1998 Volvo V70 AWD Hard Starting

Post by **renns** » 29 Jan 2014, 05:26

My V70 has had somewhat random hard-starting issues on and off for a couple years. Perhaps once every week the car will fire when cranking, then immediately stall. Re-start attempts are always unsuccessful unless the key is turned off and then on again, at which point it usually re-starts fine the second attempt. Once in a while it will take 8-10 re-start attempts before starting though. Strangely, this problem hadn't occurred for 6 months or more, and then reappeared a couple weeks back. It doesn't occur on every start-up, but maybe every 5th or so. The check engine light is not on, and the last time I checked a few months back there were no codes present.

Any thoughts?

Post by **renns** » 29 Jan 2014, 11:02

I should add that this intermittent problem has been around for at least a year, maybe longer. The fuel pump was recently replaced, and it's a '98, so no fancy ignition key safety devices to worry about.

Post by **renns** » 30 Jan 2014, 16:41

Happened again this aft. Fuel pressure at the Shraeder valve looked fine - came out with a healthy blast when depressed. Not sure what the deal is, but after a few attempts, it always eventually comes to life. Just hoping to avoid getting stranded, so any ideas would be appreciated.

als98volvo · Post by **als98volvo** » 30 Jan 2014, 16:56

Check your MAF. I just resolved my same problem by replacing the MAF. May not be the problem but, it is quick and easy to test. Undo the plug on it and see if it starts, if it does, MAF is bad. MAF is located on the air intake just north of the air filter. Thing with a plug on it. Good luck.

Post by **renns** » 31 Jan 2014, 10:25

If it does start with maf disconnected, can it be reconnected while the car is running? That'd normally be bad practice, but I'm wondering if I'm stranded if this will work. Once the car is running, it performs fine, and has never stalled or left me stranded once started. Thanks for the help!

Post by **MoVolvos** » 31 Jan 2014, 23:26

_

Check Timing.

Blessings,

BKM
_

Post by **abscate** » 01 Feb 2014, 08:59

renns wrote:If it does start with maf disconnected, can it be reconnected while the car is running? That'd normally be bad practice, but I'm wondering if I'm stranded if this will work. Once the car is running, it performs fine, and has never stalled or left me stranded once started. Thanks for the help!

No, you don't want to do this. Idle the car for a few minutes, then drive back home carefully with the MAF disconnected. The ECU (engine computer) will use a look up table of drive parameters if the MAF is disconnected which will work fine.

Reconnecting sensitive electronic while energized, no.

Bosch only for the MAF, btw.

Post by **BEJinFbk** » 01 Feb 2014, 14:24

BKM98 S70 T5 wrote:_

Check Timing.

Blessings,

BKM
_

Incorrect timing would produce consistent issues.
Any codes showing? Sounds almost like a failing
sensor connector, but I'd expect a failed input to
throw a code.

Post by **MoVolvos** » 01 Feb 2014, 14:57

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Is there any roughness in the idle after it starts? Do you smell fuel after a couple of attempts at cranking? Does it attempt to ignite at all or intermittently during the cranking attempts?

Blessings,

BKM
_

Post by **renns** » 02 Feb 2014, 16:52

Thanks for the feedback. Just got back from a 600 mile trip in the car. About half the starts required multiple attempts, from 2 to 8 attempts. The other starts it fired up first try. To clarify, it does attempt to start on cranking each time, fires, and revs jump up to 500 rpm or so, then it dies. There's definitely fuel pressure in the rail. I don't notice excessive fuel odour, but I'm inside the car at the time with windows closed, so I don't know what it's like at the tail end of the vehicle. There is occasionally some roughness at idle as well, although I attributed that to the cold temps we've been having. Is that another symptom that points to MAF?

It's a tricky thing to trouble-shoot, as there is no way to tell if it's going to start on the next crank attempt. I suppose unplugging the MAF, and driving for a day or two might be a good check. If the start problem doesn't re-occur, then that's the likely issue.