Starting Issues

[Andys_Volvo]

5-8-17

Hello again,

I am back with a new post for a different car. It is a 98 S70 GLT with 313,000 miles on it. This car has had only minimal use in the last two years and has been parked outside. I did start and run it every two to three weeks or take it on short errands. In the year or so before I parked it I replaced the rotor, cap, wires and plugs as well as the fuel pressure regulator. While it was parked I did re-fill the tank with premium gas when necessary but with much less frequency. Due to the need to repair my new daily driver I have been driving the 98 regularly for about a week or so. I did need to replace the battery and evict a four legged tenant but once I did that the car started and ran without difficulty. After driving for a few days it was not as quick to start as it usually was, cranking for just a couple seconds before starting. Not a lot of hesitation but noticeable. It has gotten just a bit worse to the point that it will crank and sputter upon the initial attempt to start it. However, upon turning the key off and attempting again right away it will start immediately and then run fine without any hesitation, stalling or loss in power. It does not happen all the time and is NOT limited to just when the car has been sitting for an extended time. On at least one occasion it even sputtered when attempting to start it immediately after shutting it down. This too is irregular as most of the time it will start right up after only being stopped for a short period. Also there was still good pressure at the rail after it was sitting for an hour or so. I will check the pressure after it has been sitting overnight to see if there is any difference as I suspect maybe a bad check valve in the pump. I don't think it is a relay as I can hear the fuel pump running when I turn the key partially. The fuel pump is not the original. I replaced it a few years ago but did so with a cheap version. I am thinking that maybe the fuel is contaminated and/or the fuel filter is junked up. Any suggestions would be most appreciated.
Thank you.

5-9-17

Checked pressure at the rail this morning and there was no pressure after sitting all night. Ran the pump a couple times, started and ran fine. Drove it and parked for an hour and a half then started no problem. Twice later it this morning after only shutting it off for a few minutes it stumbled on the first attempt to start but started up right away with the second attempt, immediately after the first.
By the way. There are no codes.

Any help and suggestions will be appreciated.

Thank you.

[Clemens]

A few things come to mind:
When it is having a hard time starting, can you smell unburnt gas? If so, check the condition of the plugs. They might have corroded even though you took care of it while it was sitting.
Fuel pump from my experience either works or doesn't.
Fuel filter clogged: unlikely
Battery is new so it should work unless the alternator is bad and the battery/charging system light is burnt out
It could be a corroded ground.
Do you have an IAC valve? If so, is it working?

[Andys_Volvo]

Thanks for the reply
No gas smell.
No indication of bad alternator
Will check the ground if I can find it and
What is an IAC valve?

[wizechatmgr]

Idle air control valve

[cn90]

Fuel Pump:
- FWD model...Bosch 69693
- AWD: likely Walbro

Fuel Relay, search forum for jumping terminals 15 and 87.

[Andys_Volvo]

Thanks for the replies. One more observation to add. Don't know if it is significant. When the car does start it immediately revs like it got a surge of fuel. I don't remember it doing this before. This is when cold or hot.

Thanks.

[Clemens]

Vacum leak? Would unmetered air do that? I think so

[Andys_Volvo]

Would a vacuum leak cause a drop in fuel pressure at the rail?
I was thinking possibly a leaking fuel injector but don't know if that makes sense.