New here, purchased my first Volvo a couple weeks ago.. I got a 2004 S40 turbo with 86k miles on it. I am having trouble getting the car to start, but once it’s started and warmed up, don’t have any issues with it running/idle/etc. Here’s the info I know -

• I got it with a 1/4 tank of gas. It gave me an issue starting once or twice, where it just took two tries to start up.
• I have the carfax and it has had routine maintenance. Filters were changed 10k miles ago, (at 75k miles in 2017). Timing belt and serpentine belt were also changed at that time.
• brought it into the shop for an oil change, and preventative maintenance, they gave it a clean bill of health. They did say there was a small leak somewhere, but they couldn’t tell from where. And told me I could go back in a couple weeks to see if they could identify the leak.
• We filled up the tank with regular grade gas, added sea foam, and added Lucas engine oil stop leak.
• May have started normal a couple times after all of this, but every time I start it now, it takes 2 tries to get it started. I turn the key and let it try to crank. Turn it back, turn the key to crank and give it a little gas and it starts up.
• I brought it back to the same shop and of course the 10 times he started it, the car cranked right up. I assume it’s because everything was still warm.
• no check engine lights on

Is it because I’m running regular and not the recommended premium? What else could it be? The guy at the shop told me he couldn’t really diagnose the problem if the car is starting right up 🙃

also wanted to add that one time when I started it up, I put her in Drive and went to press the brakes, and it felt like the brakes were not working AT ALL (scary). But then once she was warmed up, everything was fine. Maybe I need to let her warm up once I start it before I get going?

 

two possible causes I'd check out first:

1) engine coolant temp sensor - does the temp gauge wander or start off reading warm? To test, you'll find the sensor under the thermonstat dome where the upper hose goes into the head. Unplug the connector and measure the resistance. Should read ~3K ohms (maybe 2500 if its warm out). If its much lower - say under 1000 ohms, the ECU thinks the engine is warm and won't enrich the fuel at start up
2) Fuel pressure regulator (assume you have a gen 1 S40). Its a small device bolted into the fuel rail on the side away from the timing belt. There's an S shaped vacuum line. After a few cranks, pull the vacuum hose off and see if any fuel leaks out. If so you have a torn diaphram and need to replace the regulator. What can happen is your fuel rail pressure bleeds off through the regulator and you need extra cranks to build up fuel pressure at the rail. Altnernatively you can throw a fuel pressure guage on the schrader valve on the end of the rail. WIth the engine cold (ie first start) there should be some residual pressure (say 25 PSI or more,,)

After that, I'd check plugs and inspect the wire harness to the coils for cracked connector that could lead to a cold spark. You can also scan for any stored CEL codes.