Powertrain jolting at highway speeds

[Supercharged111]

Have you already done the obvious plugs, wires, cap, rotor?

 

[c1500deathtrap]

sounds like a converter lockup issue to me.

 

[Schurkey]

sounds like a converter lockup issue to me.

Just SCREAMS TCC to me.

 

[Liam Oswald]

Have you already done the obvious plugs, wires, cap, rotor?

I have put new plugs in last year since the ones that were in there were very old, it’s got a junk yard distributor in it right now and i have a feeling it’s not very good the only way I was able to get the timing correct on the scanner was to turn it clockwise to the point where it was very close to the upper intake and just enough room to slip the spark plug wire boot on where it’s closest to plastic intake so probably going to try a different distributor to see what happens...like I said earlier I have a p3040 code I cannot seem to get rid of.

Like mentioned above..Wondering if this solenoid has failed within the transmission even though there’s no codes for it appearing. Not sure how difficult it is to change / test

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[Supercharged111]

There are TCC PWM delete kits out there that fix it, generally don't need the solenoid. If it is the TCC it will feel like rumble strips and not a jerk.

 

[Sparkyenfuego13]

I have a 1998 Cheyenne with 5.7 vortec, and had I think the same issues, stuttering at highway speeds, couldn't figure it out. Did all the same replacements, pump, filter, pressure reg, spider,.. finally replaced the CAM POSITION SENSOR on the distributor, and problem solved. She runs like a champ now.

 

[Supercharged111]

I have a 1998 Cheyenne with 5.7 vortec, and had I think the same issues, stuttering at highway speeds, couldn't figure it out. Did all the same replacements, pump, filter, pressure reg, spider,.. finally replaced the CAM POSITION SENSOR on the distributor, and problem solved. She runs like a champ now.

Did you have any codes?

 

[Sparkyenfuego13]

It was very random. I believe it was the same code, but I dont remember. I could tell when the truck CEL was going to come on. It would start to run rough, then the light would come on. I would check the code, and after a few days, it would just turn off. Drove me crazy trying to find it. Code said it was a random misfire, I think P0300. Did the cap, rotor, and plugs a couple times trying to narrow it down. But no luck. Read, and read lots of different diagnostic forums, and trouble shooting sights, as I had even taken it to a few different mechanics, with sophisticated high tech equipment to read the code, and pin it down to something specific, again no luck. The last couple items I had it narrowed down to, was the ECM, or the entire distributor unit. I found a site that had a few guys having very similar issues and only replaced the CAM POSITION SENSOR, and had success. I thought, I'd try that, before putting in a complete distributor as I believe the sensor was only $30. Have been running trouble free since, and it's been about 2 years.

 

[Liam Oswald]

This big Issue turned out to be the distributor, also found that one of the wires for the cam position sensor got pinched at some point.Running much better now with no misfires but still can’t achieve +2* to -2* camshaft retard degrees with the scanner it seems to still be defaulting to -45* no matter what I do. Not sure what else could cause this other than a worn out timing chain.. thanks for the help guys really appreciate it

 

[Supercharged111]

Could need a timing chain.