What the hell is going on with my 5.3?
06-13-2022, 02:11 AM
#1
What the hell is going on with my 5.3? So, i started working on my project vehicle a complete novice (still am) and it just occurred to me while reading a thread about Degreeing a Camshaft. I always thought all you ever had to do with a LS would be line up the dots on the cam gear and crank and bammo. Then some things started to click for me. Last year i picked up a project from a dude who ran a automotive shop, he did some really "What ever works" stuff, like electrical connections of two wires was twisted wire and electrical tape, etc. anywho he had swapped a legit LS3 cam into the Gen3 5.3, however the LS3 cam does not have a cam sensor gear on the back, it has to get a cam sensor reading off the front timing cover, So he put a whole new dual timing chain on the engine and did a Gen 3 to gen 4 cam sensor swap on the stock computer. I purchased a HP tuners dongle and recorded the truck via the scanner doing a quick pull (if you want to watch = ) and noticed the timing advance would max out, i saw 60 degrees in there but the engine seemed to run fine.... I did a cam swap a little later and just lined up the dots. Now my question is, the cam i put in has the cam sensor gear on the back (ala gen 3) and now i plan on having my holly terminator run the engine with the gen3 cam sensor. What are the chances that the cam and crank are so out of phase he had to do some insane tuning shinannigans to get it to run? If he put a dual timing chain on the 5.3 could he have put it on out of sync? (i don't know if the crank is keyed to accept the gear in only one position or if its just a slip on fit) I was going to use the wizard on the terminator and get someone who knows what they are doing to tune it but i am scared of wounding the engine.
06-13-2022, 10:13 AM
#2
Moderator
iTrader: (4)
Join Date: Jul 2014
Location: My own internal universe
Posts: 10,446
Received 1,838 Likes
on
1,146 Posts
Hopefully I can set your mind at ease...
Cam sensor signal has no effect on ignition timing. Only tells the Ecu which cycle it's on. I.e. cylinder 1 TDC on compression or exhaust stroke. So that's not affecting anything unless it's just hard to start.
Crank timing gear is keyed. It can only go on one way, unless it is a multi-keyed gear for adjustable timing.
As for dot to dot -- you can be off a tooth using the dots and not know it. Especially if you are not removing the oil pump. I like to put the cam Gear dot at the top center and verify the crank dot is also at 12:00 as a secondary check. But then I degree it anyway because I have been burned by timing sets off by nine degrees before.
Cam sensor signal has no effect on ignition timing. Only tells the Ecu which cycle it's on. I.e. cylinder 1 TDC on compression or exhaust stroke. So that's not affecting anything unless it's just hard to start.
Crank timing gear is keyed. It can only go on one way, unless it is a multi-keyed gear for adjustable timing.
As for dot to dot -- you can be off a tooth using the dots and not know it. Especially if you are not removing the oil pump. I like to put the cam Gear dot at the top center and verify the crank dot is also at 12:00 as a secondary check. But then I degree it anyway because I have been burned by timing sets off by nine degrees before.
The following 2 users liked this post by Darth_V8r:
G Atsma (06-13-2022), swathdiver (06-14-2022)
06-14-2022, 05:59 PM
#3
Hopefully I can set your mind at ease...
Cam sensor signal has no effect on ignition timing. Only tells the Ecu which cycle it's on. I.e. cylinder 1 TDC on compression or exhaust stroke. So that's not affecting anything unless it's just hard to start.
Crank timing gear is keyed. It can only go on one way, unless it is a multi-keyed gear for adjustable timing.
As for dot to dot -- you can be off a tooth using the dots and not know it. Especially if you are not removing the oil pump. I like to put the cam Gear dot at the top center and verify the crank dot is also at 12:00 as a secondary check. But then I degree it anyway because I have been burned by timing sets off by nine degrees before.
Cam sensor signal has no effect on ignition timing. Only tells the Ecu which cycle it's on. I.e. cylinder 1 TDC on compression or exhaust stroke. So that's not affecting anything unless it's just hard to start.
Crank timing gear is keyed. It can only go on one way, unless it is a multi-keyed gear for adjustable timing.
As for dot to dot -- you can be off a tooth using the dots and not know it. Especially if you are not removing the oil pump. I like to put the cam Gear dot at the top center and verify the crank dot is also at 12:00 as a secondary check. But then I degree it anyway because I have been burned by timing sets off by nine degrees before.