I spent the afternoon replacing the plugs & wires on my '98...when I went to start it, check engine light came on. AutoZone scanned it, and it was code P1345. I searched the forums and came up with some information about a CASE relearn...but my question is, will driving my vehicle with that code present hurt anything? It runs fine.

I just did the intake gaskets too (which of course includes distributor removal) but I marked and took pictures of how it was positioned and didn't have any codes pop up after I did that.

One thing I did notice, however, is that my dist. cap seems loose. I noticed this when replacing the wires. I can grab it and spin it either way. Both dist. cap screws are present and I made sure to wrench the hold-down bolt very good when I reinstalled the distributor. Is there anything else I should start looking at?

Edit: solved. Hold down bolt on distributor came loose.

98 Jimmy, 4x4

 

Ah.. the seemingly magical properties of the vortec 'cam sensor'!
START with tossing that cap and putting on an AC Delco. If it IS {allegedly} an AC Delco, take it back and exchange it.
I know of no distributor cap on any car that allows any 'twisting' or 'spinning' when fastened to the distributor. The reason I say that is that it always impressed me how precise the keying of the cap to the distributor housing was.

https://blazerforum.com/forum/diagno...plained-35138/
This is interesting possible cause:
and if that's the case, then a loose cap as well might do it. I could definitely see it happening if the rotor was hitting the cap contacts, at all.

What I would do to try to fix it: You MAY be a tooth off but that may have also been at the 'fringe' of the case learn.
After replacing the cap and making sure the rotor fits well and snug, hold the dist firmly while lossing dist hold down bolt. Turn the dist and retighten bolt at opposite edge of the bolt hole. If you can tell difference in driveability {doesnt run as well} do it again and tighten the other edge of the hole.
If light doesnt turn off, then you can either try to move the dist a tooth both directions.. or just take it to a dealer or a shop that has a tech II scantool.

 

I will go check the cap and rotor again tomorrow when I have more light.

If the dist. cap is screwed down properly and the hold-down bolt for the distributor itself is torqued properly, what exactly is spinning when I turn the cap? Is it the shaft itself along with the rotor? The cap rotates along with the part it is screwed into, so the cap isn't just freely spinning by itself. I will try to take a video of it as well tomorrow so it's easier to see what I'm talking about. Whatever it is, it just seems strange and I don't remember it doing this between the time I replaced the intake gaskets and today when I replaced the wires and plugs.

 

it is possible that the ears are broke off your dist. which would keep the screws from holding the cap in place, Plastic dist was another bad idea from GM, aftermarket fixed that with a alloy housing

 

Hmm I tried pulling up on the cap, too, and it didn't budge...I'm pretty sure the ears are fine, but will double check tomorrow in the light just in case.

 

Shouldn't be able to move the distributor cap, it's possible that's what's setting the P1345. The crankshaft position sensor relearn has nothing to do with P1345. P1345 sets if camshaft retard is more than ~25 degrees off, (1 tooth on the distributor). Connect a scan tool capable of reading camshaft retard, check and adjust it. Spec is zero degrees, +or- 2 degrees. It is adjusted by rotating the distributor. If you can't get it within spec by rotating the distributor, remove and discard the factory hold down bracket and replace it with a SBC, (small block chevrolet) hold down bracket, available at most auto parts stores. This will make the distributor fully adjustable.

 

Problem solved. Apparently the hold down bolt for the distributor came loose while changing my plugs and wires yesterday. Tightened it back down & cleared the code and it didn't come back...but in the process, I managed to blow out one of my brake lines...incoming thread about that.

 

thx for posting back. Amazing how they manage to make the hold down seem like an afterthought and hard to get leverage on..
Why I bought one of these, when I was doing a lot of engine work

 

Do you have a link to that set? I would love to have them, just to make sure that bolt is tightened down enough. I couldn't get in there very well with a straight 10mm, so I'm worried it'll come loose again.

 

1/4" drive 10mm swivel socket and a 6" extension gets right at it:

Snap On 10mm Swivel Socket, 1/4 Drive, 6 Point, Part# TMUSM10 | eBay