I have a 1984 S-10

[nuwt]

I have a 1984 S-10 that has 270,000 miles and I have this problem for the last 140, 000 or so. If it is below freezing and I drive hiwaay miles it starts to shut down. You can hold it to the floor at it wont go over 500 rpm's. It idles the same, no change when gas pedal is pressed. I stop turn it off and wait a few mins at it will run great. if i stay in stop and go traffic it isnt as bad. it is as if it freezes up when driving hiway speeds. I even put cardboard over radiator. I have changed carbs. plugs, wires , etc. This truck does NOT have a computer. It is vacumn advance, it was the base model, 6900 dollars new. it runs and drives great above freezing with no problems.
Anyone with any ideas?
I just call it my summer truck.

[OverBoardProject]

Just a reminder for everyone with better idea's 84 is still carburated

I think that the carb is probably icing up.

Chech the thermostatic butterfly (sorry I don't know the name) thing in the air filter, and make sure that the hose underneath going to the exhaust manifold is there and in good shape.

Plus check your EGR valve.

[dmbrisket 51]

is the mc possibly not working right, leaving the choke on?

[Cam1959]

Originally Posted by nuwt

I have a 1984 S-10 that has 270,000 miles and I have this problem for the last 140, 000 or so. If it is below freezing and I drive hiwaay miles it starts to shut down. You can hold it to the floor at it wont go over 500 rpm's. It idles the same, no change when gas pedal is pressed. I stop turn it off and wait a few mins at it will run great. if i stay in stop and go traffic it isnt as bad. it is as if it freezes up when driving hiway speeds. I even put cardboard over radiator. I have changed carbs. plugs, wires , etc. This truck does NOT have a computer. It is vacumn advance, it was the base model, 6900 dollars new. it runs and drives great above freezing with no problems.
Anyone with any ideas?
I just call it my summer truck.

I have 83 s10 2.8 carb 4x4. seems something is freezing at lower temps induced by highway speed since you say at city speed just below freezing it ok ?

Maybe water in tank, fuel lines, carb float bowl. Put in gas line antifreeze, the type that says with water removal which any would do but this type i think may do better.

if above not help. maybe windchill effect problem is just on carb. when it acts up, with it still running and warmed up, take air filter cover off and see how open or not the upper choking valve is. if not fully open that may be prob. try opening it to see if help. adjustment is 2" round black plastic cover wit h3 screws on driver side of carb.

lubricate all those levers on pass side of carb and be sure no vac leak anywhere around engine or lines to front axle or transfer case or in/under dash for air flow redirectors.

[nuwt]

Originally Posted by Cam1959

I have 83 s10 2.8 carb 4x4. seems something is freezing at lower temps induced by highway speed since you say at city speed just below freezing it ok ?

Maybe water in tank, fuel lines, carb float bowl. Put in gas line antifreeze, the type that says with water removal which any would do but this type i think may do better.

if above not help. maybe windchill effect problem is just on carb. when it acts up, with it still running and warmed up, take air filter cover off and see how open or not the upper choking valve is. if not fully open that may be prob. try opening it to see if help. adjustment is 2" round black plastic cover wit h3 screws on driver side of carb.

lubricate all those levers on pass side of carb and be sure no vac leak anywhere around engine or lines to front axle or transfer case or in/under dash for air flow redirectors.

I have changed carbs( rebuilt) and installed new tank when original sprung a leak. Installed a manual choke( thought it was choke first)
the vavle in breather I have tried it open all the time and closed all the time, no difference. Changed filters and used gas antifreeze treatment. Removed the straight fan and installed a clutch fan. only thing original is dist. and I may try that next. even wrapped fuel line from fuel pump.

[OverBoardProject]

The fuel freezes right in the carb it's self so wrapping the fuel line won't help. I've also seen it happen with clean fuel where there was no chance of water problems. (although never on a S10 before)

Try cleaning your EGR. I'm told that they allow exhaust gas to warm the carb up during the winter. Hopefully this helps.

[maxwedge]

Originally Posted by nuwt

I have changed carbs( rebuilt) and installed new tank when original sprung a leak. Installed a manual choke( thought it was choke first)
the vavle in breather I have tried it open all the time and closed all the time, no difference. Changed filters and used gas antifreeze treatment. Removed the straight fan and installed a clutch fan. only thing original is dist. and I may try that next. even wrapped fuel line from fuel pump.

If it is carb icing, the base of the carb is heated by exhaust passages in the manifold that can become blocked and not all ow the heat to reach the carb base, the manifold has to come off to determine this.

[OverBoardProject]

Originally Posted by maxwedge

If it is carb icing, the base of the carb is heated by exhaust passages in the manifold that can become blocked and not all ow the heat to reach the carb base, the manifold has to come off to determine this.

I'm told that it's the EGR that opens and closes these passages. So that's where I would start

[nuwt]

Thanx!!!
new ideas never hurt!!

[MIKE PERRY]

hey man i have the same problem have tried the same remmedies as you have taken the truck to transmission shop and still nothing, completely stumped, under the carb but above the intake their is a box with wires have been told a heater for the carb not sure maybe acting up. anyway the problem is ruinning my experience with s-10's......

[OverBoardProject]

I don't want to say look into an 85 carb if they're 2.8L engines but the only problem that I have with my carb is the choke doesn't work.
And that's with my EGR blocked off so those exhaust passages aren't functional

[nuwt]

Still guessing here. maybe I should retire my S-10.
270,000 plus, I think I will put iton light duty. Other than the freezing up at highway speeds at below freezing temps. I would give my S-10 a 100% truck.

[Cam1959]

Originally Posted by nuwt

Still guessing here. maybe I should retire my S-10.
270,000 plus, I think I will put iton light duty. Other than the freezing up at highway speeds at below freezing temps. I would give my S-10 a 100% truck.

I'd keep it going as long as possible as long as you don't let it rust away.

I doubt it's carb throat icing because you said you've been using gas antifreeze and covering front of rad. don't leave air blocker right against front of rad or inatake area of rad may get too hot, melt solder and leak upper intake area of rad. i just put towel down over front grill, using hood and bumper to secure it, so rad still has some air flow.

Do you still have the black thick plastic rock/brush guard under front bumper ?

Could air moisture be getting drawn into leaky vac line somewhere, and freezing on windchill exposed area of line on highway, ruining your timing control ?

If this is 4x4, there are 2 lines running down from vac ball, over exhaust pipes, where they burn if too close, to top of transfer case. One of the vac diaframs could have small leak in it. The one on right fender that engages front axle. Some more under dash for inside air flow directing. a maze of vac lines behind or below radio for all that. shake the vac ball to see if water in it. put in 4wd and see if diafram for that works or makes vac leak noise.