4.3 Vortec Problems

[fishinwrench]

I had a '90 W/T with a 4.3 and that was great truck.  No issues at all and although it wasn't crazy powerful....it never failed to do what I asked of it.   I often wish I still had it.

[snagged in outlet 3]

21 hours ago, fishinwrench said:

We need a good Auto Mechanic in this place !     

I thought @MrGiggleswas a mechanic.  

[fishinwrench]

1 hour ago, snagged in outlet 3 said:

I thought @MrGiggleswas a mechanic.  

Sweet!   Let's test that.

@MrGiggles I have a 04 Tahoe 5.3 with random electrical glitches.   Sometimes when you open the door you get the normal "DING-DING-DING-DING...", and other times you get a very faint "ding-ding" (only two dings) that you can barely hear. And often no dome light illumination upon opening one door.....but open another one and the dome lights come on (no pattern to which series of doors need to be opened). 

Sometimes doors lock as soon as I shift into gear.....other times they don't lock until I get up to 15-20mph. (irritating as hell when you're launching a boat or just moving it back a few feet in the driveway).  One day the horn quit working.... but it started working again and hasn't failed again YET.

I've studied this a bit and I think it is probably a bad ground somewhere.....but WHERE?   And if I'm correct, then where should I look, or can I just install a few additional ground straps somewhere to cure all of this weirdness ?

Help! 🤔 

Oh yeah....and I also suspect that the odometer reading is way off.  Shows 160k but I'd bet good money that it has less than 100k.   The trip meter once read 74 miles after only driving less than 25. Speedo and tach seems accurate and no issues with guages, no codes or SES light.

[MrGiggles]

1 hour ago, fishinwrench said:

Sweet!   Let's test that.

@MrGiggles I have a 04 Tahoe 5.3 with random electrical glitches.   Sometimes when you open the door you get the normal "DING-DING-DING-DING...", and other times you get a very faint "ding-ding" (only two dings) that you can barely hear. And often no dome light illumination upon opening one door.....but open another one and the dome lights come on (no pattern to which series of doors need to be opened). 

Sometimes doors lock as soon as I shift into gear.....other times they don't lock until I get up to 15-20mph. (irritating as hell when you're launching a boat or just moving it back a few feet in the driveway).  One day the horn quit working.... but it started working again and hasn't failed again YET.

I've studied this a bit and I think it is probably a bad ground somewhere.....but WHERE?   And if I'm correct, then where should I look, or can I just install a few additional ground straps somewhere to cure all of this weirdness ?

Help! 🤔 

Oh yeah....and I also suspect that the odometer reading is way off.  Shows 160k but I'd bet good money that it has less than 100k.   The trip meter once read 74 miles after only driving less than 25. Speedo and tach seems accurate and no issues with guages, no codes or SES light.

The dome light and dingers are probably the door ajar switches (they are inside the latch) sticking, thinking the doors are closed even when they're open. The ones in my 06 act up as well sometimes. 

There are two settings for the auto door lock feature. One locks them as soon as you drop it in drive, the other locks them when you hit a certain speed (I think it's 15 mph). You change the settings in the menu with the steering wheel buttons.

The dingers go through the radio on our trucks. The faint tone could be a lot of things, but I would get the latches fixed up first and see what that does.

Tire size will throw off the speedometer, odometer, and speedometer. If you're not running the stock tires, they will be off. GMs are easily programmed with any plug in tuner. If you've got the stock tires, someone may have changed the settings in the past if the truck has ever had a tuner on it. Although if it not consistent this is probably not the issue.

 

[aarchdale@coresleep.com]

Me next:

I have a 2006 Ram with  hemi.  Truck starts every morning no problem and runs fine. But if i stop at walmart or the grocery store and let it sit for a few minutes it struggles to start unless i pump the gas pedal once. It has never not started or left me stranded. But if its hot you really have to crank it or pump the gas to get it to start.  (250,000 miles on the clock)

[fishinwrench]

5 hours ago, MrGiggles said:

You change the settings in the menu with the steering wheel buttons.

