Andy’s 1995 CCLB 7.4L TBI to Vortec Swap

[Christian Steffen]

VIN locked means that it disables key power by activating the security perimeters thereby locking the pcm.

What would active that though?

 

[andy396]

I can pretty confidently say that for GMT400s all passlock does is disable the fuel pump relay. It’s not more sophisticated than that. I’m sure in newer models with keyless start features it can do all sorts of fancy things.

 

[JCribb]

I can pretty confidently say that for GMT400s all passlock does is disable the fuel pump relay. It’s not more sophisticated than that. I’m sure in newer models with keyless start features it can do all sorts of fancy things.

This is what I was trying to get at, but lost the words to explain in detail.

 

[andy396]

Now for the embarrassing part. I take the valve cover off. The lifters look good. They're only about 1/32" depressed when the valves are closed. However, after all the cranking and pump priming I've done up to now, the top of the head is bone dry. Not a single drop of fresh oil. It's not getting enough oil pressure to pump up the lifters. Ugh!

After more discussions with my Dad, who is my go to engine rebuilding guy, we come to the conclusion that I must have left out the oil galley plugs. I can't believe it, but that's got to be it. I remembered many of the other steps, but I couldn't say I specifically remembered installing them. Particularly the front ones. They'd been starring me right in the face when I put the timing set on. Anyway, I start the painful process of removing everything to get to the timing cover off. Get it off and sure enough...

You must be registered for see images attach

This still doesn't really explain the intermittent pressure pulses I was getting on the compression gauge. But oh well.

 

[andy396]

As I was looking back through my pictures I came across this one.

You must be registered for see images attach

If you zoom in you can even see it then.

You must be registered for see images attach

Not the best day of my life.

I think the greatest challenge of this project has been trying to accomplish it in bits and pieces, here and there.

 

[ZRoe]

Kudos for diving in as deep as you did. We all make plenty of mistakes, some of us are honest enough to admit it and some (you included) are brave enough to post it for the rest of us to learn from.

If it makes you feel any better I know a professional mechanic that left a shop rag in his 6.0 powerstroke rebuild and couldn't figure out why he had a weak cylinder....

Sent from my moto e5 supra using Tapatalk

 

[andy396]

Thanks, hearing even the pros have bad days as well helps a little.

 

[BNielsen]

Kudos for diving in as deep as you did. We all make plenty of mistakes, some of us are honest enough to admit it and some (you included) are brave enough to post it for the rest of us to learn from.

If it makes you feel any better I know a professional mechanic that left a shop rag in his 6.0 powerstroke rebuild and couldn't figure out why he had a weak cylinder....

Sent from my moto e5 supra using Tapatalk

My dad built a 383 for his dirt track car many moons ago, got it all together, got it in the car and fire it up only for it to make the most god awful noise, spit fire and die.
He dug into it and as soon as he took the carb off he found out what it was, he left a towel in the mouth of the intake to keep from getting junk down in the engine and just forgot about it. Wasn't a good day at all.
-----------
Are you considering doing an 0411 swap once you've got the truck running @andy396?

 

[andy396]

Are you considering doing an 0411 swap once you've got the truck running @andy396?

Yes sir. Picked one up a few weeks back out of an ‘01 Express Van for $40 w/connectors. Before I installed the engine harness I spliced in wires for the trans gear indication as well as wires for tow/haul and valet. I put those through the firewall connector using pins from my parts harness out of the diesel. I’ve heard that with EFILive it might be possible to have a secondary ignition map triggered by the valet pin. I think it would be pretty cool to be able to select which map to use based on whether or not you’re running 91 or 87 octane. For now I’m on the original black box. That’s a project for another day.

 

[Christian Steffen]

Yes sir. Picked one up a few weeks back out of an ‘01 Express Van for $40 w/connectors. Before I installed the engine harness I spliced in wires for the trans gear indication as well as wires for tow/haul and valet. I put those through the firewall connector using pins from my parts harness out of the diesel. I’ve heard that with EFILive it might be possible to have a secondary ignition map triggered by the valet pin. I think it would be pretty cool to be able to select which map to use based on whether or not you’re running 91 or 87 octane. For now I’m on the original black box. That’s a project for another day.

Maybe @Supercharged111 can dive into the valet mode details? Either way the 0411 has low and high octane tables and uses knock learn to interpolate between the two. so you really don't need to activate a different model if you don't want to.