1996 Buick Regal Repair Question
Mileage: 139,000 miles.
Buick Regal Engine Problem
Asked by goosenec70Answer
Try swapping the injector 3 and see if the misfire moves-P0300 can also be caused by a vacuum leak or bad fuel
http://www.2carpros.com/articles/engine-misfires-or-runs-rough
I forgot to add that all injectors were changed at the time of the post. I have tried checking for vacuum leaks, but not with a smoke machine. I took it to the shop that I used to go to ( before I worked on my own cars), I told the guy everything I did...he didn't want to take it for a diagnostic. Back to the drawing board. Thanks for your reply!
You don't need a smoke machine use a vacuum gauge this gauge tells you a lot about the engine and also is the fuel pressure within specs?
I checked the fuel pressure Friday, it was 38 psi. I took the vacuum hose off the for,hit the throttle, it jumped passed 45 to 50 I think. But I've tried leaving the hose off to see if gas comes out. 10 to 15 mins, no gas. I got a hard start,then cut off on Friday. It started, but was stumbling real bad. I got a blinking ses light,then it held. I got home to check the light, which was a p0300. This was after driving 80 miles on the freeway. Some guy told me that the crankshaft sensor or camshaft sensor may be acting up. Said it was where my hard starts we're probably coming from. I hope this info helps
Sounds like you either have a leaky injector/s or the fuel pump is weak-it has to be on 41-47psi when you turn key on-also you need to check the engine compression, sparkplugs and injectors-also the cam and crank sensor-
http://www.obd-codes.com/p0300
It's been some months now. I took it to another shop. They ran a dyno...told me the pressure was low(which I already knew) they told me they couldn't go any further until that problem was fixed. I changed it , but no difference.I performed a vacuum test...the needle was bouncing at 12. The book said this could be from a worn or broken valve spring. What do you think?