Everyone realizes that the timing belts need to get replaced before they bust.

Yet there's a lot of activity because of busted Fuel relays throughout the
Volvo Nation. In the 4 Cyl Red Block world it's called the RSR (Radio Safety Relay) and in the 850 5 Cyl world it's called the "main fuel relay".

There's posts galore everywhere on Brickboard about these relays which are an essential component of Bosch Fuel Injection, namely to shutdown fuel when the engine quits/ or there's a crash etc. The RSR and "Main Fuel Relay" are another name for a safety device. The bad news is when the relay quits, the engine is off.

Volvo didn't make long term provisions for servicing it seems, and the Fuel relay
obviously has a service life expectation just as the timing belt.

Perhaps people can assign a number of miles, years or hours, to decide when it's time to be proactive and get a NEW fuel relay, and not some tired replacement from the boneyard?

Comments?

Bill

Interesting question.. In the aviation world everything is tracked as far as serviceable life is concerned, and replaced accordingly. Honestly, $50.00 doesn't seem too bad a price to pay for piece of mind, especially if these are known to fail even after a successful start-up. Its unfortunate that we have no data like this readily available for the automotive world. I would suggest that local driving conditions would also play a role in the longevity of these components.

In the Honda/Acura world this problem also occurred with most of their products made in the late 1980's-1990's, perhaps longer, (I haven't owned any newer than mid-1990's)In this case, the relay was prone to fail on hot days usually at first start-up. I do not recall of it failing after you got the engine to start however. Again, this was only a Honda thing.

Just a few thoughts...

$50 for a replacement relay, to be proactive, is quite an expense. If I find a non-working one, perhaps I could send it to you and you can take the cover off. I suspect it is just a bad cap, which radio shack probably has on hand for $5 or less.

Also, the diagnostics seldom point to the main fuel relay. The best way is to check the spark plugs for dryness or pull all 5 injectors and let them inject into plastic cups with the starter engaged and the coil wire pulled.

Hi Klaus,

Is that $50 for OEM or some chintzy after market relay?
Yes $50 isn't cheap for being proactive. My point is that some stuff dies with old age and after so many cycles, and the fuel pump relay failure may generally start with intermittent ragged operation and finally killing the fuel altogether.
The $50 becomes a bargain after the fact when your 19 year old relay dies and you
lose fuel in the passing lane on the highway in some thunderstorm. Murphy has a way of rubbing it in. It's not the same as losing power to the cigar lighter.

I'd appreciate any failed fuel pump relays, to see just what happens.
As I understand there's a fair amount of current going through those points,
perhaps over time the points become toast. Relays have a service life usually of so many cycles, and aging has additional issues.

We change timing belts and water pumps before they die, why not the fuel relay that will kill the engine when it dies. But when? how many miles/years is the
question. Does the Brickboard archives have enough fuel pump relay stories to
convince you, and how many relays get changed without a post, since it's such a
well known issue?

Bill

When my cigar lighter fails to work, I pull over and start kicking the car!

I carry a spare fuel pump relay in the glove box.

I do not carry a spare main fuel relay, those are kept reasonably cool in their position. Nor do I carry a spare fan relay for the same reason. BTW, 1996-2000 have a spare fan relay in disguise as a SAS blower relay, so I guess there is a spare...