1989 Chevy Ignition Timing & The Little Tan w/Black Stripe Disconnect Wire

This is the most complete information, video and gif of the timing process for the 1989 Chevy ignition.

There is very little information on the internet about the 1989 Chevy 1 ton (Don’t even bother looking for the dually)! I intend to change that! Don’t get me wrong, there is page after page of information pertaining to the light weight 1500. Several about the medium weight 2500. But the heavy duty 3500….forget it! Here you have found one of the rare websites that has information for the Chevy 3500 with the 454 timing!

Today I’m going over the ignition timing and I’m also going to show you where to find that, ever elusive, little tan wire with the black stripe that you need to disconnect to set the timing! Let’s get to it!

We’ll be digging into the moving parts of the engine and some serious grease and oil, so my lady friends, and guys, pull back those long locks into a pony tail or bun and remove the fake nails so you don’t lose one down the carburetor or somewhere just as hazardous! No loose clothing or dangling ties and scarfs either!

The ignition timing for the 1989 Chevy Silverado 3500 (And 2500 & 1500) the correct specifications are:

  • Spark Plug Type: CR43TS
  • Spark Plug Gap: .035
  • Timing: 4 degrees BTDC (Yes, it is 4. Not 8 as you may see elsewhere.)
  • Firing Order: 1, 8, 4, 3, 6, 5, 7, 2

The best place to find information like this about your specific truck is on the engine label. When you open the hood it is right there above the grill. It’s an aluminum material sticker with all the information about the timing, belt routing and smog. This information is specific to your exact vehicle so use it above all and others! My 1989 sticker is dog eared but it is still there!

When I need to pick up spark plugs, or the distributor I just put in the truck, I check Amazon. The choices are endless and I like that. I don’t like to be boxed into a specific product my local parts store endorses with this old truck. The link below takes you straight to the vehicle identification page of the ignition parts section on Amazon.

Ignition parts

The Distributor

The distributor is the heart of the ignition system assisted by the coil and the MAP (Manifold Absolute Pressure) they make up the upper portion of the starting system. There is also:

  • Starter – Located underneath the truck on the passenger side of the engine near the oil pan.
  • Starter Relay – Often confused with the starting solenoid. The starter relay is located at the firewall next to the positive distribution bus on the passenger side. The starter relay controls the fuel pump and the fuel level display.
  • Neutral/Clutch safety switch. The neutral safety switch won’t allow the engine to start unless it is in Park, or Neutral for an automatic or the clutch is depressed in a manual.
  • Starting Solenoid – Commonly confused with the above starter relay. The starting solenoid is located on the drivers side fender wall. The starting solenoid connects the power from the battery to the starter motor. The starting solenoid controls the 12v to the starter motor.
  • Oil pressure switch – This switch will not allow the ignition signal pass if the switch is malfunctioning or if the oil pressure is nil.

Once the signal from the ignition switch request has passed through all of these checks and balances, only then, will the engine turn over. After the engine starts there are two components that continue to work hard. They work just as hard as they do for the start engine sequence and those are the distributor and the spark plugs. Yes, the coil continues to put forth the energy for the spark plugs, but the coil has the resilience of solid state components. It is not in constant motion as is the distributor particularly and the violent atmosphere the spark plugs endure with the pistons causing a continual high pressure then sudden vacuum effect every few seconds.

The Distributor in Constant Motion

The distributor is in constant motion when the engine is running, constant! The threat of cracking, abrasions, scoring, etc. are common maladies for the distributor. The O ring separating and sealing the distributor and the engine can, and does, crack. This will produce a constant oil leak at the distributor Not enough to cause a “real” problem, but enough to leave a pool of oil on top of the intake….constantly.

On the other hand, a crack, or chip, of the distributor and you will notice a rough idle, sometimes an engine will misfire from this, or stall.

