Lockup issues?

[Yngwytprik]

So with no cel i never thought to run the codes until tonite. Hooked my scanner up just to see if anything would come up and whatya know. Code for tps popped up. And p1345. Im guessing the p1345 is from when i did the lower i take gasket last week. Its ran great since so i thought everything was good considering theres been no check engine light ‍ (Lockup issue was there long before i did the intake gasket btw). Now im pretty much 99% positive i did the timing correct when i reinstalled the distributor, why would i get that p1345? #1 cylinder tdc on compression stroke, crank lined up with mark, distrubtor slid right in flush with the rotor pointing at #1 cylinder (in the cap) is that what i did wrong there? Is it number one cylinder or number 1 contact in the cap? Either way i beleive the tps could be my lockup issue. Opinions?

 

[1998_K1500_Sub]

Code for tps popped up. I beleive the tps could be my lockup issue. Opinions?

TPS could lead to a lockup issue, as throttle position is used by the ECU as a condition for TPS lock / unlock.

Do you have a scanner which allows you to look at the TPS value while you move the throttle (engine off)?

 

[1998_K1500_Sub]

Im guessing the p1345 is from when i did the lower i take gasket last week. Its ran great since so i thought everything was good considering theres been no check engine light ‍ (Lockup issue was there long before i did the intake gasket btw). Now im pretty much 99% positive i did the timing correct when i reinstalled the distributor, why would i get that p1345? #1 cylinder tdc on compression stroke, crank lined up with mark, distrubtor slid right in flush with the rotor pointing at #1 cylinder (in the cap) is that what i did wrong there?

I had a similar problem when I replaced my lower gaskets. It turned out I had the distributor off just a bit... one tooth maybe or some other "close but not perfect" issue. I seem to remember that I had replaced the distributor and lined up the rotor with #1 on the cap, but I was still off one tooth and the camshaft position sensor (in the distributor) wasn't in the correct position. Something like that.

Clear that code and see if it re-appears.

Here's the relevant section from the service manual.

 

[1998_K1500_Sub]

Here's the manual entry on (re)installing the distributor.

I remember following these instructions when I had the same problem.

 

[Yngwytprik]

Here's the manual entry on (re)installing the distributor.

I remember following these instructions when I had the same problem.

Thank you!

 

[Schurkey]

Reinstalling the distributor via the service-manual procedure gets you close enough that the engine should run.

From there, you adjust the distributor as needed to achieve the 2-degree tolerance at 1100 rpm.

 

[Yngwytprik]

Reinstalling the distributor via the service-manual procedure gets you close enough that the engine should run.

From there, you adjust the distributor as needed to achieve the 2-degree tolerance at 1100 rpm.

I was a tooth off, i was pointing rotor at the number 1 spark plug contact in the cap forgetting there was a “8” that is marked in the distributor where it needed to point. Got that issue fixed and deleted code. Hopefully wont see it again. Ill order a tps sensor and update if that gets rid of the lockup issue or not.

 

[JWOK]

1998 2 door 4x4 tahoe. 5.7 4l60e. 168k. All stock engine and trans. Thing runs great, and 90% of the time drives great as well. But it seem anywhere between 40-50 mph typical cruising throttle its in and out of lockup repeatedly. Any speed over 50 and it stays in lockup just fine. Trans shifts smooth through all the gears and lockup is nice and smooth as well unless im in the 40-50mph range. Then its in and out in and out unless i get goin past 50mph. Any ideas? Oh and figured id add it doesnt feel at all like a jerk or missfire like a tc issue its smooth in lockup and smooth out of lockup over and over.

Read up on TCC regulator/isolator valve issues common to 4l60e. Common symptom is TCC cycling in 45-50 mph range. Repair kits are available for diy if you decide that is the issue.

EDIT: I double posted, sorry.

 

[Yngwytprik]

Sorry takin me a bit, i ordered a oem tps sensor that will be in by friday. And i went ahead and ordered a teckpak tcc upgrade kit since it was under $20. Ill try the tps and see if it fixes issue and either way its getting the tcc valve upgrade since i already purchased. Ill update with results next week or 2.

 

[1998_K1500_Sub]

ordered a teckpak tcc upgrade kit since it was under $20

I was just reading-up on that kit and it seems to be associated with a variety of symptoms (perhaps not all of which might be evident), i.e.,

- hard 1-2 shift at part throttle
- TCC lockup abnormalities
- TCC SLIP CODE P-1870

Do you have other trans symptoms in addition to the lockup "dithering" you mentioned in your initial post?

You never mentioned any trans codes, so I assume there were none.