V70 start stall issue

Wrenchinjoe · Post by **Wrenchinjoe** » 16 Sep 2009, 09:40

When I tried to start the trusty V70 this morning, it turned over and the engine fired, then stalled. Tried again, same result. After 3 or 4 trys, it finally caught and ran fine. However, it has been doing that same thing for my wife all morning as she shuttled kids to pre-school, errands, and so forth.

No check engine light, and no other dash warning light, everything appears normal in the dash cluster.

We had the throttle body replaced last year under warranty, so I wouldn't think that is the issue.

Any ideas?

Thanks,

Post by **Ozark Lee** » 16 Sep 2009, 10:07

The next time it gives you trouble check for fuel pressure at the schrader valve on the end of the fuel rail. When the fuel pump relay starts to go bad it gets intermittent.

...Lee

Wrenchinjoe · Post by **Wrenchinjoe** » 16 Sep 2009, 10:51

Will do, thanks Lee.

BTW, where is the fuel pump relay located?

Post by **Ozark Lee** » 16 Sep 2009, 11:16

It is under the cover for the fuse box. There are some pictures of it here:

https://www.matthewsvolvosite.com/forums ... php?t=9681

...Lee

Wrenchinjoe · Post by **Wrenchinjoe** » 16 Sep 2009, 11:31

Wow! That is a great write up about fuel pump relays.

Thanks again Lee, I'll post back with my results.

Wrenchinjoe · Post by **Wrenchinjoe** » 28 Sep 2009, 14:06

Ok, since a new fuel pump relay is only $45, I just picked one up and popped it in. However, the start stall problem still occurs. It is an intermittant problem for now and we are still driving the car to and from school, grocery store, errands, etc.

I checked out a fuel pressure guage from AutoZone and went to a friend's house who is a volvo mechanic for a local dealer. His intent was to test the fuel pressure at the rail IF we could get it to exhibit the problem (this is what Lee recommended earlier as well.) Of course it started perfectly for him every time. (This has to be some statute of Murphy's Law?!)

JD hooked up his code reader to see if the ODBII had thrown any codes and lo an behold, it had one code. I believe it was P1081 (I think, I didn't get a good look at it). The explanation for the code pointed to Mass Air Flow Meter malfunction at any rate. JD indicated that if the computer receives faulty data from the MAF sensor it will shut down the injectors causing a start stall symptom like I am getting occassionally.

Question - Can the sensor be cleaned with some CRC MAF Cleaner, or is it a replacement item only?

Also, does this part have to be Volvo for $250 or will the Cardone reman item for $110 with a lifetime guarantee from O'Reilly's suffice?

Thanks.

volvomileage · Post by **volvomileage** » 28 Sep 2009, 14:53

its worth a try to clean the maf and make shure the connections are good..

just spray it and let it air dry never touch the components....

cleaning it gave one more year on the previous maf...

for the reman unit...honestly i c ant say..ive used boch units either good used ones or new units.maybe some other members can guide you on this subject.

cheers !

ianmacd · Post by **ianmacd** » 28 Sep 2009, 22:28

Just had the same problem with my '97 850.The advice given to me was the Air mass sensor,really an easy thing to try,see my posting,'97 850 stalling.Good luck.

Wrenchinjoe · Post by **Wrenchinjoe** » 29 Sep 2009, 07:48

Thanks for the feedback. I will try cleaning first and if that doesn't help, I'll purchase a new part. I hope to pull the MAF sensor this evening after work. Looks pretty easy to remove the unit from the air cleaner box.

Do you dissasemble the MAF unit any further to access the sensor wires inside for spraying, or do you simply spray the wires through the open end(s) of the whole unit?

Thanks again for all of your help.

WJ

volvomileage · Post by **volvomileage** » 29 Sep 2009, 07:57

no the maf itself does not need to be disassembled...just spray the element through the opening ......spray and then let air dry..never touch or blow dry

by the way if you buy an other one make shure you buy same as numbers on your original maf...i had a good luck with a good used unit but of course it your call

good luck