My car is been running fine and decided to change the oil and filter. I replaced it with Mobil 5w-30. Once im done, the car will not start. It will crank but not start. I didnot touch anything except for the filter and change the oil. Please advise...thank you

 

My first thought is always to pull the wire going from the coil to the distributor and place it in such a way that you can reach in, turn the engine over, and see if it will fire to ground. If you have fire to ground from the coil, it isn't ignition related. If you have that, pull a wire from a plug, insert a phillips screwdriver in the wire, and lay the screwdriver so that when you turn the engine over, you can see that spark is getting to the plug. That isolates the possibility of a bad rotor button. With this all being good, it about has to be fuel related. Fuel pressure, fuel pump, etc. Send me you number if you need to discuss, Gene.

 

Several possible angles of approach. I'd begin by checking for spark. Post back if you need help with that.

Aside: Why 5/30 oil? Most owners use a heavier oil in a V12, and I'm assuming that's what you have. Like 10/40 or 20/50

Cheers
DD

 

ooppss.. i used 10/40... . BTW hows changing the oil affect the spark ? It doesnot make sense....

 

It wouldn't, and I agree, it doesn't !

Cheers
DD

 

Absolutely. It sounds like you've been bitten by the "prince of darkness"

 

Jolted a connection loose when on and off the jack's possibly when doing your filter possibly, but you would be damn unlucky tbh.

 

i would guess the issues has nothing to do with changing the oil either a fluke that a part failed at the same time or possibly bumped a wire off of something.

start with the basics

 

btw, i check my fuel psi and psi after the regulator. when i put my ignition in#1, the fuel psi regulator show a psi of 40, then will fluctuate once i try to start the car. is that normal ?

 

thanks for all the help..so far this will be the step that i will do

1. chk fuel psi
2. chk regulator psi...should be what psi ?
3. chk if icoil has a spark. how will i take reading on the coil ? what should be the reading ?
4. chk if i have a spark to the spark plug ?
5. whats next if everything works and doesnot start ?

thank you for all the help

 

Perhaps you could start by looking at the inertia switch. Press it to ensure that it is reset.

Can you hear the fuel pump working? It's easy to pop out the fuel pump relay and jump it to force the pump to operate. It's a lot easier than trying to hook up a fuel press gauge

 

It is normal for the fuel pressure to mildly fluctuate. However, I always insure I have fire before anything else. A gasoline engine can be started with ether, or "starting fluid" if it has fire, but no amount of fuel will start the car if it isn't getting fire to the plugs. It only takes three basic things to run: fire, fuel, and air. Get those three, and it about has to start.

 

I always was taught Fuel, spark and compression. No compression = no start

 

Yep if you have Air, Fuel and Spark, should work no reason why it shouldn't.
personally I think you have simply knocked a wire out of place, another thought, have you checked your fuses? Did you spill oil while filling it up, just trying to think is there any critical wiring near the oil filler cap that could have being dowsed in oil and create a point of no contact?
Good luck

 

where is the inertia switch located ? I have a brand new pump, i get about 75-80 psi outlest and get about 40 psi after the pressure regulator. Another question, does low auto transmission affect the starting ? Just curious . Because i changed the transmission oil too while waiting for my new fuel pump to come...just thinking....thank you all

 

The inertia switch should be just forward of the door opening, under the end of the dashboard. Sorta square-ish; black plastic. Damned if I can remember which side of the car, though ! It'll either be on the left side or on the right side. One of the two

No relationship between no-start and low trans fluid

Cheers
DD

 

i saw it...thanks doug

 

I didn't mention compression at all, because the car was running prior to the oil change. I don't know any body else' plan of attack, but stick to what my grandfather taught me growing up. He worked on neighbors mowers, tillers, cars, boats, always something to work on. But what always stuck with me was he ALWAYS checked the fire first. If he had fire, he would shoot a shot of ether in it, and see if he could get it to try to start. If it did, he went looking for a fuel delivery problem. I bought my current XJS as a non-running Marelli car. Using the same process, I got it running. It had fire on both banks for about 3 seconds, then the B bank would drop out. Never worked on, and never even had looked at the makings of a Marelli ignition. Got TONS of advice on fuel. But I knew, that until I had constant spark on both banks, what difference did it make it if I got fuel? Once I had fire on both banks, it fired right up.

 

just chk my coil. I have a spark on it. Next thing is the spark plug. Thanks

 

...Hello All...i got my car started today...i followed your advice, chk the fire triangle ...and then check all the wire. I noticed that one of the wire is cut. this wire is going to the thermostat control sensor. As soon as I fixed this(wrap an electrical tape around it)...the car starts...does it make any sense? I will check all my wiring tomorrow to make sure that nothing is cut or expose. Thank you all for the advice. I will post another thread to ask for your advice, now that the car is starting. I will fill up the transmission oil tomorrow and go from there.