New to me 98 Silverado 5.7

[Bouncerboytimmy]

I bought a new to me 98 Silverado 5.7 while the previous owner gave me a questionable History.

I came across the truck on a craigslist ad and was dying to get back into a truck (sold my last one over 6 years ago and regretted it ever since).

So now I have a beat-up truck with an unverifiable repair history and the title exempted the odometer (shows just over 200k so I'm betting it sat for a while), anyways, the list of problems is sure to be expanded in the upcoming posts but for now I will post what I know.

The list upon purchase:

1) code P0300 - Random misfire

2) Code P1345 - Crank-cam pos correlation

3) Leaking rear diff cover

4) Cracked Dash

5) Sticking Ignition key cylinder - Takes ALOT of jostling to turn the key

6) Groaning doors

7) Passenger door only opens from the outside

Apart from cosmetics (peeling clearcoat, scratches and dings, and a 3rd door dent that was welded), There isn't really all that much I could see that was wrong with the truck, just had the piss beaten out of it, ran hard and tossed to the side after some basic maintenance wasn't followed thru with.

I am trying my hand at reviving this truck my wife has affectionately named "Tonka".

Armed with some basic tools and a new scanner that provides live data, here goes nothing.

 

[boy&hisdogs]

Those codes sound like you need a new timing chain. Try a crank position sensor first though they are relatively cheap and super easy.

The groaning doors can be partially fixed by replacing the hinge pins and bushings. Not too bad if you have someone to help hold the doors while you take them off.

Passenger door probably needs the interior handle replaced. They are made of super crappy pot metal and plastic.


This is all stuff I had to deal with on my own 98 5.7 that just passed 200k and needed a million little things fixed.

 

[Bouncerboytimmy]

Since I have gotten the truck I have Replaced :

1) Plugs - rusted and corroded to the color orange/red
2) wires - some were "repaired" with electrical tape
3) Cap and Rotor - the old cap center terminal/bearing fell out when I removed it and the rotor had carbon deposits
4) cam pos sensor - cheap sensor, and seeing how bad the other parts were, totally suspect

My current issue is that the truck has a rough idle and my scanner shows the 1st cyl timing hovers around +20dg TDC, popping the P1345 code. my question before doing anything drastic, is what simple diagnosis can I perform to rule out other possibilities? how would I test the ignition coil? do I have to have a fuel pressure gauge to test the fuel line? Following the methodology of diagnosis, I need to rule out simpler fixes before I crack open the timing cover and my understanding is that I have a few places to look.

1)Spark - do I keep following the ignition circuit? The next step up is the coil
2) Fuel - I have heard that a faulty injector spider can cause this type of misfire, is this correct? if so how would I diagnose or what numbers should I look at on the live feed?
3)Air supply - MAF sensor malfunction? How do I verify this?
4) Timing itself - Do I slot the distributor hold down and turn the distributor? I don't have a spare cap around so drilling a hole to see arcing is kind of sacrificing a possibly good rotor

if there is another wacky cause someone has come across im all ears, I just need simple diag solutions without part throwing, Thats too costly a way to repair.

 

[Bouncerboytimmy]

update on the misfire diag

live feed shows fuel trim is way off on one bank, leading me to believe the injectors could be the source of the misfire.

could this be correct?

also, does anyone know of a simple means of putting in door actuators for power locks? or would this require too many things on the electrical front? new computer?

this truck is kind of a restomod situation since I'm planning on getting it running correctly and then upgrading various things to a more modern standard, Bluetooth, better bushings, and possibly rear discs.

I'm all ears for pointers on which direction to take, and I see "take it to a mechanic" as a last resort reserved for the really tricky problems

 

[boy&hisdogs]

My truck was doing that with the fuel trims (20% higher on one side) and I did have to replace the injectors. One was totally dead and a couple others weren't spraying consistently. I also had to replace the timing chain and a bunch of other small stuff all around the same time so I don't know what exactly was causing it, or if it was a chicken-egg thing.

There's an injector tester tool you can buy that lets you activate each one individually to see if any are dead. You can also hook up a pressure gauge to the fuel line and see if they are all spraying the same amount. Watch how much the psi drops each time you spray one and they should all be within a pound or so of eachother, each time. Make sure you run the fuel pump each time though so you start with the same pressure.

 

[Erik the Awful]

My current issue is that the truck has a rough idle and my scanner shows the 1st cyl timing hovers around +20dg TDC, popping the P1345 code.

The factory timing isn't adjustable by turning the distributor. Your CMP whatchacallit needs adjustment, and you need a scan tool to set it. I ditched my factory computer, so I'm no help with instructions.

 

[emarkay]

The factory timing isn't adjustable by turning the distributor. Your CMP whatchacallit needs adjustment, and you need a scan tool to set it. I ditched my factory computer, so I'm no help with instructions.

I just set mine last week, I used a cheap clear bluetooth ODB scanner and the Android DashCommand app, with the PID unlock for my truck year ($20 total for app and year unlock). Had to add PID Cam Retard CKP / CMP Correlation to the data grid on app. Spec is +2 to -2 degrees from what I read.

Kept the distributor hold down bolt just tight enough so it would stay put after turning it. Throttle it up above 1000rpm to update degree reading. Turn it in spec and tighten down.

I went from +20 rough idle and coding, to smooth as butter at +0.8, starts as it should now. No more P1345

Used information in this thread

https://www.gmt400.com/threads/scanner-tool-to-set-the-timing.42183/page-3

and this youtube

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