99 S70 won't start...fuel issues? Fuel pump relay Topic is solved

STLcharlie · Post by **STLcharlie** » 11 Dec 2016, 17:50

Hi folks,

I've been such a beneficiary of reading MVS over the last year I thought it was time I tried to chip in. Such thankful to have everybody's help.

Currently trying to get my 99 S70 (no turbo, no mods) up and running again. 230K on it. I'm in USA. Have had it for only a year so past maintenance is an unknown.

I drove it halfway across the country last week and had zero problems (was feeling, listening for them constantly). Had the car sit out in the cold the last few days and it didn't want to start up. First time this has happened. Cranks fine and just a couple hours ago I was able to get it momentarily started and eventually got the RPMs up to 5k after flooring the throttle, but it keeps stalling out.

Torque doesn't give any codes from OBD! Very surprised. Though I've had P1081 (immobiliser) come up a couple times while trying to start it.

So far, I've checked:
-Battery + connections: cleaned, greased terminals and have battery on trickle charger. Solid 12.6V coming off a refurbished battery I bought in May
-Fuel pump + relay: I *believe* I can hear the pump on and priming 2-3s before and 2-3s after I try to start it. No funny noises from it
-Fuel pressure: pressed the small schrader valve above the engine and there was a small squirt of gas. Appears there is some pressure
-Spark: looks like there's spark since I could get the RPMs up
-Timing: have not checked yet but wouldn't this throw a code? Haven't taken a good look at cams, belt yet
-Air mass flow, throttle control: if busted wouldn't these throw a code as well? Haven't tried to test specific sensors because of this

What am I missing here?

I'm thinking this is mainly a fuel supply issue. I haven't changed the fuel filter since I bought the car and it's possibly gone far, far too long. Thinking that could possibly be enough of a pressure drop to restrict the fuel flow. It also has responded better on the first try...maybe after it's primed and has more pressure built up? Really hoping it's not a weak pump...

Top priority tomorrow is to change the filter ASAP and go from there (I need to do it anyway). Then I'm hoping it's not picking through and testing individual sensors...ouch.

Any thoughts, advice, experience is so very appreciated! Looking forward to getting a little more involved on the forums here...hoping to have this car awhile and it sounds like I'll have some more work to do...

Charlie

Post by **abscate** » 11 Dec 2016, 18:17

Welcome Charlie

A very common problem on these cars is a bad fuelpump relay. You can jump it with a paper clip. See the Volvo Repair Database or VRD.

STLcharlie · Post by **STLcharlie** » 11 Dec 2016, 20:51

Thanks for the quick response.

I guess the fuel pump relay issue seems a bit more common than I thought. Maybe I'll try that first tomorrow. The pump sounds like it's working though.

Should probably head to the junkyard soon to pick up some extra relays anyway...

Post by **cn90** » 11 Dec 2016, 20:59

Fuel filter...try to stick to Bosch or Mahle.

Relay, search forum for the photo of the jumper wire btw pins 15 and 87.

Post by **rspi** » 11 Dec 2016, 21:33

Don't get another bad old relay from the junkyard. Jump it with a jump wire or install a new Volvo relay.

You should have a strong burst of fuel at the rail not a trickle.

These relays should be replaced every 10 years to avoid this simple problem.

STLcharlie · Post by **STLcharlie** » 12 Dec 2016, 09:21

You guys nailed it! Can't believe I didn't try that easy paperclip jump before asking...

Will order the new relay as soon as my first paycheck comes in next month. Til then I'll let the car sit while I make a jump wire and/or grab a few freebies from the junkyard. They never charge for them.

I appreciate the advice on the fuel filter - was feeling desperate and ready to head to Autozone two blocks away for the $20 cheapest/worst option. Any others I might look into? I'm reading good stuff about all things Mann. Currently a good deal on Amazon as well.

Big thanks for helping me out here. Such a relief.

Charlie

Post by **cn90** » 12 Dec 2016, 09:53

I don't think the paper clip is a good idea, someone here almost burned his finger trying to remove it (current flow is more than the thin paper clip can handle ---> hot paper clip!).

So a jumper wire like the photo below (with inline fuse) is the ticket for now.
In fact, you can leave the jumper wire in there until you get the new relay.
The difference between the relay and jumper is mostly for accident: read it up, the relay somehow has a circuit to stop fuel flow after an accident; a jumper wire does not.
Get 1-2 relays from local junkyard or ebay. Stick to Volvo OEM relays.

Post by **abscate** » 12 Dec 2016, 10:40

: IMG_2029.jpg (59.79 KiB) Viewed 6235 times

Post by **xHeart** » 14 Dec 2016, 08:53

Morning woes.
Key at POS II, a spit of fuel at the rail (schrader valve) after each prime -- from OFF to POS II.
Could it be the same relay - PN 9434225?

Need a better note on way to jump?

Post by **abscate** » 14 Dec 2016, 09:08

It could be the pump is on its way out and it is working part time.

But...you can check for good 12V (that means battery voltage) back at the fuel pump to see if its a voltage supply problem first.