my ls swap died...

[truckdude239]

Well it lives they traced it back to a bad computer ground which is weird cause i had the computer grounded but they added 2 more grounds and it fired right up had 58 psi fuel pressure.

[truckdude239]

He thinks my lean codes where caused by the ground issuse but im not sure

[dec010974]

I glad everything worked out truckdude239

[Clyde65]

great! I am glad it was something reasonable and simple. I hope everything continues to roll smoothly for you!

[truckdude239]

It is runnin good but it now has a u0107 code ibhave to figure out

[BR3W CITY]

u0107 is tac module mismatch/disconnect. If you just had a grounding or electrical issue, then this one isn't a surprise. It sounds like your truck is having grounding issues in general. I'd make sure you have good grounds on the "big 3" then make sure there aren't any un-grounded circuits OR any positive circuits shorting to ground.

[truckdude239]

Yea aparrently when i did the swap i "forgot" to bolt the wires to the back of the cylinder head.... they where just hanging there bearly touching the block they told me the bolt them back and redid my ground wire runing to the ecm and it fired right up with normal fuel pressure i cleared the u0107 and going to see if it comes back but the thottle is working.

[Liltroy]

wait...the ecm is suppossed to be grounded???? More info please!! Im having horrible issues with my swap and cant figure out why...maybe Im not grounding everything properly??

[truckdude239]

Mine would start when i frist did the swap i ran a ground wire to one of the case screws on the ecm and it started right up

[Liltroy]

mine fires up easy and idles good but wont rev over 2500 and will only give me 20%tps with engine running. At this point Im going to try anything and grounding the ecm is free so why not?

[BR3W CITY]

Originally Posted by Liltroy

mine fires up easy and idles good but wont rev over 2500 and will only give me 20%tps with engine running. At this point Im going to try anything and grounding the ecm is free so why not?

The ECM is internally grounded under normal circumstances. IF the internal grounding is bad, or if random line interference is causing noise (way more rare), then externally grounding the case helps solve some problems. You do need to be careful if you do this however: It could theoretically allow the PCM to become the path of least resistance if a current spike occured (welding on the chassis, getting struck by lightning, accidentally creating a short from the alternator). That shouldn't scare you off, just keep the battery disconnected at all times any electrical systems are being worked on your car.

[nsulacountry]

Originally Posted by BR3W CITY

The ECM is internally grounded under normal circumstances. IF the internal grounding is bad, or if random line interference is causing noise (way more rare), then externally grounding the case helps solve some problems. You do need to be careful if you do this however: It could theoretically allow the PCM to become the path of least resistance if a current spike occured (welding on the chassis, getting struck by lightning, accidentally creating a short from the alternator). That shouldn't scare you off, just keep the battery disconnected at all times any electrical systems are being worked on your car.

+1!!!

If welding on the vehicle, ANYWHERE!!! Or, otherwise energising the vehicle... ... ... (IE: Juicing the Flux Capacitor behind the seat with a Mr Fusion or Lighting via the Belltower...)

DISCONNECT THE Battery!

CT, (Crazy Engineer)

[TooTall]

Originally Posted by truckdude239

so i swaped in a 4.8 4l60e into my 71 its been runnign for a while now and ive been battleing p0171 and p0174 system lean codes, i cleaned the massf low and checked for vacumn leaks but did not find any. drove it codes came back sometimes it would not idle so i replaced the mass flow with an ac delo reman, on my way home ti started bucking and jerking and then stalled out and wouldn;t start back i think i lost the fuel pump in the tank an ac delo ep381 with corvet filter

if you have the orange intake gaskets, replace them. They're known for leaking. Get the green intake gaskets, the GM or Felpro ones will work.