Well it fixed the check engine light but now runs like crap

[Zeronight001]

1997 Chevy K 1500 5.7 l had check engine light issues for crank position and camshaft position sensor. I love how it always puts those both together and not separate. I replaced them both one at a time and after replacing the camshaft position sensor the check engine light has not returned since but it runs like crap it'll sit in idle great but when you very lightly hold the speed it feels like it's misfiring and stumbling all over the place. And this happens pretty much at any speed I haven't had any power issues and I can't find anything left disconnected the plugs are new the wires are good the distributor cap is fine I cleaned off all the posts. at this point i wish the check engine light Would throw a code. Any ideas would be helpful thanks

 

[Drunkcanuk]

1997 Chevy K 1500 5.7 l had check engine light issues for crank position and camshaft position sensor. I love how it always puts those both together and not separate. I replaced them both one at a time and after replacing the camshaft position sensor the check engine light has not returned since but it runs like crap it'll sit in idle great but when you very lightly hold the speed it feels like it's misfiring and stumbling all over the place. And this happens pretty much at any speed I haven't had any power issues and I can't find anything left disconnected the plugs are new the wires are good the distributor cap is fine I cleaned off all the posts. at this point i wish the check engine light Would throw a code. Any ideas would be helpful thanks

I'm not a vortec guy, but I think there is some kind of ECU re-learn involved with changing the crankshaft position sensor.
Again.... could be pulling that out of my a$$, but it sounds familiar.
Hopefully someone will be along shortly with the correct answer!

 

[Supercharged111]

No, there is a relearn that should be performed when the CKP sensor or PCM is changed out. It's the Crank Angle Sensor Error (CASE) relearn. You'll need some sort of bidirectional controller to perform it, so someone with a decent scanner or tuning software.

 

[Drunkcanuk]

No, there is a relearn that should be performed when the CKP sensor or PCM is changed out. It's the Crank Angle Sensor Error (CASE) relearn. You'll need some sort of bidirectional controller to perform it, so someone with a decent scanner or tuning software.

I knew it was one of them! Lol

 

[movietvet]

I could be wrong, been a long time, but I think if you have enough cycles and driving, it resets itself, eventually?

 

[Schurkey]

WHAT CODE(s) did you get that led you to crank and cam sensors?

Kinda guessing it was the code for cam/crank sensor correlation, which by it's nature has to include both sensors.

In which case, you should be adjusting the distributor to synch the sensors, not replacing the sensors.

 

[movietvet]

WHAT CODE(s) did you get that led you to crank and cam sensors?

Kinda guessing it was the code for cam/crank sensor correlation, which by it's nature has to include both sensors.

In which case, you should be adjusting the distributor to synch the sensors, not replacing the sensors.

But, if he really did not need to replace the sensors and all he really should have done was adjust the distributor to synch the sensors, would not the CEL be on again/still?

Or, just by replacing the sensors he has created a whole other scenario of CEL maybe or maybe not?

 

[Zeronight001]

P1345 I think was the code I have it written down somewhere but I first replaced the crankshaft position sensor and everything was fine for a few days no issues no codes then it threw another code of the same so I replaced the camshaft position sensor it wasn't until after I changed that that I've been having the issues and I have yet to get another code. From everything I've seen and felt driving it it feels more like a throttle position sensor issue now which is possible but I was hoping that I just forgotten adjustment or something

 

[Supercharged111]

P1345 I think was the code I have it written down somewhere but I first replaced the crankshaft position sensor and everything was fine for a few days no issues no codes then it threw another code of the same so I replaced the camshaft position sensor it wasn't until after I changed that that I've been having the issues and I have yet to get another code. From everything I've seen and felt driving it it feels more like a throttle position sensor issue now which is possible but I was hoping that I just forgotten adjustment or something

So Schurkey was right. All you needed to do was set your CMPRET. But now that you've opened up Pandora's Box you need to do a crank relearn in addition to that CMPRET. The latter can be a accomplished with a Bluetooth dealie and a cell phone app while the former needs a bidirectional tool. The fact that changing the cam sensor made things worse has me very suspicious that a plug wire is no longer seated and/or there's an issue with the cap and rotor unless those were replaced. You can try driving with the cam sensor unplugged, truck won't mind at all. But if that magically cleans it up then I'd suspect a garbage sensor via the parts cannon.

 

[Zeronight001]

So I disconnected the camshaft position sensor and the truck ran like crap even worse than before. So then I reconnected and it started running better around town but still with the issue when I'm just cruising light throttle. So I don't believe it's the sensor I think there's something else wrong that didn't come up until now what that could be I have no idea it even pops and misses when it shifts gears which I think is weird and have not seen much before