Slow crank after LIM repair

[jcob2]

Just finished head gasket and LIM repair job. The motor runs just fine. The only thing different about it now is it cranks kind of slow, like the starter is having extra resistance turning over the motor. Not dead battery slow, but it kind of has that same sound to it. It still always starts, but before the repair the motor used to crank effortlessly for startup. What could have changed and how to fix? Only think I can think of is that maybe the rockers are too tight? But I used a brand new Sears torque wrench to set them, so I doubt that is the problem. Manual said 124 in-lb for my 1998 Monte Carlo 3100.

I just torqued them all down with the motor at the same point of rotation. I did this because the manual didn't say anything about needing to set the lifters on the base circle of the cam before tightening, which is a procedure I have seen done on other motors. Did I do wrong??

[SappySE107]

89 in lb is the torque I believe for rocker arms. Alldata says 124 and really, it shouldn't make a difference. If it runs ok, I don't know what it is. Battery getting weaker? If it runs fine, I don't know what could be wrong and related to the starter.

[tractorman]

I don't have the manual in front of me... but those torque values seem low to me. I'm pretty sure my '94 Corsica's rockers torqued to 18 ft-lbs. Could be wrong.

Regardless, rocker arm adjustment isn't going to affect how the engine cranks. I don't know of anything you would've messed with that could be related unless you didn't reconnect the alternator or something... and I think that would be obvious.

[SappySE107]

We have the specs on this site.

[jcob2]

Chiltons says 89 in-lb for early 90's 3.1's, and 124 in-lb for late 90's 3100's. I can't remember the cutoff year at the moment, but I do remember both of those torque specs in the manual... it was model year dependant.

I was mostly concerned about whether I needed to torque with the lifters on the base circle of the cam, or not. Comments?

[geoffinbc]

You didn't remove any grounds when working on the motor did you. Battery cables nice and tight?

[jcob2]

Didn't touch the grounds. Yes, cables are tight.

It is an original battery (9 yrs old), so I wouldn't be surprised if it were to crap out soon. It just seems waaay to coincidental that it would start showing signs at the exact moment I fire up a repair job. It's gotta be something else.

I guess I could always try swapping in another battery from one of my other cars to rule it out.

[PCGUY112887]

Maybe it is from sitting while you worked on it? Battery started to go...

Mine was original when I pulled it last winter, started to do exactly what you are saying.

Also the torque specs for the 3500 rocker arms are 24 lb ft... why would the such similar 3100 engine be so much lighter than that?

[ollopa]

Double check that you don't have too much ignition timing advance.
That can cause hard starts even though the engine will run great once it's started.

[SappySE107]

He didn't say anything about reprogramming the ECM so I doubt that is the problem.

[jcob2]

Stock ECM.

Took me 6 weeks to do the job. I'm very busy and just put in a couple hours here and there, which is why it took so long. I guess maybe 6 weeks of sitting could make an old battery start doing this... but I did disconnect the ground so it shouldn't have had any load on it at all.

[IsaacHayes]

Yeah 6weeks sitting with an old battery can defiantly cause it to discharge. Old batteries have higher self discharge rates.

[PCGUY112887]

My battery was totally disconnected for that long in my 3500 GP while doing my swap, after hooking it up it woulden't hold a charge at all.

Have the battery tested for free at Autozone, I bet it won't hold up.

[Rhedalert]

aren't the rocker arm bolts torqued low, but then add an additional 60 degrees of tightening? Something like that...

EDIT:

ROCKER Arm Bolt 10n/m +30° 89in/lb +30°

http://wiki.60degreev6.com/index.php?title=L82_Fastener_Tightening_Specifications

[jcob2]

Fixed it. It was just an old dying battery after all. I guess you guys were right about stressing the battery by letting it sit for 6 weeks. The battery was the original 1998 AC Delco. Got almost 10 years out of it! Can't ask for more than that!

With the new battery, it cranks up 100% normal.

Thanks for the advice!