The distributor is very easy to replace on these trucks. Seriously, it’s a matter of removing the old one and dropping the new one in. That is all! And the price is surprisingly reasonable, depending on your taste. Below is the standard replacement distributor for the Chevy 3500.

Or, since the 1989 is considered a classic at 30 years old now, you may want to start putting in fancy replacement parts. I know I am!

The Spark plugs

Spark plugs, along with the distributor, are the work horses of the engine. The constant exposure to high pressure explosions and an instantaneous vacuum effect defines the life of your spark plug. It’s amazing they can last as long as they do! 50,000 miles is the suggested mile marker for new plugs. Some iridium plugs can claim a life of 100,000 miles! That’s just crazy.

Don’t give this much thought, just do it. The 454 engine is a beast. So, do your truck and yourself a favor and keep it running with good plugs. Again, these are considerably low priced and make all the difference in fuel economy, engine idle, power, it’s all affected by the spark plugs.

This link goes to a huge variety of spark plugs on Amazon. Titanium Bosch spark plugs, double titanium plugs (Yeah, they have that!), Champion copper plugs, the list goes on!

Spark Plugs of Every Kind

Here’s a quick run down on changing your spark plugs. That’s how important it is, I’ll even tell you how to do it!

When you’re changing your spark plugs only remove one at a time. IE: Start on either the left or the right side, it really doesn’t matter, remove the first spark plug wire by grasping the boot down at the engine, twist and pull. This can be a bear sometimes. Spark plug wire removers (Sorta like bbq tongs but shaped for a wire.) can be your best friend when getting these boots off the plug sometimes. If you pull the spark plug wire alone, you stand a huge chance of ripping the wire out of the boot and off of the connector. If you do this, don’t despair! I have a How to Repair a Spark Plug Wire page here (This link goes to my article on axleaddict.com) just for you.

I have used vice grips and a screw driver as leverage to remove a particularly difficult spark plug boot. Grasp the boot with the end of the vice grips BUT NOT SO FAR THAT YOU CATCH THE END OF THE SPARK PLUG INSIDE THE BOOT! If you get the end of the spark plug itself as soon as you engage the vice grips the ceramic spark plug will break!! When you know for sure you only have rubber boot in the vice grips, lock them and take a screw driver and leverage it against a sturdy part of the engine and leverage the vice grips until they pull the boot off straight out. I don’t want to catch any grief in the comment section on this method! I have used vice grips for years to remove the damn boot. Saves my knuckles and my sanity! Thank you very much!

Once you have the boot out, use a socket, maybe with a small extension, to unscrew the old plug, check the tip for carbon, burns, damage, etc., gap the new plug and put it in. I use a lubricant to put the plug wire back on (A little spit, okay.).

When you put the spark plug wire back onto the new spark plug, you want to hear it click onto the spark plug. If it doesn’t click on, then it is not attached. Sometimes squeezing the end that attaches to the spark plug before putting it onto the spark plug will tighten up the connector inside. Don’t squeeze too hard or it won’t go on at all.

When you’ve completed all the spark plugs, it’s time for the timing. Before checking the timing there is a tan wire with a black strip on it that breaks out of the wiring harness at the back of the engine near the firewall and the distributor. It can be tricky to find to say the least. The video shows you exactly where it is!

Now that you have the tan wire with the black stripe disconnected you can hook up your timing light (Yes, the 1989 Chevy 3500 still uses the good ol’ timing light), red to the positive on the battery, negative to a good source of ground and the induction to the first spark plug wire. Route all the wires so they are clear of the engines moving parts. Start the truck and set your timing. Below is the firing order for the 7.4 liter and 5.7 liter with an animation of it in motion!!

The 1989 Chevrolet Silverado 3500, 7.4 liter, 454, ignition system at work!!

When you have set the timing remember to reconnect the tan wire with the black stripe! You are all set.

Great job!

Leave a Reply

Your email address will not be published. Required fields are marked *

five + 8 =