Not sure on this one but something cutting off fuel

Post by **shiloh51933** » 01 Sep 2016, 08:44

Initial symptoms are restarting after a long drive it wouldn't restart right away if motor was still warm/hot. Then last night it dies out, I hook up fp gauge and no fuel pressure at key on. I swapped fp relay and nothing, I finally take my key outside to try to reset everything by locking and unlocking drivers door and fuel pump primes then it starts. Only difference now is a faint buzzing behind dash cluster area near climate control. It's a buzzing only an owner of this particular vehicle would hear. Never heard it before. I know some alarm immobilizer will let u crank ignition all day but cut off fuel. Some immobilizer won't let nothing happen. It will crank all day . Only weird thing is the car stalling out, I was thinking maybe two different issues like crank sensor/immobilizer but no CEL.
2000 V70XCse

Post by **shiloh51933** » 01 Sep 2016, 17:42

Does anyone know location of the immobilizer/relay?
I already swapped in a known good FP relay. I was thinking maybe crank sensor but I should a CEL.
This is a 2000 V70XCse with 160 on the odo.
I've also been getting poor gas mileage, only use it for city driving so not much hwy but 12mpg is kinda low.

Post by **abscate** » 01 Sep 2016, 18:57

I think the ME7 immob turns off spark only.

You have fuel pump supply voltage or fuel pump problem. Confirm by watching the pressure at rail.

Post by **Clemens** » 01 Sep 2016, 23:20

try the following: have someone turn the ignition key to start while banging on the fuel tank with a piece of wood a few time really good. If it fires up it is definitely the fuel pump. If not it might still be as abscate suggested.

Post by **shiloh51933** » 02 Sep 2016, 09:48

abscate wrote:I think the ME7 immob turns off spark only.

You have fuel pump supply voltage or fuel pump problem. Confirm by watching the pressure at rail.

When it died there was no pressure at rail, even during key on the gauge doesn't move.
On the wagons you have to drop fuel tank right, on the 850/S70 there was an access panel in trunk if I remember correctly and the hareness/plugs for fuel pump/sending unit. Do you know location of that stuff on the 2000 V70xc or do I have to crawl underneath the rear of car?

Post by **shiloh51933** » 03 Sep 2016, 10:55

Clemens wrote:try the following: have someone turn the ignition key to start while banging on the fuel tank with a piece of wood a few time really good. If it fires up it is definitely the fuel pump. If not it might still be as abscate suggested.

After further investigation this is what's going on. The front door actuators are triggering the immobilizer and in turn the immobilizer cuts off voltage to the fuel pump. I'm replacing the actuators in both front doors today and I'll post back my results after finishing installation.

When this issue first showed it's ugly face I thought security system malfunction after a couple of weeks of no start when trying to restart after a long drive. This no start symptom didn't happen every time trying to restart but when it happen I had been driving for a while. Then she actually cut off during operation and I was thinking possibly crank sensor. After testing for fuel at fuel rail I thought possible fuel pump or FP relay and swapped in good relay but no good. I reset the security system with key at L/F door lock and that worked initially but the actuators got worse.

Post by **jimmy57** » 03 Sep 2016, 11:34

The door locks have nothing to do with immobilizer. The alarm system will not power starter relay as its way to anti-theft the car but that would also be flashing the signals at all 4 corners on that car. Immobilizer reads key chip and fails to send key OK signal to engine computer.
When your fuel pump is failing the pump will often work randomly. You could convince yourself that peeing on the right rear tire twice makes it run due to a few start tries making the pump run on occasion.

Post by **erikv11** » 03 Sep 2016, 12:38

jimmy57 wrote: ... You could convince yourself that peeing on the right rear tire twice makes it run due to a few start tries making the pump run on occasion.

I've definitely been there, done that, in one way or another ...

Post by **j-dawg** » 03 Sep 2016, 14:02

shiloh51933 wrote: On the wagons you have to drop fuel tank right, on the 850/S70 there was an access panel in trunk if I remember correctly and the hareness/plugs for fuel pump/sending unit. Do you know location of that stuff on the 2000 V70xc or do I have to crawl underneath the rear of car?

FWD V70s have an access panel as well. To replace the pump on an AWD or XC, you have to either cut an access hole in the cargo area floor or drop the fuel tank.

Post by **cn90** » 03 Sep 2016, 14:12

I'd:
1. Jump the fuel relay (use proper jump wire, spade type ends and insert into 15 and 87 sockets).
2. Listen to fuel rail with screwdriver + ear (ear to the end of screwdriver).
If you hear fuel running, all it means is that there is fuel flow, but the pressure can only be checked with proper fuel gauge.

How many miles in your 2000 Wagon, I have the feeling your fuel pump is going South...