1993 Chevy c1500 4.3 power issues

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Little blue

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I’m new to this form but am in need of help and this is going to be long so please bear with me. I got the truck in may of 21 and at the time was not starting well or at all and was burning substantial amounts of coolant so I went through and replaced the head gaskets, intake gaskets, throttle body gaskets, alternator, all the pulleys and belt and I also replaced the plugs, wires, cap, rotor, coil, and ignition control module all of which are ac delco parts.The truck was doing great until about January maybe a little before that. It was throwing codes left and right, barely running and had zero power. So I went through and replaced the o2, tps, both temp sensors, map, egr vac hoses, grounds, pcv valve, and the ignition switch. It’s still not running right but all the ses lights have went away. If i floor it from a stop it bogs to almost 40-45 then feels almost like turbo lag because at or around 45 it kicks and takes off. Anything below that it’s a complete dog. I had an aluminum 6x10 with a small zero turn on it going up a small hill and had to have it pinned to stay at 30 and burned a 1/4 tank of gas in 50 miles. And my standard gas mileage went from 14 to almost 10. The oil also smells burnt and like gas. Also when I have people behind me they say it smells like straight gas. Also sometimes when I pull to a stoplight it will try to die then smooth back out then rev way up for just a second and try to send me into traffic. Please tell me what you think this could be anything helps. Thanks
 

1998_K1500_Sub

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Model year?
Engine mods?
ECU mods? (different "chip" if 1995- / reprogrammed if 1996+)
Compression test?
Ignition timing checked?
Starts well cold? Starts well hot?
Catalytic converter still in place?

If you have ever hooked up a scan tool...
- engine coolant temp is reported correctly when hot / cold?
- TPS responds correctly through entire range of throttle / pedal?
- O2 sensor(s) responding properly?
- long term / short term fuel trim values are...?
- any stored codes in the ECU?

These are a few things that come to mind, others will comment I'm certain :waytogo:
 
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Little blue

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Model year?
Engine mods?
ECU mods? (different "chip" if 1995- / reprogrammed if 1996+)
Compression test?
Ignition timing checked?
Starts well cold? Starts well hot?
Catalytic converter still in place?

If you have ever hooked up a scan tool...
- engine coolant temp is reported correctly when hot / cold?
- TPS responds correctly through entire range of throttle / pedal?
- O2 sensor(s) responding properly?
- long term / short term fuel trim values are...?
- any stored codes in the ECU?

These are a few things that come to mind, others will comment I'm certain :waytogo:
It’s a 93 and everything is stock still has factory chip, I have yet to do a compression test, ignition time is at 0, starts good but when cold sounds like it has a cam in it for a few minutes. I do not have a scan tool since it’s obd1, tps tests good, temp is good, and no codes. The cat is still there but exhaust is cut right after the cat.
 

Schurkey

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I have yet to do a compression test,
It's time to do that. ALSO test the fuel pressure.

ignition time is at 0,
With, or without the single-wire EST connector disconnected?

starts good but when cold sounds like it has a cam in it for a few minutes. I do not have a scan tool since it’s obd1,
WAY past time to correct that. You NEED a scan tool when dealing with computer-controlled vehicles. It's exceedingly difficult to diagnose computer issues when you can't communicate with the computer, verify computer inputs, or assess computer outputs. A REAL scan tool will also communicate with ABS, body computer, transmission, stability control, instrument cluster, and any other computer-controlled devices the vehicle might be equipped with.

The cat is still there but exhaust is cut right after the cat.
Is the catalyst plugged? Melted?

The EGR is very likely backpressure-sensitive. A screwed-up exhaust system could cause EGR-system issues.

Have you ever looked at the magnet on the distributor shaft? TBI distributors often have cracked magnets that cause various ignition issues.

This is from a V8, the six-popper should be similar. The typical crack happens in the rivet area.
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1998_K1500_Sub

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Have you ever looked at the magnet on the distributor shaft? TBI distributors often have cracked magnets that cause various ignition issues.

On a 1995 4.3L V6 VIN W S10 Blazer I once had, the reluctor wheel assembly on the distributor shaft wasn't firmly attached and it would slip on the shaft ever-so-slightly over time, thus causing the timing to become retarded. This took place over the span of years.

The story begins like this:

I had to continually adjust the timing on the Blazer because, over time, it would become retarded a few degrees.

I had no friggin' idea why the timing was becoming retarded. At first I thought maybe the hold-down clamp was loose. Later I wondered if the timing gears / chain were becoming excessively worn. Later, I would learn that the reluctor wheel was slipping on the shaft.

I'll continue with the story...

Then one day I was driving at roadspeed and I suddenly noticed the engine was really low on power; throttle response was poor, the engine would misfire and generally run like crap. Fortunately, I was near a friend's house and I managed to drive the Blazer into his shop, there. I put a timing light on it and found the timing was WAY retarded, by about 20deg IIRC. Of course I still didn't know why the timing had become so retarded.

It just so happened that I had another distributor off a 1995 4.3L V6 VIN Z which was identical, and I compared the two. See the pictures below.

The first picture is of a GOOD reluctor wheel and the second the bad one from my V6. Note the orientation of (a) the notch in the distributor shaft to (b) the reluctor wheel assembly.

What had been happening, evidently, is the reluctor wheel had slipping little by little for a few years. Then finally, it slipped a LOT.

I disassembled the bad distributor and pulled the shaft and reluctor wheel out as an assembly. By hand I tried to twist and rock the reluctor wheel on the shaft, but it was tight. How on Earth it slipped on the shaft escapes me.
 

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rsweet88

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I’m new to this form but am in need of help and this is going to be long so please bear with me. I got the truck in may of 21 and at the time was not starting well or at all and was burning substantial amounts of coolant so I went through and replaced the head gaskets, intake gaskets, throttle body gaskets, alternator, all the pulleys and belt and I also replaced the plugs, wires, cap, rotor, coil, and ignition control module all of which are ac delco parts.The truck was doing great until about January maybe a little before that. It was throwing codes left and right, barely running and had zero power. So I went through and replaced the o2, tps, both temp sensors, map, egr vac hoses, grounds, pcv valve, and the ignition switch. It’s still not running right but all the ses lights have went away. If i floor it from a stop it bogs to almost 40-45 then feels almost like turbo lag because at or around 45 it kicks and takes off. Anything below that it’s a complete dog. I had an aluminum 6x10 with a small zero turn on it going up a small hill and had to have it pinned to stay at 30 and burned a 1/4 tank of gas in 50 miles. And my standard gas mileage went from 14 to almost 10. The oil also smells burnt and like gas. Also when I have people behind me they say it smells like straight gas. Also sometimes when I pull to a stoplight it will try to die then smooth back out then rev way up for just a second and try to send me into traffic. Please tell me what you think this could be anything helps. Thanks
I'd start with the easy stuff like the fuel pressure, most commonly the main coperate for a lot of probs. U can also do the safety pin on ur OBD1 to get the codes if any no scanner needed.,(plenty of vids on YouTube on that) next try to see if the bogging happens in the lower 1st and 2nd gears as well as the drive. And as for the fuel smell ur running way to rich if it's in oil and peel behind u can smell it. Could b as simple as faulty injectors all the way to bad rubber mounts knocking ur timing around so deff have a capable mechanic look at that for u. I'd also replace any and all sensors ur able to especially the idler control sensor and sensors for speed in the tranny
 
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