miss, lean codes, and detonation Please Help!!
Well my whole mess started about a year and a half ago so I have quite the story to unwind and it finally has hit a wall and I cannot drive the truck anymore but maybe at least this will finally cause me to be able to fix it. So here goes:
The last things I did to my truck before this started was replace the coil pack with a screamin demon and have the upper intake cleaned at a valvoline oil change station where they ran their version of seafoam through my vacuum lines at the brake booster.
My truck first started with every couple of weeks I would push in the clutch and the idle would run itself up to 3000 rpm's for 2-3 seconds and then drop back down. It was rare but I wanted to get it fixed so after reading up on here I went ahead and replaced the plugs, IAC, TPS, cleaned the throttle body and cleaned my air filter (K&N). That didn't work so after going through a few more IAC's because I figured maybe one was bad I took it to a dealership. The dealership said since there were no codes they couldn't do anything but search for vacuum leaks. None were found. But they suggested that maybe my MAF was bad since I had a K&N. So took it home replaced the MAF. Nothing and by now the problem had persisted to at least 2 or more times everytime I drove it.
So with no hope in sight I just kept on driving it until it came with codes then it started to pop up p0171 and p0174. Excellent both banks running lean so everyone said vacuum leaks. I have checked myself and had 3 other people check for leaks and no one has found any. Well just for fun I went and replaced the cam synchro and no change again.
So still nothing seemingly coming to be I kept on driving it I had a friend at work give me a program to run a constant view of what the computer was reading which showed all o2 sensors reading fine and adjusting correctly and the engine at full load was running about 14% lean which is not to horrendous and expected because of the air filter. I had the PCV replaced and checked the fuel pressure sitting right within specs. Bit the bullet and replaced the intake gasket and head gaskets. Still nothing except now my idle started to go bad as well. It will just bounce between 800 and 1500 rpm's up and down. Sometimes as well when i would push in the clutch no matter what gear or speed I was going it would stall. I watched it as it stalled from the computer readouts too and they just went to 0. I still had electricity but the engine just shut itself down.
Still no idea took it to a buddy's and there was oil in the intake, checked for vacuum leaks with propane and found none so cleaned out the entire intake and put it back together. Then it started to feel like it was having a miss? At WOT and above 3500 rpm's it would start lurching here and there. Not everytime and this still had the bad idle and the rpm's jumping up with the clutched depressed but all of it intermittent. It also started to make an odd rattle sound under the hood at WOT in its open loop I started to think it was pinging taking place but it was quiet to begin with so I just kept driving it. Well last week I went to work and had one of my buddies ride along with me to try and help diagnose the sound since he used to be a tech for dodge and ford years ago. So we are driving up a hill right beside work, WOT so it was running an open loop and 100% load, and out of nowhere it starts being really jerky, bucking the whole way as I accelerated up to 3000 rpm's then all of a sudden detonation began occuring. Very loud and that was definitely what it was. So took my buddy back to work he said take it home and park it. Ran it on a scanner p0316 and p0304 along with the p0171 and p0174 still.
So last ideas that I have are computer or injectors which has to be the timing is completely off so i doubt injectors. So basically computer I am guessing . If you have any other ideas please help me. I have a very well taken care of truck with 77,000 miles on it that is paid off and I can't drive. I'm stuck!