Hi Folks,

I have been lurking in the forum and finding some great information on my parent's 1979 Volvo 242. The car has been sitting in place for over 10 years, and I am trying to restore it back to its glory. I have replaced all the fluids and gotten the engine to run with starting fluid. I am having challenges with the fuel system, and wanted to see if I could get some assistance.

I have confirmed the fuel pump is working by jumping fuse 5 and 7. I have gone through the car and cannot locate the fuel pump relay or the 25amp fuse. I have taken out most of the interior console. I've located other relays, but not the fuel pump. As for the 25 amp blade fuse, I cannot find that either.

I've read that the Fuel Pump relay is located in the passenger side by the computer and the 25 amp blade by shock tower in engine bay. I've attached a few picks.


Passenger Side - by the computer and behind the glove box.

Not sure where the 25amp blade fuse is

Any suggestions on where I can look? Maybe tell me where the wire terminate, so I can possibly trace it? I am stuck and it is so frustrating

- Ton

 

A US 79 240 will have a CIS fuel injection system. The fuel pump relay is green and located under the dash on the drivers side. Earlier cars had a metal case on the relay from what I remember. There is no fuse under the hood on a CIS car. Your other info - white relay, or twin silver relays under the passenger side with a 25amp fuse under the hood - is valid for a 1983 and up LH (electronic) fuel injection system.

Good luck getting a CIS to run (properly) after sitting 10 years. The fuel system needs at least 65 psi to run - one of your first steps after you google CIS fuel injection and learn how it is supposed to work - will be to Pressurize the system and push the fuel metering plate up - listening for the high pitched whine of fuel being sprayed from the injectors. Then find a fuel pressure gauge that can measure line, control and rest pressures. There are a few easy tricks to clear injectors - They will not be spraying properly and the fuel distributor or control pressure regulator may not work either after 10 years.

In your photo - there is a small relay next to the headlamp relay - that's probably the relay for the "frequency" valve - that should buzz whenever the car is running. That valve works in conjunction with the O2 sensor to modify the control pressure. Control pressure pushes the fuel metering plate down - when the engine is cold there is less control pressure (modified by the control pressure regulator) allowing the plate to go higher for a given amount of air flow and deliver more fuel - like an automatic choke.

 

Hoonk,

Dude.. .Thank you so much for the detailed response and the extra information. This gives me a lot of information to look up and research. Thanks again.

- Ton