I have a 99 that has the 4.3 and it is giving me a p0300 engine code which I believe is random or multiple cylinder misfires. I have changed the cap,rotor,wires,plugs, and egr with no change in the engine performance. I put a test gauge on the fuel pressure test port and I was getting a rapid fluctuation between 65 and 75 psi with the engine running. I did see that some guys had problems with distributor gears I guess I can check the distributor next, If someone thinks that might fix the problem. Any insight on this would be great!

Thanks

 

possibly coil? injectors? fuel pressure regulator? could be a lot of things. thats all i can think of right now. try searching p0300 im sure you will find lots of problems/solutions

 

Yeah! That is what I was afraid of, I guess I have to just start changing out more parts it sounds like until I hit the right one that makes the problem go away. Thanks for the heads up!

 

total wrong way to go about it. you will end up spending ton of money you didnt need too. do your research and whatever part you suspect there will almost always be a way to test it and make sure your not pissing money away. search function can be your best friend. good luck

 

The dreaded P0300 CAUTION LONG POST

P030x Explained (x=0,1,2,3,4,5,6)

There is sooooo much information on this site, using the 'search' function makes things so much easier.

 

Alright some trouble shooting info. Thanks for the attachments!!! I will let you guys know what I find. Thanks again