2007 S60 Repeat Intermittent Starting Issue

[soulvoid21]

Hey all, I didn't want to revive a dead thread, so I thought it'd be best to start a new one. I'm, once again, running into an intermittent hesitant starting issue. Original thread below from 2017.

viewtopic.php?f=9&t=80543&start=40

The fix last time, after somewhat firing the parts cannon, was found that the starter had high amp draw. Replaced starter with a Volvo starter from FCP and the issue was gone (link below). Fast forward to about 2 months ago, around 2 and a half years later, I noticed it stumbled to start slightly leaving work, and it was only idling around 400 RPMs again. Revved the engine up to around the 1500 RPM cold idle and it held like normal, then idled down and ran fine.

It's now repeating the same exact symptoms as last time. Nearly every start is hesitant (but not all), cold or hot, not weather depended. Since it has been around 40k miles since this issue, I figured it was time to change the spark plugs , so I got a set of Volvo plugs from FCP. It seemed to help significantly, for a few days I had no problems starting the car, and even started getting somewhat better MPG and noticed more throttle response. But now that the plugs have been in for a few days, it's still having a somewhat hard time starting and won't always go to the cold idle RPMs on its own every time.

With everything happening right now with the virus, it's hard for me to get to my mechanic to have him test the draw on the starter again (and those are expensive to buy one!). What are the chances that this is actually the starter again? I forgot until just now that FCP has their Lifetime Replacement Promise, so I could order one and just try it, but I'd rather not if I don't have to.

Parts replaced previously:
- Cam position sensor
- Crank position sensor
- Ignition switch
- MAF Sensor
- Spark Plugs
- Coil Packs all inspected, no cracks or white powder. All terminals are still extremely clean. This was a very very well kept car.
- Starter - (https://www.fcpeuro.com/products/volvo- ... m-36002496)
- Battery is newer and strong still. Has never died or gotten low on me. No after market stuff like stereo or anything. Car is completely stock.

[soulvoid21]

I did just double check all the terminals at the battery. There's the main wire coming from the positive terminal, and then another small wire on a second post. The smaller wire terminal nut was pretty loose. Tightened it and restarted the car a few times. It didn't hesitate in the 10ish times that I restarted it, but the car normally starts regularly if it's restarted immediately. Once it sits for around 20 minutes it happens. Will update if this fixes it.

[jimmy57]

Find out the predictable times it does and then have someone cycle key off three times while you depress fuel rail schrader valve on the test fitting. If the fuel runs out on second key cycle then stop. Now turn key on one more time and start it. If it consistently runs ok after this fuel vapor purge then replace the fuel pump. The check valve on fuel pump is leaking and the dead end fuel system can only purge the vapor in lines by engine running crappy until the vapor passes through by injector cycling (or by depressing schrader valve and short cycling the pump).

[soulvoid21]

Find out the predictable times it does and then have someone cycle key off three times while you depress fuel rail schrader valve on the test fitting. If the fuel runs out on second key cycle then stop. Now turn key on one more time and start it. If it consistently runs ok after this fuel vapor purge then replace the fuel pump. The check valve on fuel pump is leaking and the dead end fuel system can only purge the vapor in lines by engine running crappy until the vapor passes through by injector cycling (or by depressing schrader valve and short cycling the pump).

Will do. It does it nearly every morning now. So I may have to do the vapor test a few times to be sure. I'm also going to wait to see if it was just the loose terminal. After going to the grocery store and such today, it seemed to be OK. But that was a very short test period. I will report back what I find.

[darrylrobert]

my 2001 xc70 is doing almost the exact same thing, no codes hard starting, but only when hot. I completed a short test drive yesterday (midday 22c) to the shops and it performed well until i decided to get some take out late afternoon (temp 20c). drove to the food place and waited less than 10minutes and it hard started, took around 5 seconds to start, i switched off and tried again and it will start within 2seconds. Its very hard to fault find because it strikes at the worst times, its really quiet now as most people are staying home but yesteday was blowing a hurricane so not great. Get home and it will start great even after waiting. I was thinking some type of radio interference from solar activity?. Have you got the "start inhibited, please try again" message at any time??

[soulvoid21]

my 2001 xc70 is doing almost the exact same thing, no codes hard starting, but only when hot. I completed a short test drive yesterday (midday 22c) to the shops and it performed well until i decided to get some take out late afternoon (temp 20c). drove to the food place and waited less than 10minutes and it hard started, took around 5 seconds to start, i switched off and tried again and it will start within 2seconds. Its very hard to fault find because it strikes at the worst times, its really quiet now as most people are staying home but yesteday was blowing a hurricane so not great. Get home and it will start great even after waiting. I was thinking some type of radio interference from solar activity?. Have you got the "start inhibited, please try again" message at any time??

I have never received any codes or messages on the display. The only strange thing happening, and it's happened since I purchased the car and have read it's somewhat normal. When I get in the car, even if I don't touch anything to the ignition, the RPM and sometimes the speedo will jump up, like it had a random static charge.