugged up. The exhaust risers is where the corrosion usually starts, and backs up into the hose as things clog up.

 

[tallyho333]

Re: 8.1EFI fuel pump cooling

OK Thanks. I can not blow through it in either direction with the hose disconnected from the riser, and the other removed from the heat exchanger. I will pull the hoses and remove the elbow fitting to check them. I won't have a chance to check this until next week, so if all goes well I will be able to clear it. If not I guess it is new pump time.

Thanks for your help.