I have a grand Vitara aswell sometimes mine does the same thing all I do is turn the key on let the fuel pump work until it stops then a crank it and it starts first goAt times my grand vitara takes about 5-6 seconds to crank over and start. Other times it starts up right away. I can’t pin it down.
Here’s what I’ve done so far(not in any particular order):
1. Checked cylinder pressures when cold, passenger side is 145 PSI all across, driver side is 150PSI all across.
2. Replaced spark plugs.
3. Had all 6 injectors serviced and cleaned, they’re at factory spec again.
4. Replaced fuel pressure regulator with a Delphi one.
5. Installed an amazon special check valve right before the fuel filter.
6. I checked IAC valve, comes back at factory spec.
7. Replaced fuel filter.
I ordered a Delphi fuel pump, maybe my stock 20 year old fuel pump is on its way out. Plan is to replace it this weekend.
When idling the fuel pressure is 35PSI, when I key on the fuel pressure is 40PSI. I keep checking the feed line fuel pressure with a harbor freight pressure gauge. When I block off the feed line, return line and the vacuum line it still drops in fuel pressure about 5 PSI in 15 minutes. I’m not sure how that’s possible since the injectors came back at factory spec. If I don’t block off any fuel lines, the pressure actually rises, from 34PSI to 39PSI in 5 minutes, 15 minutes it started dropping slowly, after 45 minutes I was down to 10 PSI.
Any advice would be appreciated.