Tach just tells you engine speed. Not timing. It's like using your speedometer to figure out where you are on the map. There is a mathematical connection there, but you wouldn't use one to tell the other.
CK5
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Tbi, map sensors, and headaches
- Thread starter Alex guadalupe
- Start date
Tach just tells you engine speed. Not timing. It's like using your speedometer to figure out where you are on the map. There is a mathematical connection there, but you wouldn't use one to tell the other.
So when you take your distributor cap off, there is a small sensor back there with 2 clip wires.I forget which sensor that is, but it was always my issues. Also, when its idling spray down some of the vacuum lines with some carb cleaner.. if you have cracks, you will have a surge, its suprising how much vacuum effects these motors.
My buddy has an 89 Blazer and it was doing all sorts of stupid sh1t too. Swapped injectors, CTS, bought new plugs wires cap and rotor. During the cap and rotor install we saw a ton of rusty looking dust inside the cap. his distributor pretty much ate itself. We swapped in another TBI distributor I had laying around after giving it a quick cleaning. Truck fired immediately, revved to 1200 rpm or so, then settled to a nice smooth idle in seconds. Never skipped another beat. All his issues were related to the distributor killing itself.
My own 90 Blazer had a bad CTS sensor when I bought it. That bad sensor was the reason I was able to get it for $700 at the time. it wouldn't run more than a couple of minutes before it'd puke black smoke and refuse to restart.
My own 90 Blazer had a bad CTS sensor when I bought it. That bad sensor was the reason I was able to get it for $700 at the time. it wouldn't run more than a couple of minutes before it'd puke black smoke and refuse to restart.
OP, if you *decide* to do so, look into buying a complete replacement distributor. Don't go throwing a module at it, then a pickup coil, then a rotor, then a cap. You have to remove the distributor to get the pickup coil out, whenever/if ever you decide to dig into the distributor, at this age, just replace the whole thing. That is generally cheaper than buying all the components.
Depending on how long you think you will have the truck, a spare distributor isn't a terrible thing to have around.
I'm not saying it is or is not your problem. As I've seen a few times now though, people start replacing parts before asking for help, and when it comes to ignition, the "replace parts or replace distributor" usually comes too late, as the person having the problem has often already tried one component, which hurts the economy of getting a complete new distributor.
Depending on how long you think you will have the truck, a spare distributor isn't a terrible thing to have around.
I'm not saying it is or is not your problem. As I've seen a few times now though, people start replacing parts before asking for help, and when it comes to ignition, the "replace parts or replace distributor" usually comes too late, as the person having the problem has often already tried one component, which hurts the economy of getting a complete new distributor.
We had similar issues with my truck and @secutright blazer, we even got a bad reman out of the box, the dizzy controls a lot on a tbi because the tach input tells the ecu when to pulse injectors, if that is off it won't run for nothing.
Oh a bad coil will make it act funny too.
@Alex guadalupe You said you were in fort Irwin. Do you live in the Victor Valley area?
I live on post in the barracks
