1999 Volvo S80 - Cranks but Wont Start - Fuel Pump Relay?

ohmfab · Post by **ohmfab** » 07 Jul 2008, 10:37

Hello all,

My S80 sat in the garage for a few weeks and now it will not start. It cranks but will not start.

So far I have checked the fuses and all are okay. I also checked the fuel pressure which was only 30psi with the ignition turned on. I think it should be about 54psi (375 kpa).

Does anyone know where the Fuel Pump Relay is located on an S80? I am guessing it is in the Rear Electronics Module in the driver's side of the trunk but none of the relays there are marked.

I will check the ignition coils next but I think it is getting spark as I hear it 'try' and start when it is cranking.

At first I thought it might be the ETM so I unplugged it and tried to start the car -- oddly enough with the ETM unplugged it started and ran for about 5 seconds. Still not sure what this means and maybe the ETM is partly to blame as well.

Any other items to check?

Thanks to all,

Omer
99 S80 2.9 non-turbo 170k miles

Post by **billofdurham** » 07 Jul 2008, 12:51

The fuel pump relay is in the passenger compartment relay box.

Bill.

ohmfab · Post by **ohmfab** » 07 Jul 2008, 13:22

Thanks, Bill.

I hope it is as simple as replacing this relay.

Omer

les & reilly · Post by **les & reilly** » 07 Jul 2008, 15:47

hi,
if your relay is the problem, it may bot be necessary to replace it. more than often the contacts arc similar to welding and stick rogether.

all you need to do is take the cover off the relay carefully, and use a small piece of fine sand/glass paper to clean the contacts. be carefull not to bend the relay works, but by doing this it will be as good as new.

good luck

ps it may well be worth charging your battery, remebering to disconnect at the terminals. i say to chrge the battery because this also may be the cause, when youve disconnected the circuit board and it starts, it may be because the circuit board may take some of the battery power.

get back to see how you got on,,

les ne uk

ohmfab · Post by **ohmfab** » 08 Jul 2008, 10:49

Looked into the issue more last night. I took the relay out and just jumped the bottom two connections where the relay plugs in to have the pump on all the time. I then checked the fuel pressure and it was 60psi. Good sign that the fuel pump is OK.

I tried cranking the car again with the relay bypassed and it still would not start.

Next I checked the ignition coils. I checked them one at a time by connecting to the #1 coil connector, stuck a spare plug in and layed it across the valve cover so it would ground. Every coil produced a spark. I haven't checked all the connectors to see if maybe one of them is corroded, that is a possibility.

I pulled the spark plugs out and the rear ones for cylinder 5 & 6 were more wet than the others. Perhaps the injectors are locked open, although I changed the #6 injector a while back. Another thing to check.

Spoke with the dealer this morning and they said they have never seen an ETM cause a no start situation. I almost believe them. I have them check my vin to see if any updates were done to the car and they said no. I suppose if I get it started I'll have them do the software update but they clearly said they will never replace the ETM unless they get a hard failure code.

I'll look into it more today. Got a new relay and set of plugs from the dealer and hope it does the trick....

The car has been relatively trouble free for the last 70k miles/3 years I've had it so I won't complain too much.

Thanks for all the suggestions!

Omer
'92 Sentra SE-R w/lots of mods http://www.ohmfab.com
'99 Volvo S80 170k miles
'02 Ducati Monster S4

ohmfab · Post by **ohmfab** » 15 Jul 2008, 10:12

I put in a fresh set of plugs and swapped the fuel pump relay and after about 5-7 cranks it started right up. Idle was still a bit erratic but I drove it a short distance and everything seemed to be okay.

I took it to the dealer the next day and got the ETM software updated and the idle went up from ~700 to 900. Now most of the time after the car is warmed up the idle stabilizes at 900 although I sometimes do see it go back down to 700 but it is stable.

Thanks for everyone's help. I think the combination of the fuel pump relay and a fresh set of plugs got me going again for under $50.

Omer