93 K2500 Suburban 454 Holley Sniper Upgrade

[LC2NLS6]

1. Dots on the 454 on the cam sprockets need to be both at 12 o clock. That is 1 TDC (compression - needed to use the Holley clear plastic hyperspark dizzy setup tool), if you do dot to dot like every other engine, it is 180 out.
2. Read the instructions, I hooked fuel feed to the regulator. Only after rewiring the fuel pump relay, verified fuel pressure, did I realize maybe the feed and return were swapped.
3. Still haven't found a good switched 12v while cranking, so I just use an alligator clip to battery to trigger the switched relay.

Tons more part throttle power. Trans might need more sensors. Check engine light is on, need to figure that out maybe just pull the bulb.

 

[LC2NLS6]

The factory lead that went to the coil, grab that pink wire - it is hot when ignition is either Run or Starting. Now the touchscreen stays on while cranking and fires right up.

You must be registered for see images attach

 

[LC2NLS6]

Now I need to remove the GM Goodwrench "security system" It is a rats nest under the dash.

 

[LC2NLS6]

Also feels like I need to hook the factory temp switch up to let factory trans controller know it. Documentation related to this point here (I'm not using megasquirt, just a reference on the trans I found):

http://www.msgpio.com/manuals/mshift/4L80E/4L80e.html

 

[LC2NLS6]

That was the final piece - need the temp sensor hooked up that used to go in the front of the manifold. I didn't have any extra ports, so it is dangling on the top of the manifold for now. Seems to work. Pulls hard to 4400 is when it shifts. The sniper has its own temp sensor that went where that one would go.

Also had to extend the fuel feed to clear the throttle bracket with a -6 male/male and union female/female.

 

[LC2NLS6]

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[Schurkey]

1. Dots on the 454 on the cam sprockets need to be both at 12 o clock. That is 1 TDC, if you do dot to dot like every other engine, it is 180 out.

With cam and crank sprockets at 12:00, that is #1 TDC COMPRESSION.
Crank at 12, cam at 6, is #1 TDC EXHAUST.
They're both #1 TDC.

Chevy small block is the same, as is Chevy 90 degree V6, and most other engines I can think of. There's some exceptions, notably the ancient Ford "Y-Block".

Check engine light is on, need to figure that out maybe just pull the bulb.

Wow.

 

[Supercharged111]

If the PCM is missing a bunch of crap it thinks it should see, but never will, then yeah yanking the bulb is the right answer. Or wire it to the Holley.

 

[CrustyJunker]

Nice work! Does it run?

Edit: Missed the memo. Looks good!

 

[LC2NLS6]

Runs great.

I meant 1 TDC compression with the dots at 12 o clock. I wish someone would have told me that 25 years ago. Explains a great many things as to why every single cam and chain swap I've been 180 out.

I'm sure the SES light is because the Holley is controlling the engine or maybe its there when I left the temp sensor unplugged, I guess I could read the factory codes. I left the factory computer in place to control the 4L80E transmission. Completely random, but it has the upgraded harness into the trans, post '94 change, so that is good they did that when the trans was rebuilt. Shifts out around 4300-4400. All the factory gauges work. The sniper has a nitrous controller...150 wet shot would be fun.