I know this is a Blazer forum but this is a 2000 GMC Jimmy but has the 4.3L vortex I also have a 2003 Blazer that runs perfect but I am having problems with my Jimmy and any suggestion would be greatly apperciated oh by the way I am a new member as of today. History of vehicle,I bought my son a 1997 GMC Jimmy after he got his license he hit a tree and bent the frame. A friend of his had a 2000 Jimmy for sale with a missing rod out the side of the motor so I bought that vehicle to put the 97 motor in, Went through the motor completely cleaned and painted everything, put motor in,put disturber in first key turn started and ran perfectly.Test drove and he drove it home 1.5 hrs away. Got a phone call saying the check engine light was on and it flashed a few times. Changed Coil,EGR valve,MAF sensor,new plugs,wires,distributor,rotor,17inches of vaccum,did a crankshaft relearn twice and still running bad,Fuel PSI is at 55 to 60 psi, Idles perfect but as soon as you hit the throttle it starts misfiring. I have been to a couple of sites and they were talking about putting a paper clip under the crankshaft position sensor has anybody ever heard or dont this?

 

Welcome to the forum. I fought with this exact problem for two weeks and finally got it figured out about a week ago. In my case, it was a bad distributor cap from the parts store. Brand new but bad. Replaced it with another one (not another bad one, LOL) and it's been running perfect ever since. That's my story. Hope it helps.

 

Tomorrow I am going to change the camshaft position sensor and since I am doing that I am going to put a new cap and rotor on it.

 

*Moved to 2nd Gen Tech* - Forum Help & Suggestions Center is for forum related problems, not vehicle related problems. Please review the description of each forum section and choose the one that best suits your question.

As far as your problem goes... P030x - Random/Multiple Cylinder Misfire Detected

Diagnose, don't take the shotgun approach.

 

Sorry I was in the wrong spot but I am new. I had all the parts on hand from the motors I changed so that was my first approach. My son had the vehicle I just got it back the other day. You have to have access to some technical stuff to began diagnosis and it is not readily available yet. I just though I would ask for some suggestion,maybe somebody has the same problem as me.

 

Is that a new type of engine ? You have a what,,,, 4.3L vortex ? Or is it a 4.3L vortec ? That P030x is a mean code to narrow down. Kyle gave you some good info to read up on. Good Luck T.J.

 

Thanks for correcting my spelling and being no help at all. Thrust me I know the P0300 is a nightmare and if you can not offer any help please keep your sarcastic remarks to yourself. THANKS for nothing

 

Nothing to do with your spelling, Sarcastic remark, Hummmmm, I try my best to help others members on here, Just becareful as to what you say . Your comments may just run others off. Also saying I am new,,,, Sorry,,, does not cut it on the forum. RULES. Good luck. T.J.

 

Excuse me for being a new member and polite.

 

Everybody step back and take a deep breath.