Fuel pump relay question Topic is solved

Post by **dalel** » 17 Nov 2018, 17:35

Thanks in advance for pardoning my ignorance.

When swapping fuel pump relays, is it really necessary to unplug the battery? And if so, may ask why?

1998 V70 FWD non-turbo

I have had the classic "runs until warm but then doesn't want to run when restarting" problem. About a year back I was getting p0455's. Replaced the purge valve and everything seemed fine through the winter. It threw p0455 again in summer. Replaced the gas cap and everything seemed fine. No more code but once at the end of summer it did run really rough after restart. Just this week I had the distributor cap, rotor, wires and plugs replaced.

I think everything is good but I'd like to put a Volvo original fuel pump relay on. (Pretty sure the current one is KAE.) When I mentioned it to an independent shop they said it would take a half hour to switch it because of resetting codes. So I'm just getting more confused.

Much appreciation to anyone who will bother to ignore my ignorance.

Post by **wizechatmgr** » 17 Nov 2018, 18:35

No, isn't necessary to unplug the battery as it only has power when the ignition is at "ON" if I remember correctly.

Would recommend checking the coolant temp sensor's resistance at the temperature you're having the issue at. Abscate has the chart laying around somewhere as to the anticipated values you should be receiving at various temperatures.

Post by **dalel** » 17 Nov 2018, 19:07

Thanks for the reply.

It doesn't happen often enough or long enough to check resistance. Soooo, I'm now just replacing easy stuff. Shoot, can't imagine that a couple of new parts could hurt.

Post by **abscate** » 17 Nov 2018, 19:34

It’s good practice to remove the negative terminal on Amy electrical service item.

To get the fuel pump relay, you have to open and. Remove the fuse box top layer. You have
to beccareful with that if it’s live.

Post by **wizechatmgr** » 17 Nov 2018, 20:40

Also don't drop a screw from the fuse box cover into the great beyond... You will never find it again, but you'll always hear it rattle =)

WhatAmIDoing · Post by **WhatAmIDoing** » 18 Nov 2018, 00:25

I've never disconnected the battery to replace a fuel pump relay. It only gets power when the key is on, so I don't worry about it. Replacing the relay should take no more than 10 minutes.

Post by **abscate** » 18 Nov 2018, 01:21

I think everything is good but I'd like to put a Volvo original fuel pump relay on. (Pretty sure the current one is KAE.) When I mentioned it to an independent shop they said it would take a half hour to switch it because of resetting codes. So I'm just getting more confused.

A half hour billed time is probably reasonable, given most will bill you a one hour minimum, which is also a fair and reasonable practice to cover front, tech , and back end shop charges.

Resetting codes is a curious statement, though. A pro shop will remove the negative battery terminal after hood up, which will reset your ECU and clear codes.

I just bumped a procedure for this with photos in the 1wagon thread got someone else by the way.

Post by **dalel** » 18 Nov 2018, 14:32

Thanks for all the help. I don't always post a lot but I do read daily and you guys are great.

Post by **cn90** » 18 Nov 2018, 16:07

- I have a Fuel Relay (Volvo OEM) in excellent condition.
I don't have my 1998 S70 GLT any longer.
You can have it for free, just pay shipping.
PM me if you want it.

Post by **dalel** » 06 Dec 2018, 15:24

Thanks to cn90 for the relay. Haven't put it in yet but its great having one that says "Volvo" on it!