Hi.. i did a oil change (10w-30, its what the oil cap says) last week and drove home, but after that did not use the car for a week. So yesterday when I try to start it, it didn't (not cranking properly). It should be the battery because it is freezing out side. So I jumped the car and my friend accidentally cross the connections. But didn't crank bcoz there where no response from the car (even when I try to crank it). Then I realized it crossed and fixed it and used proper connections. However, at that time the car wont start. It crank normally but not firing, it sounds like it try'* and I can hear POP sound (like a blow by ignition, but not ignition or firing a cylinder). But does not start.

Then I charge the battery and tried it again. Same result.So i tryed for couple of time and left it.

When I try to start it today (after 24hrs) The battery is not enough (it shows 10V). But doesn't crank. However the battery is not drain totally (So I'm assuming the cross connection did not do any damage). So I'm charging the battery now.

It has 208,296 Miles and the oil pressure is normal when I crank.

Q1 ) is it possible that because of the oil change and excessive wear there is not enough compression to start?

Q2) is something fried due to the cross connection jump start. ( But did not crank during the cross connection time, just put the key in to ignition) No engine light or any signs of waring or smoke came out from the engine during the cross connection.

Thanks guys.

Good chance you killed the battery, one dead cell, each cell is 2v. I would start by disconnecting the battery for about a half hour to ensure a reset of the PCM, then try again.

Year and make also helps us.

Thank you.. itz 92 Pontiac Bonneville.

Now I am charging the battery. Can the PCM get effected or fried?

Thanks

I guess it'* possible, but I've never seen anyone jump backwards. I would suggest testing voltage on the battery again. If it'* still showing 10v then it'* fried.

If anything you might have blown some fuses or relays

Thanks guys for the help..

I am happy to say, car is starting now. I charge the battery and left it in the maintain mode for couple of hrs. Then when I connected it to the car it showed 12+ v. Then it did not start as well, check the spark plugs and it was ok, then check the fuel pressure and it was normal. So finally I used some starter fluid and cranked the car (cranked for like good 20sec with out stopping, bit worried about the starter..but :dontknow: )

then it started and stall for a while. Did the same thing after like 20 sec. whallaaa....it worked.

Oil pressure was normal and it shoes 14v while in 1000+ rpm. So assume it did not effect the battery. (cross my fingers)

Drove around for a while and left it for like good 2hr (itz freezing in Minnesota). Yep it started completely normal after that

Ones again, thanks guys..