1998 V70XC - EVAP P0455/DCT EFI-611, Instant 0 psi After Engine Off. Related?

[VolvoOwl98]

If your hardware isn’t terribly rusty you can do the tank drop method. You have to remove the driveshaft and viscous coupler to get the clearance and then carefully lower the fuel tank, leaving the rear axle carrier in place.

Does this forgo having to partially disassemble the rear subframe? My main hesitation with that is not wanting to mess up the rear alignment as that’s been done recently.

Make sure you get the right pump. The Volvo pump is no longer available. The insert type pump is but is bit tricky to get into the cartridge, very different than the FWD pump

I’ve read through the topic of the pump disassembly and doing this, but wouldn’t it just be installing this unit available from IPD? https://www.ipdusa.com/products/23453/F ... 27-9470674

[scot850]

Just don't buy the Pro Parts Sweden AWD pump sold by a few retailers including IPD. They are junk. As are the URO ones.

This is not cheap, but I would hope as VAST are selling this it is a good quality unit:

https://vasttuning.com/product/p80-awd- ... -assembly/

If you want to try the through floor method, here is our friend Robert DIY's video on the subject:


https://www.google.com/search?q=1998+Vo ... iBcJc,st:0

Good luck on this. I did this on my 00 V70R while replacing the corroded and cracked rear subframe as a 'while you are in there' but at that time OE pumps were still available. I also did a write up on this. Abscate did find a way to do the rear end drop doing it only as a partial drop using threaded rods. Hardest part is getting the harness up to the top and through the hole into the rear floor. I think he cut and joined the wires.

Neil.

[VolvoOwl98]

Thanks for the tips/info about this! I wasn’t aware about that as an option for a fuel pump, and having done more reading on the VAST website I’m definitely going to go with their option for the fuel pump (and wire replacement kit). They have it as a recommended servicing piece and it’s $42 which isn’t bad, and who knows what the current status of mine are ‘:D

It seems like partially dropping the tank isn’t too bad and mainly requires lots of patience, time, and freeing agent for the nuts/bolts. It’ll hopefully also give me a better look at the status of EVAP lines back there to inspect and replace since I’m already in there.

[abscate]

Have a bore scope on hand to inspect the top and try to get as much fuel out as you can. you can lower the tank with a joack easily enough but fuel will come pouring out when you break the big locking ring open.

The release of the OEM fuel lines can be easy or a real PITA - you need a forked release tool either from NAPA or a fabbed one to release the fuel lines.

....or cut them and redo with NiCopp and good FIJ hose

Borescope - have a good look at the top of the tank and green lines to see how much corrosion before you start.

If it is gnarly up there, you need to drop the axle carrier and thats a big step - potentially a project killer. The six big bolts on the carrier like to seize into the casting and both the bolts and the casting can break up on removal - a real pickle.

the early 1998 has the FPR on the steering rack - your late 1998 will likely have canister evap in the rear of the car, and FPR inaccesible on top of the fuel tank with the 'return lacking' fuel pressure regulation system

[scot850]

The FPR (fuel pump regulator) is as Abscate says sits on the top of the tank in the later versions. It is incorporated into the return fuel line and was not sold separately. Both are now NLA and have been for a few years.

The FPR as best as I can see does regulate the return fuel line which splits to the LHS ejector pump (it is not electrical) which uses the return pressure to move fuel from the LHS to the RHS of the rank where the actual pump is (tank is a 'saddle' tank). The ejector also has the fuel level measuring for the LHS of the tank and the main pump also has a level sensor for the RHS. The system then works out the total fuel level for the whole tank. If one or other fails, you only get a measure for one side.

Neil.

[VolvoOwl98]

That’s good to know that the FPR is on the steering rack on the earlier 1998 year models… I think in that case I’ve mislabelled what side of the VIN split Saskia is on, since I’ve stared straight at the fuel pressure regulator when I was looking for the cause of my oil leak (turbo oil return line gasket and o-ring).

Fuel pressure regulator pictured on the lower-right side

It does also have the fuel pressure pulse damper (p/n: 9186278) on the fuel rail as shown in earlier photos.

I had tried to figure out what side of the VIN split based on the Swedespeed post “'98-'00 AWD Component Parts Listings” where there’s different propshafts (and other parts) based on if it’s an early or late 1998.

https://www.swedespeed.com/threads/98- ... st-7814390

It’s a production date 01/98, which thinking about it now should have been the first thing I checked

In reference to the canister location, if you’re referring to the charcoal canister it’s located in front of the driver’s side front wheel

I apologize for that misinformation… at least that info will be helpful to somebody else sometime

[VolvoOwl98]

Ordered the fuel pump assembly with the DW200 pump and the wiring kit from VAST tuning (many thanks to @scot850 for that info about the Pro Parts Sweden unit not being good).

Also ordered the sealing ring and assembly lock nut to replace with a weekend later this month zeroed in on my calendar to give as much time as possible in the likely chance things take longer than expected.

All that’s left now is to read up/watch the procedure until I can recite it in my sleep lol

[abscate]

You need to remove the viscous coupling (vc) to drop the tank, mark the bolts position if it looks like it has never been removed as the were balanced by Volvo at the factory by choosing different weight hex bolts. Mark all 12 bolts. 6 on the Vc to driveshaft and 6 from VC to differential

There are four big m10/12 bolts? That hold the VC to the differential. I need a long extension , like 30 cm to get to the top right one.

[VolvoOwl98]

Given the looks of things, I don’t believe the propshaft has ever been removed.

If I’m already going to be taking out the propshaft and VC I might as well give them some TLC. It being the early 1998 it thankfully has the u-joint which by my understanding doesn’t need servicing (I might get to replacing the the carrier bearing as it’s showing some dry-rot, or I may do it the same time I service the bevel gear CV joint).

Since the viscous coupler will be taken out, is there anything I can do (cleaning, lubrication, etc.) that can be done to help it last longer? I do sometimes get a metallic clunk when putting it into reverse from the freewheel locking which I’d like to mitigate as best as possible.

[Vova585]

Propshaft-look at the car, then look at your wallet and see if they are supporting any work for it now. If not, then just remove it and drive in fwd without any issues. If your budget and goals are able to support some spending- remove driveshaft and send it to Colorado driveshaft. They will replace cv, u-joints, speed ballance it and it will be amazing. I think i paid $600 last time with shipping. Each time they worked on my propshaft it lasted around 90k. Dont stress about bolts. I believe they are single use only anyway and might require "persuasion" to remove. Colorado driveshaft guys sell a kit with proper bolts or will be able to suggest proper alternative(your car is close to 30 years old, rust, dirt, dings, wear of bearings in drivettain-good luck with precision balancing each bolt to past hole. If you will be removing VC, replace front bearing in the housing and seal at rear diff. Replace rear diff oil.