Greatfurry1
Newbie
Hi - new to this forum and to GMT 400s - vehicle is a 1994 C1500 std.cab, 4.3LV6, Auto, 214Kmiles
I recently picked up this old and well-used construction company truck - just for something interesting to work on....ran fair when I got it, but not great: lethargic, slow acceleration, felt like it would stall when taking your foot off the gas and it was shifting to idle, rough transmission shifting (especially first to second), and a Service Engine Soon light came and went.
I've been doing normal basic maintenance someone might do for a truck over 200K miles -
- new tires, new plugs, wires, cap/rotor/coil/TPS/Idle Air valve/EGR solenoid/MAP sensor, PCV, gas cap and radiator cap/ fuel pump relay/ oil change, new battery, clean and tighten engine grounds (fixed the Service Engine light issue), Seafoam the intake, fuel system, and through the oil, replaced the fuel injectors and the distributor...plus some other things I can't remember. The engine is not burning or losing oil - and the major liquids are new and quite clean (oil/transmission/coolant).
Runs nice now, starts instantly and accelerates great, drives nicely, but feels like it is missing a bit - have not yet checked the timing. My first Chevy truck (I've owned only Fords) - it is a fairly well-built truck IMO - but God almighty - I so wish Chevy hadn't located the distributor for this engine way in the back next to the firewall (most Ford distributors are in front!)
My questions -
1. According to most literature, this engine has two knock sensors, one in the rear under the distributor and one on one of the engine banks. OK, bought a new sensor and tried to change it while replacing the distributor (rear of the engine) but pulling the connector, find that it is completely different than the new part - and I have double and triple checked the correct part visually, which is supposed to have only a round, single wire connection. The currently installed part has a three pin receiver plug (seems very similar to the TPS connector) - completely different in that respect, but otherwise closely resembles the overall knock sensor in physical appearance. I've looked around quite a bit on the web and can find nothing to indicate why the sensor connection is so different....or for that matter, what sensor I could/should buy to replace the existing one. The second knock sensor on the engine block does have the single connector as it is supposed to, but it is rusted in place (more later)
2. I've had a similar problem with the coolant temperature sensor at the front of the engine block (which I targeted because the temp gauge was reading quite low in my opinion -never above 180 -200 degrees in mid July!) - when I removed the existing sensor (PIA!), it had two connection pins, one oriented horizontally and one vertically, while the replacement has two vertical pins. Huh? So, so far, haven't replaced it yet.
3. General issue - I live in central Massachusetts, so a fair amount of rust is around and it has had a very negative affect on the removal process for some parts and sensors. For example, I have been unable to replace the EGR, the oxygen sensor, and the second knock sensor - they are simply rusted in place and do not respond to multiple tapping and PBlaster or Liquid Wrench applications.
I have not 'used the bigger hammer' philosophy (just simply apply more and more muscle), especially to the EGR bolt, for fear of breaking off the bolt or sensor in question and creating a whole new and costly nightmare.
Any thoughts on the above are welcome and certainly appreciated.
Thank you.
I recently picked up this old and well-used construction company truck - just for something interesting to work on....ran fair when I got it, but not great: lethargic, slow acceleration, felt like it would stall when taking your foot off the gas and it was shifting to idle, rough transmission shifting (especially first to second), and a Service Engine Soon light came and went.
I've been doing normal basic maintenance someone might do for a truck over 200K miles -
- new tires, new plugs, wires, cap/rotor/coil/TPS/Idle Air valve/EGR solenoid/MAP sensor, PCV, gas cap and radiator cap/ fuel pump relay/ oil change, new battery, clean and tighten engine grounds (fixed the Service Engine light issue), Seafoam the intake, fuel system, and through the oil, replaced the fuel injectors and the distributor...plus some other things I can't remember. The engine is not burning or losing oil - and the major liquids are new and quite clean (oil/transmission/coolant).
Runs nice now, starts instantly and accelerates great, drives nicely, but feels like it is missing a bit - have not yet checked the timing. My first Chevy truck (I've owned only Fords) - it is a fairly well-built truck IMO - but God almighty - I so wish Chevy hadn't located the distributor for this engine way in the back next to the firewall (most Ford distributors are in front!)
My questions -
1. According to most literature, this engine has two knock sensors, one in the rear under the distributor and one on one of the engine banks. OK, bought a new sensor and tried to change it while replacing the distributor (rear of the engine) but pulling the connector, find that it is completely different than the new part - and I have double and triple checked the correct part visually, which is supposed to have only a round, single wire connection. The currently installed part has a three pin receiver plug (seems very similar to the TPS connector) - completely different in that respect, but otherwise closely resembles the overall knock sensor in physical appearance. I've looked around quite a bit on the web and can find nothing to indicate why the sensor connection is so different....or for that matter, what sensor I could/should buy to replace the existing one. The second knock sensor on the engine block does have the single connector as it is supposed to, but it is rusted in place (more later)
2. I've had a similar problem with the coolant temperature sensor at the front of the engine block (which I targeted because the temp gauge was reading quite low in my opinion -never above 180 -200 degrees in mid July!) - when I removed the existing sensor (PIA!), it had two connection pins, one oriented horizontally and one vertically, while the replacement has two vertical pins. Huh? So, so far, haven't replaced it yet.
3. General issue - I live in central Massachusetts, so a fair amount of rust is around and it has had a very negative affect on the removal process for some parts and sensors. For example, I have been unable to replace the EGR, the oxygen sensor, and the second knock sensor - they are simply rusted in place and do not respond to multiple tapping and PBlaster or Liquid Wrench applications.
I have not 'used the bigger hammer' philosophy (just simply apply more and more muscle), especially to the EGR bolt, for fear of breaking off the bolt or sensor in question and creating a whole new and costly nightmare.
Any thoughts on the above are welcome and certainly appreciated.
Thank you.
