HIi, hoping you all can confirm my thoughts on a hard start problem- I haven’t played with returnless fuel system yet and may be missing something.

Have a 2008 V70 3.2 with ~90K miles. Since 50k or so it has hard a fairly regular hard start (cranking 2-5 seconds before it catches), occasionally requiring a second start cycle to get it to start, but always starting. 90% of the time the second start of the day is easier, but never fires up as quick as you’d expect a hot car to on restart (even one that probably needs teeth to pass by a hall pickup to confirm crank/cam position etc).

Finally hooked up the laptop this week and confirmed, not surprisingly, that fuel pressure drops quickly after the car is stopped- generally from 50+/- psi running to 1-3psi 10 seconds after stopping.

Questions:
1) has anyone else ever checked, or could you check, to confirm that this fuel pressure drop rate is unusual / indicative of a failure?
2) Any experience with this failure?
My prime suspects are pressure accumulator/checkvalve (whatever we’re call it these days) or a leaky injector. Leaky injector is easy enough to diagnose (pull injectors, crank, watch for post-crank dribbles), and while I’d prefer to replace an injector to dropping the fuel tank and rooting around in there, I suspect it is the checkvalve because the car does not particularly stumble when starting…

Presuming the worst – any knowledge of replacing the checkvalve? Servicable separately, or am in in this for a fuel pump if it is my root cause?
Many thanks,
CW

 

Most likely needs a fuel pump. Volvo doesn't sell the various parts of the pump assembly separately

 

Looks like most models can access the fuel pump without dropping the tank; having trouble finding definitive answer on the web for '08 V70- anyone confirm/deny if it is accessible from the top?

Many thanks for taking the time to reply.

 

Nope, gotta drop the tank on the P3 cars.

 

Hey--Did you ever get this problem resolved? I'm having a similar issue with my 2009 v70. Long crank time/sometimes doesn't crank at first/then fires right up the second time.

Also--sometimes the push button start button is unresponsive when I put the key fob in and press the button. I take it out/put it back in/and it usually works the second or third try when this happens. Only does it occasionally.

 

Made a few minutes to fool around with this yesterday while putting on the snow tires.

revtimothy- not resolved yet but getting closer. do occasionally have same key fob issue. trying to ignore it and keep my AAA platinum current in case I need a tow home....

I have a friend who works at a national parts distributorship and he indicates his company, which sources one economy line and one oem grade pump has sold exactly one pump since this model was released, which has made me chase injectors leaking after shutdown rather than fault the pump.

yesterday, however, I pulled the fuel rail and did a few things, all of which point to the pump/checkvalve being amuck.

1. removed rail, inverted it, full of fuel, inserted tygon tube into bore where fuel line seals via o-ring, and put about 60 psi air into rail with blow gun. no leaks, drips or hissing. When blow gun pops out of tygon, the fine mist of fuel that covers the right side of your neck is vexing.

2. connected blow gun via same tygon tube to fuel pump line. pressurized it to ~60psi; it appeared to hold pressure evidenced by audible 'pop' noise when removing the tube form the fuel line. did not use a gauge (hindsight is ever so clear...)

3. after an inspired suggestion from the helper, brazenly connected tygon from fuel line to rail and cranked for short burst to see if we could better understand which injector was leaking. did this a few times. no injector leaks after cranking. however, the tygon tube was clear, and after filling the rail to the point where injectors sprayed nicely, and ending the cranking cycle, one could repeatably watch the fuel drain back out of the rail, through the clear tygon tube, and back to the tank.

My best eval of root cause, based on the finding at the end of point 3, though somewhat contradictory with point 1, seems to be 'bad check valve at pump.'

Any other thoughts? I would feel much better about dropping the tank to replace the pump if someone with a well behaving 3.2 could make a minute to hook up an scanner and monitor fuel pressure (via fuel rail sensor output) after engine shutoff and see that it holds fairly high (e.g. 30psi+) for more than a few minutes...mine falls right to 1-2 psi in less than 10 seconds...

Regards
CW

 

I have personally replaced two fuel pumps for this in P3 cars within one week. So that beats how many his company has sold. I have replaced one single injector in over 10 years working on Volvos. One injector across all years and models.

 

Next time. Check the pressure with vida and with a gauge. Then read the duty cycle. More likely the pump. Listen to ES6T. By the way. That's all, 2 within a week. lol :P

 

Haha yeah, that's all for me. We've done several where I work.

 

o.k., fellas. should i go ahead and have my fuel pump replaced? if i don't, then what will happen? could i get stranded? how much should i expect this to cost me?

also, any others have an idea about the key fob starting issue above?

 

Thanks ES6T, that was what I needed to hear.

Really appreciate your feedback and insight!

CW

 

Am curious, did your issue get resolved by replacing the fuel pump?

My car is a 2009 V70 3.2 approaching 50,000 miles, and in the last month has begun exhibiting the same symptom as yours. Much longer cranking times than normal.

A failing check valve in the fuel system makes complete sense. I am not a DIY mechanic with issues like this and have scheduled an appointment with the dealer. Would you recommend having them hook up the Vadis system after the car has been sitting all night and prior to their first start attempt? Otherwise I am afraid they'll get a long crank for the first, but not subsequent starts. My issue has apparently not progressed to the same level as yours.

Thanks in advance for helping me point them in the right direction. Hopefully it won't get lost in translation between myself, the service writer, and the mechanic.

 

We don't use VADIS anymore. But diagnosis is simple. Install a fuel pressure gauge. Start the car. Shut it off and watch the pressure bleed down.

 

Thank you. To be clear, are we saying that the check valve is internal to the fuel pump in these cars? I'm thinking the fuel pump itself is working because the car runs fine once started.

And as long as I have your help here---can you give me some idea about how well it should be able to hold fuel pressure after the engine is shut down? Is it 100% of normal running pressure, or is some bleed down ok? I guess I'm just looking for parameters. I'd like to understand a bit about what the mechanic will be doing/looking for so I can get a handle on the final bill. Of course I understand I may not have the same problem as the OP, but it sure sounds like it.

Thanks again. It's great to be able to ask a mechanic these questions directly instead of having to go through the filter of the service writer.

 

The ones I have had needing a new pump (yes, the check valve is part of the pump, not sold by Volvo), have bled down almost immediately. They had almost no pressure left after 2 or 3 minutes. It should hold much longer than that. As in overnight or longer.

 

Any further results on this? My 09 XC70 T6 suddenly started giving me long cranks on initial start and I've been trying to track down potential causes.

 

I too would be very grateful if any who have this same problem update us with your findings. My 2009 V70 3.2 has this problem intermittently and the dealer has checked the fuel pressure, having noted nothing abnormal. Of course the car started every time after sitting for two days in the shop. And there's no rhyme nor reason to it at home, either.

 

I don't know why I didn't check last time I was under the hood, I was curious if anyone else checked their fuel pressure sensor o-ring for leaks/damage. I'm going to check tonight and I am going to cross my fingers for luck. I'm still baffled by how my car went from short rapid starts to instantly having bad starts.

 

My car continues to have this problem intermittently. I wouldn't know where to look for that gasket / O-ring you mentioned.

Is there some other issue that would cause this problem? My dealer was unable to get it to replicate itself.

Please let us know what you find out.

 

We have this issue with our 2008 V70. Our solution: push the fob in; press the brake pedal and hold until the fuel pump stops running (at full pressure); press the start button. This works quite reliably.

Pressing the start button once without applying the brake will also run the fuel pump.

My old 1989 740 had a bad check valve too. I would turn on the key, and then wait until the pump stopped running before cranking it over.