2003 Jeep Grand Cherokee Getting codes P0351 P0353

Cylinders 1 and 3 are the problem. Check them to make sure they are getting good spark to the plugs. If they are, check compression. The popping you hear from the intake has me a bit concerned. If all checks out, focus on the fuel injectors for those cylinders. Make sure they are getting power and putting fuel into the system. They could simply be plugged.

So.... I had codes P0340 - P1391 and P0320....... Changed Crank position sensor and Cam position sensor..... The only problem I had before this was sometimes my 2002 Grand Cherokee Laredo 4.0 wouldn't start..... NOW after changing both sensors it ran great for about 45 minutes..... Shut it down and came out about an hour later and started right up..... after about 2 minutes it started running rough.... check engine light is on and will stall out when trying to accelerate... Hmmmmmmm..... NOW I get codes P0351-P0352-P0353 and P1391........ Keep in mind that I had no problems with the running condition before this except the on and off starting problem....., Any Ideas?? My wife is getting frustrated with me....

Hey BIG D 62,

This sounds like you may have a broken valve spring on an intake valve on either cylinder 1 or 3.

Please remove the valve cover and inspect

Please let us know happens so it will help others.

Best, Ken.