I was having hard start symptoms and some sputtering. One person said maybe fuel filter, people on here said probably Fuel pressure regulator, and I got a check engine for the P301, 302, 304, I believe, which are spark plugs and/or coils.

I recently replaced the 302/304 set, so I have a hard time believing that is an issue. I have owned the car for 10 years and maybe 118,000 miles? I have replaced all 301-304 once before

Then the symptoms stopped. I left car with garage and they checked the regulator for a leak and the spark plugs. Everything seems fine. Running smooth.

I wonder if I was buying inferior gas? I do know that once before when I bought costco gas I had some of those problems. I thought I was buying only national brand gas but maybe I didn't once recently. Cannot remember. Does anyone know why gas quality could affect my car but my friend's Ford is okay with any gas?

 

Yes it can but I doubt that is the issue.

 

studies have shown there's very little benefit to buying brand gas versus buying at a wholesaler since they actually buy from the same refineries. Its possible you could have had some water in your gas - but I doubt its specific to Costco vs buying at a brand station. Personally I tend to not buy gas at a station when the truck is filling the tank (stirring up the station's tanks) - but I have no research to say if that's a real concern since I know station pumps have filters too. I would look at other variable conditions - was it wet or rainy when your car was having issues? warm or cold? Did you do a series of short drives? I'd be more suspicious of old spark plug wires, worn rotor/cap, fuel pump relays, etc.

 

Water in the gas. Happens in the winter. They make a chemical additive that you add to the fuel. Works like a charm. Not the Brand. All underground tanks are susceptible.

 

Thanks for the comments. That video was great. I watched the whole thing and took notes.

I did have multi misfire, but not with the general Misfire number P0300 that the video suggested would happen in that case. I also didn't have any other code, like one for the Mass Air Sensor (is that the name?), which was suggested would show up if that was the problem causing the multi misfire. The garage said the fuel pressure is fine and the spark plugs are fine. I replaced 302 and 304 recently (bad judge of time-1 to 2 years, or less, forgot what garage told me).

The hard start was happening for a couple of months and it was cold out. (It could have been one tank of gas for that whole time period, but maybe two.) One day I had some sputtering/like jerky driving and not really going anywhere, just a few feet, then it was okay, with the car after I started it after being in a store for about 30 minutes, and it happened to be unseasonally warm that day 60-70 degrees. Then, the symptoms just stopped, and I had gotten more gas at a brand place for sure, whether that is related or not.

As an aside, because the vid mentioned head gaskets from over heating, I did have an issue of the antifreeze shooting out and steaming two summers ago. I had the car towed to the garage and got a new part, that part failed in October and it was replaced under warranty. I don't remember what that part was.

Anyway, like I said the car is running well now with no codes. So I guess I just wait to see if the codes come back, if they do not, I guess I had purchased gas with water in it, like the other commentators suggested?

Is this how I should be looking at this issue? Thanks!

 

OH! Are you saying that water seeps through the underground tanks in the winter and can happen at any station, regardless of brand name or cheapie gas? The tanks are not metal?

 

 

it is possible for underground tanks to leak - most stations are inspected for that but once in a while you'll see a gas station getting torn up to get its tanks replaced. That's not the general concern. Mostly water can get in through condensation over time. So if you throw in one bottle of "Heat" (aka isopropyl alcohol which from Chemistry class explains how polar and non-polar solvents can become miscible) in your gas tank at the start of the winter season you should be good to go. What the alcohol does is it allows the water to dissolve into the gasoline and over the next tank full or so you just burn it off. Best way is to start with an almost empty tank, throw one bottle in, fill the tank and the small amounts of water (which is enough to settle and freeze in a fuel line) will be mixed in with 10-15 gallons of gas so you'd never notice it. However, without the alcohol, you get what the RSPI video shows... a frothy mix that eventually settles back out with water on the bottom (as it has the heavier specific gravity... sorry more chemistry class stuff).

 

I went to NAPA and got a bottle of something like this, and it did the trick. Thanks everyone.

 

So the symptoms were when it was over 70 degrees my car would sputter/stop driving when trying to leave a parking space after I had been running errands and was at the 3rd or 4th stop.

The car wanted spark plus and coils replaced, oxygen sensor replaced, etc. none of that worked. What did work was buying PREMIUM GAS. I was buying 87 octane and need 91 octane. I was told gas BRAND didn't matter, because I was buying only national named brands. But I was thinking quality/octane didn't matter. Once I started buying premium gas, it was fine.

Buy Premium, people.

 

Not likely related to octane and not typical to Volvos. Perhaps your car's knock sensors are not working. Octane rating predicts the fuel's ability to resist ignition by compression. modern engines retard the timing or alter the mixture to do the same based on feedback from the knock sensors. Besides, the only time a car tends to ping (aka knock) where octane makes a difference is during hard acceleration - certainly not while backing out of a parking spot.

 

Now that we are in summer, I will have plenty of opportunity to make sure that this issue is fixed. If the symptom does come back, I will update.

 

Yep. This problem was finally solved by using premium gas exclusively. FYI