I just got the truck 6 months or so ago. It has been in serious need of a tune up since I got it. It has been missing a little since I got it, but it ran okay. Then I was heading out one morning and suddenly it started running really rough!!! So rough I barely got it home! It acts like it's out of time, or not hitting on all cylinders. I replaced the plugs and wires (which definitely needed to be done) The plugs looked rough. It helped a little but was still missing bad. I then replaced both coils after receiving multiple "misfire" codes on several cylinders (like 5 of them) on both sides of engine. (the thing has 2 coils) I then replaced both coils. It is running better, I can at least keep it running now, but it's still missing bad like it's out of time. If it were a 1985 I'd twist the distributor and that would be that. But it's NOT! And I don't know a lot about what controls the ignition timing. I have not got the code reader at this time so I have not been able to check them again since replacing the plugs, wires, and both coils. From what I've seen I'm thinking the camshaft position sensor needs to be replaced, but I don't KNOW this and need some help. It idles fairly smoothly but hesitates and stalls as you accelerate and has no power. The exhaust is telling me that it's not using the fuel, it's instead coming out the tailpipe. It just seems to be "out of time". When you drop it into gear it almost stalls out and really hesitates on take off. No power whatsoever. Any help would be appreciated

 

It's probably your timing that is off. I would get that checked.

 

Might be dirty injectors. Do a compression test. If it's been misfiring for any length of time, the cats are probably plugged.

Ignition timing is 100% computer controlled.

 

The timing is definately off!!! But the timing is controlled by a camshaft position sensor (you cannot just put a timing light on it) My question is "Am I on the right track replacing the camshaft position sensor?" Because there is also a crankshaft position sensor and a couple other things that control the timing including the drivetrain control computer (or something like that) If the thing had a distributor it'd be fixed!!! The injectors seem to be working fine because the exhaust is fuel rich. But even the injector timing is controlled by the CPS and also the computer.

 

The timing chain hasn't slipped too much or it would of banged the valves. The 4.6 is an interference engine. If a timing chain jumps time you can't just turn the dist. and fix it because that also effects valve timing. Good luck with it Texas.

 

I realize the timing is controlled by the computer GLC, But from what I've been told the camshaft postion sensor sends the signal to the computer, and a faulty CPS will cause all the symptoms I have described. (since the computer gets it's info from the sensor) From what I've read it HAS to be either a vacuum issue (which I don't think it is because I've checked) Or the crankshaft position sensor, the camshaft position sensor, or the drivetrain computer itself from what I've read. Each causes slightly different symptoms. Reading what I have my symptoms match most closely to it being the camshaft position sensor. It idles good until you drop it into gear or put a load on it. And it's not burning all of the fuel.... it ends up going out the tailpipe. It hesitates when I step on the gas for a moment, then it takes off but it misses (like any vehicle does when the timing is not correct) The plugs, plug wires, and spark plugs have all been changed (and gapped / changed correctly) I'm certain it's not those. I don't have much money or many tools to do a ton of testing or take it somewhere (or it'd be fixed already) I cannot do a compression test here. But I borrowed a code reader and got the code for O2 sensor needing replaced, and 5 seperate codes for misfire (BEFORE I replaced the plugs, wires, and the 2 ignition coils) It runs much stronger now, but the timing is definitely off still. Am I wrong

 

When talking about codes, please post the exact "P" codes, not the interpretation. There is no code that says "the O2 sensor needs to be replaced".

You should be able to borrow a compression gauge from a parts store. No point in chasing sensor issues if there are no codes for them and compression is bad. You need to rule out bad compression and rule out plugged cats.

 

Absolutely get the codes checked again. Your are flying blind without doing that first.