No steering wheel buttons. 

[snagged in outlet 3]

I dumped a 99 Yukon due to electrical issues.   Doors and door locks.  My neighbor has a 2019 vette that won’t lastch the trunk/engine compartment.  He’s had it to 3 dealers and a retired GM service tech.  Nobody can fix it.  It’s stuck open with constant warning bell.  Computers and electronics are great...   when they are working correctly.  Goes back to @fishinwrenchwanting a stripped down model without all the gadgetry.  

[ollie]

Like I said earlier, I had a 90 S-10 with the 4.3 and a manual transmission and that truck never let me down. Some of you know the way to Eureka Springs via 62 and when you start getting close you are climbing hills all the time. I could have that truck loaded to the gills and I never once had to take it out of 5th to climb those hills. Truck was super light in the backend though and would get stuck on anything somewhat wet or slick! As in the tires would just spin. lol 

[MrGiggles]

5 hours ago, fishinwrench said:

No steering wheel buttons. 

I found this for models that don't have the wheel buttons. Apparently that didn't show up into 05 or 06.

As for why yours seems to be flip flopping between modes, that's a tough one.

Programmable Automatic Door Locks

(If Equipped)

Your vehicle may be equipped with an auto lock/unlock

feature which enables you to program your power door

locks. The following instructions detail how to program

your door locks.

To enter the program mode you need to:

1. Pull back on the the turn signal/multifunction lever

all the way toward you and hold it while you

perform the next step.

2. Beginning with the ignition in OFF, turn your key to

ON. Return it to OFF and turn to ON again. Then

return it to OFF. Once you do this, you will hear the

lock switch lock and unlock.

3. You are now ready to program the automatic door

locks. You will have ten seconds to program once

you release the turn signal/multifunction lever.

The following is a list of the available

programming options:

Press the lock side of the lock switch on the driver’s

side door panel once to turn on the automatic door

lock feature. All doors lock. No doors will unlock.

Do the same twice to turn off the automatic door

lock feature. No doors will lock or unlock. Auto

unlocking will not work if auto locking is turned off.

Press the unlock side of the lock switch on the door

panel once to unlock the driver’s door and lock all

other doors.

Do the same twice to unlock all the doors. All doors

lock and unlock. (This is the factory setting).

Do the same three times to turn off the automatic

door lock feature. No doors will lock or unlock.

You can exit the program mode any time by turning the

ignition to ON.

The automatic lock feature will lock all the doors when the

vehicle speed is greater that 15 mph (24 km/h) for two

seconds. Your vehicle left the factory programmed to have

all the doors unlock once the key is removed from the

ignition and lock when vehicle speed exceeds 15 mph

(24 km/h). See your dealer for more information.

If the lock/unlock switches are not pressed while in the

programming mode, the respective auto lock/unlock

setting will not be modified.

 

As for adding grounds, that is a possibility. There should be a couple on the engine that go to the body and frame.

If you wanted, it is not hard to add them. Big stereo guys do what they call the the big 3 upgrade, replace the alternator charge wire, ground from battery to engine, and the ground from battery to body with heavy 4 or 1/0 gauge wire.

The factory charge wire and ground straps are comically undersized for the alternator capacity, those braided ground straps don't last long in the rust belt, and if the truck has ever had any engine/transmission work done, who knows if they got put back in the right place or even put back at all.

[MrGiggles]

 

7 hours ago, aarchdale@coresleep.com said:

Me next:

I have a 2006 Ram with  hemi.  Truck starts every morning no problem and runs fine. But if i stop at walmart or the grocery store and let it sit for a few minutes it struggles to start unless i pump the gas pedal once. It has never not started or left me stranded. But if its hot you really have to crank it or pump the gas to get it to start.  (250,000 miles on the clock)

That would fit the diagnosis for leaking injectors. 

A fuel pressure test would tell you. Fuel trims would be in the negative too.