6.0 and 4L80E conversion

[Gordfire]

I installed a 6.0 and 4L80E combination in my 79, the engine runs great with no problems, but the trans does not seem to be controlled.

It starts off as it is slipping then shifts hard as if the torque converter is locking up, (2 speeds only).

I had the harness reworked by Dynatech and it is missing the Input shaft speed sensor, could this be a problem?

The engine and trans were working perfectly in the donor vehicle before I removed it.

Anybody have any ideas or suggestions. Worst case is change out the trans to a non PCM controlled trans, don't want to do that, but if I have to I will.

[RedHeartbeat]

If you had the harness modified by Dynatech Motorsports I feel for you. Those guys appearantly know nothing about LS1 type engine/transmission conversions. I would get a wiring schematic for the pcm in the truck and verify all the pinout and sensor connections. I hear day in/day out of them screwing up the pinout configuration on the pcms. Dynatech is starting to realize they don't know crap about the LS1 types and no longer do the LS1 type conversions. Do a web search on "Dynatech Motorsports" and you will find pages of people dissatisfied with their piss-poor work. They lack the knowledge and tools to reprogram the PCM correctly. I would suggest you contact Allen/Farmtruck and have him reprogram your PCM correctly before you change your transmission. Allen has a "Light" version of his programming services that is reasonably price.

[honkydaddy]

Got to have a speed sensor or the trans won't know to shift.

Dynatech left my sensor out,luckily the wires were still there.I replaced the connector and plugged it up and it worked OK.Allthough Oscar took some pins out of my PCM connectors that I had to replace

Believe I have a VSS connector if you need one.I have some PCM pins too.

Definately don't want to change the trans.

[Gordfire]

Boy, I could use some pins for the PCM connector.

Yes, I have had it out with Oscar. He took 3 months to rewire my harness. Still owes me a fuel pump and air filter which I paid for, he wired in the wrong MAF sensor connector, and the MAP sensor was at the wrong end of the harness. Charged me 350.00 to have the PCM reprogrammed, called Nelson Performance, (who he had do it), they said they only removed Vats for him .

I have a VSS sensor that is connected at the output shaft. I was reading the service manual, and it also has an input shaft speed sensor, I don't know if that one is required for the trans to shift also.

Do you guys know of a good Scanner or laptop program to get my DTC codes, I am going to try and troubleshoot my transmission problem.

I don't want to change my trans either!!!!

Thanks guys

[honkydaddy]

What year and model PCM and harness you got

I can check on a scan tool too,have some OTC's.They're pretty exspensive for doing a single vehicle.I just found a good one,but was going to see if Greg wanted it.Dynatech screwed him too.His won't even run I get them quite often and there's always Auto Tap.Think you can get a single GM program for about $250.Haven't tried any of the other programs.

[Gordfire]

I have a 2001 6.0 Vortec PCM and harness.

I just bought Scantool over the internet for 139.00, comes with cables and software. I had to buy an additional scantool due to my wife's Toyota or it would have cost 109.00.

I haven't attempted to remove any pins from the PCM connector. Do you have to use a depinning tool, or do they just pull out?

I would also like to be able to reprogram my PCM on my own, any thoughts on that?

[honkydaddy]

Sounds like you've got the round ones.Think(not a 100% on this,don't have one to look at)) you'll have to open the back of the conn. at the wiring,and take the clear plastic cover(prys off,gently)over the male side(PCM).The pins should pull out from the wire side.Oscar has probably allready got it out,so you'll be adding,should push right in.Put the covers on.Square ones are similar,have a tab built on them that you depress with a bobby pin.They just push in too,which is probably what you'll be doing.Oscar's probably been there.

Look and see what shape your pins are,I'll check which one's I've got.Be tomorrow when I go to work

I'm working on programming my own LT1,looks like something like LS1 Edit for you.Think a bunch of guys on here talk to Allen(farmtruc) about that.Don't know if it will work on a Vortech.Need to find out

[honkydaddy]

Let me know how Scantool works,I was looking at something those people made for a PDA.Think it was them

[RedHeartbeat]

What kind of scantool did you find?

[honkydaddy]

Hey Greg,
Actron III scan tool with the OBD II Generic cartridge.It reads codes,erase codes,view data,view freeze frame,O2 monitor test,continuos test,non-continuos test,has an expanded protocal with on board systems,and code look-up.
You can buy carts and cables for OBD I vehicles(domestic)This is OBD II Generic.I've had a few of these and they're pretty nice for a basic scan tool.Tried one on Gm breed car and it wouldn't communicate,so some of the first OBD II vehicles it doesn't work.Believe it'll work on about 90% of OBD II.Used them on 00 and 01's and they worked fine.Checked this on my 97 F PCM.
Seen them sold under different names,sunpro,balkamp,and others.You're not going to do any programming with it,but beats the heck out of a code reader. Believe they're still selling these,didn't check Actron website.

PM me if you're interested,I'll let you have it for what I gave for it.Be under a $100 with shipping.

Oh,it's got the instructions,video,cig power cable(don't know why they put that in there powers up from the ALDL),OBD II cart,OBD II cable,scan tool,and has a vinly carrying case.Looks brand new.