New Life for a truck passed its prime

[RedHeartbeat]

Tap into the wire coming from the PCM, try that first.

[flattopwill]

Tap into the wire coming from the PCM, try that first.

Will do. Thanks.

[low91]

Well I can't figure out which cluster wire to tap into. The diagrams I looked at showed more than one speedometer related wire. One from speed sensor, one from the ECM labeled vss, and I think one more.
I think I read somewhere that pre-91 trucks have the drac box in the cluster.

As far as I know its pre-92. My truck(91) didn't have one, but my brothers 93 did. You should have two wires running from the trans. directly to your cluster, lt. grn/blk and a ppl/wht. I got no idea how to hook it up though, I swapped to a 95+ interor long ago, much simpler wiring. I've got a 91 wiring service manual if you need to know what wire runs where.

[flattopwill]

Ya that's what I meant to say - '91 an earlier.

Ya I saw those two wires but I also noticed the wire from the (TBI)ECM labeled "vss input". I have a diagram of the cluster connector that my friend gave me I just don't know which wire needs to be connected the the speedo output from the new ECM. I kinda figured someone had done this already. If not, I guess I'll start connecting wires til it works.

[flattopwill]

Well its in and running.....sort of.

First few starts it would surge a lot and usually die unless I kept it running. My friend came by on his lunch break and plugged in his diagnostic tool real quick. It showed MAF failed, TCC solenoid failed, and something else I forgot. After a while I guess the computer learned because it would mostly idle on its own but die every once in a while. I was real excited because the cam sounded awesome especially on open long tube headers lol. I started taking video and about 11 secs in it died. It didnt spit and sputter or surge or cough or anything just died like the ignition was cut. Now it wont start at all just crank over. It has fuel pressure at the rail but I cant see spark on the plug wire. My friend from the dealer told me to pull a plug wire off the coil and try to see some spark the old fashioned way but I couldnt get it too. It seems to me that pulling the plug far enough off the coil to see it spark would be too far for the spark to jump? I think this is a minor problem that can be fixed once we plug the diagnostic tool back in later. Here is the vid I was taking when it just died.



Now, the REALLY BAD NEWS. When I went to put it on the lift I tried to back it up to get it aligned on the lift and it wouldnt move itself. It doesnt go into any gear. When the selector is in any position besides PARK it acts like neutral. Unless, you guys have other ideas, Im guess there is something seriously broken in the trans. I dont know what to do about it yet but Im guessing Ill have to have the whole trans rebuilt. Hopefully its something minor not hooked up right for the shift linkage inside the transmission.

Can anyone help? Ive been awake for about 24 hrs so Im going to bed and then get up about 8ish and go back over there with my buddy who did my wiring/has a diagnostic tool/is a GM tech to see what we can figure out.

BTW, here are some more pics of parts and stuff if anyone is still interested.

RevMax torque converter



When we were putting in the motor mounts. For a while I really thought they werent gonna fit.


The slip joint that was added to my drive shaft.


About 90% in.

[flattopwill]

No one knows bout the trans?

[flattopwill]

OK, this is what we figured out.

I dunno what we did to the trans but it atleast moves now.
After plugging in the scan tool it showed the truck to be running(barely) pig RICH. The long term fuel trims are 25% and the short term are 50% I dunno what it is. I think maybe Allen forgot to tune it for flex fuel injectors. I posted a thread in the tuning and diagnostics forum here http://www.ls1truck.com/forums/pcm-t...tml#post363928 where I posted a lot of diagnostic info hopefully someone can make somethin out of it.

Here is the crappy vid I took of the scan tool while it was idling.

[keniff]

when you added tranny fluid was the truck running? the converter could be empty if you didnt let it to operating temp then top it off.

[flattopwill]

ya i checked it after it got to operating temp and it looks good. except its leaking out the the main connector

[farmtruc]

That truck will not run right and without a maf? It's maf tuned, it needs a maf to run, hence the failed maf code.

I didn't forget to tune for anything, even the injectors, the info you supplied is already setup for flex fuel injectors, the Z vin.

Until you get some exhaust on that truck, those o2's are never gonna read correctly and make the truck run like crap. O2's don't work well so close to the open collector.

looks like you're getting closer.