I removed everything in my sig.


I had to repin: 80e-60e
Remove supercharger and put on stock manifold with fuel rail.
I converted a 4x4 60e to 2wd. I put in a re-manufactured stall speed, new flexplate. Put the stock exhaust manifolds and y pipe on.

I start the truck and key off after about 3 seconds In order to avoid damage because the truck violently stumbles.


Only code I got was the p0315 crank relearn code. I didn't want to restart it to see if any more codes would trip.

Here are my thoughts
1. bad gas in the fuel rail (has been sitting in there 3 years or so)
2. torque converter ballooned? I don't know what the re-man quality control tolerance/specs are but maybe not that good?
3. wrong flexplate I was told it "should be the correct one" I forgot to check the p/n. It was dished with a 3 bolt mount to verter/ 6 bolt mount to crank.
4. coil packs maybe I switched these up? I had to take the wiring harness apart (yeah I should've labeled em').
5. manifold gaskets. I know these are the revised gaskets that are supposed to address leakage. I used bolts from the hardware store so they aren't the gm bolts that have the rubber compression deals on them.

ANy of you guys experience symptoms like this? I don't really want to start the truck if I could do any kind of damage so hopefully I can get someones expertise here. Because of this I can't check for vacuum leaks.
Thanks in advance.

Hoping it is bad gas although i heard bad gas can bend valves. Not sure how true that statement is.

 

I'm gonna rule out everything above and say that it is the converter or flexplate. I installed the verter correctly. I have never had this issue before and the info below is how I have always installed them


The following are measurements you can make to insure the torque converter is all the way in the transmission:
GM-TH350, Powerglide=1.125" from bellhousing to the converter pads.
GM TH400 = 1.187" from bellhousing to converter pads.
GM 700 R4, 4L60E, 200-4R = 1.125" from bellhousing to converter pads.
GM 4L80E = 1.030" from bellhousing to converter pads.
Distance may vary +/- .050".

After the transmission bellhousing bolts are tightened, check to see if the torque converter will turn by hand. Push the torque converter back into the transmission as far as it will go. Using feeler gauges or calipers (or drill bit)measure the gap between the flexplate converter mounting pad and the torque converter mounting pad. If gap distance is between .060" and .187" it is OK to bolt up the torque converter. If the gap is greater than .187" install a .060" flat washer between the torque converter and flexplate.

I am thinking the verter might be out of alignment
Perhaps the flexplate is out of alignment or not the right one.
time to take it apart again I guess.

 

I'm thinking that rather than an alignment issue, the torque converter OR flexplate could just be out of balance. I've seen brand new flexplates that had a weight fall off during shipping or whatever....or just welded in the wrong place on the outer ring. New ain't always perfect.

 

I just did a little research and it looks like the gen IV 5.3's or at least the ly5's have a different flexplate. All the ly5's I have seen online have 3 triangular holes and 3 small round holes as opposed to the G181 that I installed which had 6 round holes. Both flexplates have the 3 bossed mounting pads and are both dished.

 

Which flexplate did you use when returning to stock?

 

Balance/alignment- that is what I was going for.

I used the g181. This has the 6 bolt flex to crank bolt pattern with 6 circular "weight saver" hole pattern in the middle of the plate. 3 bolt converter pad to flex.

If the new flexplate that I get to pick up at 6 doesn't work, I am thinking the harmonic balancer might've been damaged when I removed the alternator bracket and rested it on the frame while I was removing the supercharger. It might have made contact with the hb and threw it out of wack.

 

I hope you get it squared away. Seems like you have had a bunch of strange issues with the truck, so I hope you get it resolved quickly! And so I can buy that crossmember from you

 

it was the flexplate. crazy how much it was shaking

 

Glad you got it fixed. Thanks for posting up what ya found.. never know when info like this could be useful.