Sudden hard start issue

Redbox · Post by **Redbox** » 19 Dec 2025, 09:38

This is kind of a long story, but I'll try and shorten it up. 04 V70R has been parked for the last couple of years with occasional short runs. I just got it on the road a couple days ago, and it had been running perfectly. Yesterday it started to crank a while before starting which is not normal for this car. It happened several more times during the day, sometimes stumbling with poor throttle response till it picked up. It runs fine after it gets going. I'm trying to get VIDA set up on my laptop to check things out, but not ready yet. No messages on the dash.
I've made several repairs over the last few years, but there are very few miles on them. I replaced the fuel filter, pump, pump control module and battery. This sounds like a fuel problem to me, but not sure where to start. From sitting so long, I can imagine corroded wire connectors , and I know that mice have been in the car.
I love being back in this car, but this is spoiling the reunion.

Post by **Blacklab467** » 19 Dec 2025, 13:54

Check battery voltage, this is extremely important, not only for cranking. It sounds like your battery is barely strong enough to start the car, not the correct voltage to run the computers etc.

lrock · Post by **lrock** » 19 Dec 2025, 23:12

check your evap purge solenoid in the engine bay, make sure it isn't stuck in the open position and your gas cap seal.

i had a bad solenoid, would have to crank it a few seconds to start, and would take about 3 tries to get it to catch any time i broke the seal on the tank.

Post by **vtl** » 20 Dec 2025, 08:10

Read the fuel trims with any OBD reader, it will tell if there an air leak. On top of the battery check, follow all the red cables and check for oxidation, which is common. One spot to check is in the REM area, left rear corner of the car. Another spot is fuse box under the hood - that one will have some oxidation most likely. Check the engine grounds: one near starter, one on the back of valve cover. Check fuel pressure and fuel pump duty cycle.

Post by **volvolugnut** » 20 Dec 2025, 09:25

I always suspect bad fuel if a vehicle has sat or little use for a couple years. I suggest a tank drain, refill; and fuel treatment.

Modern fuel has shorter shelf life than the old stuff. A recent story I read was a startup with decades old gas that ran fine. It was a carb, but still surprising. As I recall growing up on the farm in the 60's, there was no worries about parking equipment for the year and starting the next year.

volvolugnut

Redbox · Post by **Redbox** » 20 Dec 2025, 17:21

Thanks for all the feedback. I didn't have much time to work on it today, but twice I tried turning the key on for a few seconds before cranking and it started right up. I pulled the air box out and plan to check cable connections. I checked all the fuses under the hood and in the dash and plan to dig into the electrical stuff in the back tomorrow. Battery tested at 12.4. Charging seems fine and battery is less than a year old.

Post by **vtl** » 20 Dec 2025, 17:39

Redbox wrote: ↑20 Dec 2025, 17:21 Thanks for all the feedback. I didn't have much time to work on it today, but twice I tried turning the key on for a few seconds before cranking and it started right up. I pulled the air box out and plan to check cable connections. I checked all the fuses under the hood and in the dash and plan to dig into the electrical stuff in the back tomorrow. Battery tested at 12.4. Charging seems fine and battery is less than a year old.

Leaving the key in POS II for 2-3 seconds is what I do now. I have a hard start otherwise. Fuel pump, filter, pressure sensor are all new. PEM is not new, and I have a spare somewhere. But it was relocated to the trunk.

Post by **DavidE7** » 30 Dec 2025, 10:00

If you find a new battery is needed - get the slightly larger H8 size instead of the H6. There are threaded holes in the trunk floor for the mounting clamp to fit both sizes and the extra cold cranking amps from the larger battery are helpful for winter starting.

awizarddresden · Post by **awizarddresden** » 04 Jan 2026, 07:40

I had a similar issue where I would get a hard start if it was the first one of the day. Once it was warmed up everything ran fine. I replaced the fuel pump and nothing changed. It ended up being my CBV a little gasket in the turbo housing was leaking air past the MAF sensor and throwing the system out of wack. It's worth a check to do a smoke test on your vacuum lines.

SailorSteve22 · Post by **SailorSteve22** » 12 Jan 2026, 07:41

Fuel pumps rarely need changing on these cars. I have a electronic control module on top of the tank which cost about $20 and is really easy replacement. Sounds like you might have a bad coil or spark plugs also. These tend to surface in colder weather