1998 V70XC - New fuel pump, troubleshooted 9470674, new wiring, and odd fuel gauge behavior (problem resolved)

[PatternFlyer]

Well, Vast pump has been installed on mine. Had to change two connectors to factory one.
Power connector on Vast didn't fit because. Fuel level sensor also didn't fit. (PPS Pump 2 exactly same connectors that can't be used)

I haven't done the installation kit yet, but got the power wire in from the battery to behind the rear seat. That rubber caps with wireloom is a good thing that Volvo did for extra wires to pass through the firewall.

Engine running, but need to check ECM-6120 engine cooling fan "FC) High-speed: signal too high.

Now the problem. Pump level sensor works off the two white wires. Fuel gauge on the dash shows empty (filled 3 gallons just in case if I have to take the pump out again). Miles to 0 shows 0.

Didn't cut wires, just routed pump wires inside and under the rear seat to get to the wire area.

Isn't the Red circled connector from the fuel sender/ejector?

Factory wires had one with black line (about 3/8" long"), isn't that supposed to connect to Vast pump level sensor wire that has black dot on it?

"Yellow" circled connector with yellow/red wire is to the fuel gauge, isn't it?

scanning showed fuel level sensor, signal missing DIM-0004

This Volvo thing is crazy.

Any idea what I did wrong?

[abscate]

The fuel sensor wires to the tank are two white wires that run to two Sensors in series. It’s pretty common on high mileage vehicles Fora sensor to fail open which wipes out the,whole gauge, reading empty or near empty I believe

Wiring upthread

[PatternFlyer]

The fuel sensor wires to the tank are two white wires that run to two Sensors in series. It’s pretty common on high mileage vehicles Fora sensor to fail open which wipes out the,whole gauge, reading empty or near empty I believe

Wiring upthread

Is the yellow circled connector for the fuel gauge on dash?
I am going to try by pass the ejector wires and plug the two from fuel pump directly to that to see if it at least read.

If not, is the fuel gauge a separately available part?

[Vova585]

Do not bypass anything without first learning theory of operation. It will be best to obtain a repair database(alldata, Mitchell for DIY). Find electrical diagram and see the theory of operation. With float inside the tank moving uo/down, it is likely changes voltage/resistance. I would hypothetically imagine that one wire is input of 5v circut or a ground signal. Based on the position of both floats(abs said it is connected in series) the resistance/voltage reports back to gauge vs ecu that in its turn sends signal to the gauge. By knowing what voltage/resistance you shoukd have on empty/half/full you will be able to correctly diagnose what is missing. However, if the system worked on prior fuel pump and now now..cause-effect is in the new unit or mistake in witing. Any chance you still have an old pump assembly and can transplant just pump into old case?(back in the day we used this trick on many VAG cars from 80-90's. )

[PatternFlyer]

Bypassing the ejector and connecting both of the white wires from pump directly to the wires on Yellow circled connector moves the fuel gauge to full.

Vova585,

both of them connected in series is the problem. they are resistors. one on the ejector is dead (0 ohm measured on the two wires from the red circled connector). So, the circuit doesn't work.

since I had fuel left over in the left tank (around 6 or 7 gallons), and added aboutr 3.5 gallons to right tank. Measured around 65 ohm right after adding 3.5 gallons. Now it shows around 20 ohms (move the car to where rear is high ground 24ohms, moving the car to where front is higher ground 14 ohms) that I think is because of the fuel being pushed from the left to right.

I can fill it up all the way and try driving until the fuel gauge comes down to around half or where the resistance become close to 160 since it is only reading half of it.

Main problem is the ejector (9470840, Skandix 1056561) not being available. If it was available, I would have replaced both.

[abscate]

The ejector rarely breaks as it is not an electrical pump, it’s driven by fuel pressure bypassed ftom the FPR. As long as the connections are tight, it wil transfer fuel

[PatternFlyer]

The ejector rarely breaks as it is not an electrical pump, it’s driven by fuel pressure bypassed ftom the FPR. As long as the connections are tight, it wil transfer fuel

Yes. that is what I am assuming right now. Just the fuel level sensor (resistor) line probably broke inside the tank.
Will have to make new wiring to just plug the level sensor from the pump to allow less work later. I hate to take those pins in and out of connectors!!

Until I have more time to do tank drop you did on this thread
viewtopic.php?t=100655&start=10

[VolvoOwl98]

Got things all sorted out with my fuel gauge being inaccurate!

Delayed post because life, but the issue ended up being the case where the connectors running from the pump assembly to the back of the metal cup that sits on the hole of the fuel tank access (the part secured by the bung nut) were loose/disconnected). Partially removed the assembly and bent the metal to tighten each of the connectors, reattached them to the flat part of the connector, and had to replace one that snapped from metal fatigue.

Replacement connector was a 2.8 mm Dorman Conduct-Tite Female Quickslide Terminal from AutoZone (or equivalent) for 22-18 gauge wires (link: https://www.autozone.com/p/dorman-femal ... e_set=true)

Parts that gave me trouble

What I used to replace the broken connector

I was in communication with VAST about all this, some things they suggested for securing the connectors also included securing them with a liquid glue, a two-part JB Weld, or using 3.1 adhesive heat shrink (which they said could be dangerous since you have to hit it with a heat gun). They also sent an update that all of the future units they're sending out have much stronger adhesive heat shrink on the connectors to help prevent this from happening.

(Also appreciated the kindness of a partial refund 'for my troubles' as they worded it, overall 10/10 customer service and looking forward to some future goodies to better the ol' Swedish Steed down the road)


Hopefully in the next week or so I'll do a full write-up of the pump stuff, electrical things, and helpful tips I learned during the whole process to condense things down in a way that's easier to track

[PatternFlyer]

Got things all sorted out with my fuel gauge being inaccurate!

Delayed post because life, but the issue ended up being the case where the connectors running from the pump assembly to the back of the metal cup that sits on the hole of the fuel tank access (the part secured by the bung nut) were loose/disconnected). Partially removed the assembly and bent the metal to tighten each of the connectors, reattached them to the flat part of the connector, and had to replace one that snapped from metal fatigue.

Replacement connector was a 2.8 mm Dorman Conduct-Tite Female Quickslide Terminal from AutoZone (or equivalent) for 22-18 gauge wires (link: https://www.autozone.com/p/dorman-femal ... e_set=true)

IMG_5220.jpg
IMG_5232.jpg

I was in communication with VAST about all this, some things they suggested for securing the connectors also included securing them with a liquid glue, a two-part JB Weld, or using 3.1 adhesive heat shrink (which they said could be dangerous since you have to hit it with a heat gun). They also sent an update that all of the future units they're sending out have much stronger adhesive heat shrink on the connectors to help prevent this from happening.

(Also appreciated the kindness of a partial refund 'for my troubles' as they worded it, overall 10/10 customer service and looking forward to some future goodies to better the ol' Swedish Steed down the road)


Hopefully in the next week or so I'll do a full write-up of the pump stuff, electrical things, and helpful tips I learned during the whole process to condense things down in a way that's easier to track

Good to hear that you got the gauge problem solved
I am going to take the left sending unit out some time this fall to resolder the wires.
Even my friend's 2015 V60 AWD also has similar problem. One level sensor doesn't work.

Did you tell them about incorrect connectors? the power & level sensor connectors dont fit the stock connectors on the car. I had to remove them and put the correct ones from original wires.

[VolvoOwl98]

Did you tell them about incorrect connectors? the power & level sensor connectors dont fit the stock connectors on the car.

Thanks for reminding me about that, just sent an email to them about that with a photo attached.