Crank no start has fuel and spark. Everything replaced!!
I suspect the P0300 is only because the crank sensor you replaced needs to be relearned. The PCM has a stored crank sensor electronic waveform. If the current waveform doesn't match the stored one within a certain unknown spec, then it flags a misfire. When you change or disturb the crank sensor, you are supposed to do a crank sensor relearn. P0300 is a random misfire. P0301 - P0306 are misfires flagged on specific cylinders. Again, a crank sensor relearn will not fix a misfire - will only fix a falsely reported misfire. See how that works? But if there really is a felt misfire at 42mph or so, then any misfire should be addressed before a bad waveform is recorded by a crank sensor relearn. Some people will tell you how they didn't have to do it after swapping crank sensors. GM service info says you should. Also be aware that the TCC will not engage when the SES light is on, so if the light comes on and the vibration disappears........
So I ask again, is the engine running rough or is it just the TCC engaging that you are feeling?
Also be aware that transmissions and belt driven accessories can cause false misfires to set even when engine feels smooth. I once was getting P0300 for about 200 miles before my transmission went out.
p.s. the Vident i-link 400 will do a crank sensor relearn.
So do you want to check out the general fuel injection to make sure it is controlling correctly? You have the equipment to do this!!
Last edited by LesMyer; Dec 6, 2023 at 03:30 PM.
Is the vibrating and slight drop in RPM at about 42 mph in OD? If so, that is the Torque Converter Clutch engaging and we need to decide if the engine is actually running rough or not.
I suspect the P0300 is only because the crank sensor you replaced needs to be relearned. The PCM has a stored crank sensor electronic waveform. If the current waveform doesn't match the stored one within a certain unknown spec, then it flags a misfire. When you change or disturb the crank sensor, you are supposed to do a crank sensor relearn. P0300 is a random misfire. P0301 - P0306 are misfires flagged on specific cylinders. Again, a crank sensor relearn will not fix a misfire - will only fix a falsely reported misfire. See how that works? But if there really is a felt misfire at 42mph or so, then any misfire should be addressed before a bad waveform is recorded by a crank sensor relearn. Some people will tell you how they didn't have to do it after swapping crank sensors. GM service info says you should. Also be aware that the TCC will not engage when the SES light is on, so if the light comes on and the vibration disappears........
So I ask again, is the engine running rough or is it just the TCC engaging that you are feeling?
Also be aware that transmissions and belt driven accessories can cause false misfires to set even when engine feels smooth. I once was getting P0300 for about 200 miles before my transmission went out.
p.s. the Vident i-link 400 will do a crank sensor relearn.
So do you want to check out the general fuel injection to make sure it is controlling correctly? You have the equipment to do this!!
I suspect the P0300 is only because the crank sensor you replaced needs to be relearned. The PCM has a stored crank sensor electronic waveform. If the current waveform doesn't match the stored one within a certain unknown spec, then it flags a misfire. When you change or disturb the crank sensor, you are supposed to do a crank sensor relearn. P0300 is a random misfire. P0301 - P0306 are misfires flagged on specific cylinders. Again, a crank sensor relearn will not fix a misfire - will only fix a falsely reported misfire. See how that works? But if there really is a felt misfire at 42mph or so, then any misfire should be addressed before a bad waveform is recorded by a crank sensor relearn. Some people will tell you how they didn't have to do it after swapping crank sensors. GM service info says you should. Also be aware that the TCC will not engage when the SES light is on, so if the light comes on and the vibration disappears........
So I ask again, is the engine running rough or is it just the TCC engaging that you are feeling?
Also be aware that transmissions and belt driven accessories can cause false misfires to set even when engine feels smooth. I once was getting P0300 for about 200 miles before my transmission went out.
p.s. the Vident i-link 400 will do a crank sensor relearn.
So do you want to check out the general fuel injection to make sure it is controlling correctly? You have the equipment to do this!!
I forgot about the leaking brake cylinder. So all the fluid has leaked out and ill need to bleed the brakes down tomorrow. I'll probably go ahead and replace the part while I'm at it. One of the lessons I learned working with you. Don't put problems off. It may ene up costing a whole lot more.
Its running great. I took it out just now and the engine light was on for a couple minutes and went off. Its not vibrating and it idles smooth at the lights. I couldn't ask for more. I can't believe it runs so good. From a pesty p0300 and rough idle at the lights to a crank no start a pile of money time and hopelessness to Blazer Forums and Les and Walleye and finally back on the road with no engine issues. Thank you.
Congrats! Are we done? Just don't believe any subsequent misfire codes unless you can actually feel the misfire. If it runs great, now is the time to do a crank sensor relearn.
Looks like your original problem was probably something with the distributor. But no way of knowing for sure. Good thing (I guess) that you broke the mounting for the cap on the original so we had to replace the distributor.
Are the teeth on the old distributor worn sharp?
Isn't it amazing that the Chinese can make a distributor, ship it to the USA, wholesale it, and a US company can still make money selling it/shipping it for $40? Hard to compete with that.
Looks like your original problem was probably something with the distributor. But no way of knowing for sure. Good thing (I guess) that you broke the mounting for the cap on the original so we had to replace the distributor.
Are the teeth on the old distributor worn sharp?
Isn't it amazing that the Chinese can make a distributor, ship it to the USA, wholesale it, and a US company can still make money selling it/shipping it for $40? Hard to compete with that.
Last edited by LesMyer; Dec 7, 2023 at 01:19 PM.
Well my friend, I got it out on the hwy and opened it up to check out the acceleration. Then it began to hesitate while accelerating unless I came off the throttle and quickly throttled down. At 40 it drove fine. The engine light was blinking. Then on the way back the light was off and it was driving good. So maybe an intermittent issue with fuel maybe?




OOps I see it