1983 Chevy S-10 83 S10 poor performance when going up hills

Inspect and test all the following listed below:

Oxygen sensor
Catalytic converter
Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)
Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Cap and rotor

Note:If it doesn't apply disregard.

Thanks for your reply Razmataz, unfortunately i have already replaced and checked everything you put down : /. Thank you for your quick response though :)

EDIT: I have yet to check the EGR Valve, how would i go about testing it?

Use a vacuum pump on the EGR valve,apply vacuum on it -this will cause the EGR valve to open and make the engine stall or run rough if its doing its job-or press on the diagphram to open it

Ok i did the vacuum test on the valve, and the engine ran rough and almost stalled.

Im still having issues with the performance : / Is there anything else i can do?

Did you check and test everything I've mentioned on my 1st post if you haven't do so-there's a lot that can reduce engine performance

Yes i have tested everything, But there was one thing not on the list that i'm having issues testing witch is the HEI(ECM) unit inside the Distributer.

There is 2 wires coming from the distributer going to the coil, looks like a negative and a positive wire, i turned the ignition on put the ground of the volt meter to the engines ground, then tested both wires and got around 12.43 volts in both.

I also used the meter to test the - and + wires coming from the unit itself, the voltage dropped down to 8 volts, then right back up to 12 while cranking, and it stayed at 12 for the duration instead of pulsing.

I think that was the correct way to test it or am i doing something wrong?


Oxygen sensor - does not apply
Catalytic converter - replaced
Dirty fuel injectors - does not apply
Bad MAP sensor - does not apply
Bad TPS sensor - does not apply
Bad or dirty MAF - does not apply
Low fuel pressure - new fuel pump & filter
Vacuum leaks - all hoses replaced
Bad gasoline - clean
spark plugs - replaced
Bad plug wires - replaced
Weak ignition coil - replaced
Cap and rotor - replaced

If there's a problem with the distributor pick coil and the ECM inside you won't be going up hill-you'll have a no start condition-You sure its not transmission problem

i'm positive, its a manual transmission with fresh oil, shifts nicely too.

Well it does have a problem starting but thats a choke issue that i cant figure out, if i go under the hood and manually set the choke it starts right up.

EDIT: Had the HEI Unit tested. it passed.

i did however find out if i hold the choke half open(as in wired it half open) It runs just fine, just that the secondary wont open. but when i press the pedal it actually wants to go.

Also the Choke light on the dash will no go off, but there is voltage coming through the wire, until the engine warms up.

This has me really confused. Because now it has me thinking that it was getting to much air and not enough gas. but its a brand new fuel pump (mechanical) and filter.

i had the same thing happen 2 my 1983 s10 1st thing the carburetor needed a new one 2nd i had a leek on the bottom of the carburetor that was giving me bad fuel air mix after all that it worked fine let me know if that worked email me at [email protected] if any ? k

Alright well i went to my local Autozone store, told them what was going on, he told me to take the top of the carb off, and make sure the nothing was plugged.

Well i did just that, however there was a ALOT of carbon build up blocking the secondary fuel passage along with a little in the main jets, with ALOT in under the float, cleaned it all up now it doesn't cut out anymore..now when i floor it and it opens the secondary and it has a tiny bit of hesitation, but ALOT more power.

However the choke light is still on, with a tiny bit of hesitation when the secondary opens. Might be normal?

@pimp946312, Thanks for the reply, but this was a brand new carburetor, don't know why i had all that carbon in there, but i believe the carb is working as intended now :)

well with the light there is some thing more rong with ur s10 if it has tiny bit of hesitation and the light is on then if i was u look at all the wires see if they r snug or have any kind of exposed wires that can be the last thing wrong with ur truck let me know i am working on my 1983 s10 as well and we had the same things wrong if i can help any more let me know.

Well it doesn't cut out..but now were back to the not pulling the hills tested it today, it pulls them in third gear at about 25, when the speed limit is 55 : /

EDIT: Ok so i decided to check the resistances of the new spark plug wires..i get to the #3 wire, pull it off use the meter i get a 1. so i look in the end...there was no connector inside...haha. so it blasts up the hills after replaced it with one of my old wires. So im gonna go get a refund and some new wires. Oh and after i replaced that, the choke light now turns off. O.o

nice i think ur all done let me know if any more ? but it looks like that's it. :)

I'm still having issues with the electronic choke, I cant seem to find the right setting. it's either not turning off the choke after its warmed up, or the choke wont engage.

Also..the wire from the choke is only putting out like 0.50 volts, takes about a half hour for the linkage to actually move.

The relay is getting 13ish volts, so is the heater under the carb, maybe i could splice a wire for the choke from it?

If i keep having issues with it i'm going to stick a manual choke in, haha


EDIT It still wont hold its speed going up hills, sigh.

EDIT 2: Maybe the power piston isn't working in the carb?

EDIT 3: Well i took apart the carb again, cleaned up the power piston, works a little better but it still cuts out for like 2 secs when you floor it even if you do it slow, no leaks around the base. i just want it to stop cutting out, its really annoying.