I have a 93 S10 Blazer 4.3 V6.
Its has been sputtering after the truck warms up and gets worse after idling.
The engine has no power when I try to accelerate or get up a hill. It feels like its bogging down or not getting the right amount of fuel.
My volt reading is really high too. its at 18v and it should stay around 15v right?


Any help is greatly appreciated. Thanks

 

UNDER 15v
Verify that voltage with a DMM from the batt post and alt post to block, but YES. Do not run engine till you figure it out.

 

Ok I'll try that today. Thanks, Could that play some part in why the truck is acting funny?

 

Definitely.. if under 10 or over 16.

 

what would cause that to happen?

 

a. bad alternator {internal voltage regulator} lights would also seem extra bright
or
b. bad volt indicator
or
c. not usually..poor connection from block to chassis frame and batt neg to frame.

 

It has been doing this since December. And it fried my alternator and battery so I replaced both of them and the belt 3 weeks ago.

Where is the volt indicator? And is it easily replaced?

I disconnected the ground from the chassis and sanded it for a better connection and it still has the same problem.

Im starting to think the ECM might be going. I did the OBD1 test and all it gave me was code 12 over and over. Which isn't a trouble code. Its just the code that means that the diagnostic system is functioning properly.

If the ECM was on the fritz could it be the root of the problem?

Thank you for all your help so far by the way.

 

and also, my fuel pump has been replaced but i can't get ahold of the mechanic who changed it because he no longer works at the place. So i don't know if he used an aftermarket one or not.

Could a fuel pump or fuel filter cause the truck to idle rough and bog down durning acceleration?

 

Both the filter and pump could cause your issue, but if they have been replaced recently then chances are you are OK. I would start with a few other things:

If possible, verify your voltage reading with a different meter. Next, check your voltage at the pump with the car just keyed "on" without running and again with the car running. If you get 12v when its not running, and 18v when it is running then your alternator is putting out too much voltage. I'm not 100% on these trucks, but rockauto lists a separate voltage regulator apart from the alternator. If this is shot, you could be getting too much voltage from your alternator. To make sure, check the voltage at the battery post like mentioned above. It should never be more than about 13-15 volts when running.

 

Let's be clear.. the only problem you should deal with is that voltage reading. Either the gauge is wrong and everything is okay in your charging circuit.. OR you are chancing frying everything again!!!
The volt indicator/gauge is in the dash, right?
WTH! Never thought of that. Why is a nineties production vehicle using a remote regulatorBTW... As Far as I know, there's a red warning band on the gauge. Wonder what they meant that?