1993 G-20 ECM information
GA van guy
10-15-2007, 11:23 PM
Hi, new poster, lurker for a while...
I am having drive-ability problems and emission problems with my 1993 G-20. Engine is 5.7 with TBI and full accessories.
From past experience with different equipment, I have learned to not take things for granted... And since I am not the first owner, I thought I would do some part number referencing...
Is there a place I can verify the correct ECM module part # for a vehicle? One dealerships in town referenced it from the VIN#, said they have a part available, but will not give me a number... the local auto supplies have half a dozen part #'s for that year/make/model...
Is this a common problem getting part #'s???
Anyone know a way to reference an ECM module part #?
THX in advance for any help!!!
I am having drive-ability problems and emission problems with my 1993 G-20. Engine is 5.7 with TBI and full accessories.
From past experience with different equipment, I have learned to not take things for granted... And since I am not the first owner, I thought I would do some part number referencing...
Is there a place I can verify the correct ECM module part # for a vehicle? One dealerships in town referenced it from the VIN#, said they have a part available, but will not give me a number... the local auto supplies have half a dozen part #'s for that year/make/model...
Is this a common problem getting part #'s???
Anyone know a way to reference an ECM module part #?
THX in advance for any help!!!
GA van guy
10-16-2007, 09:31 AM
Update:
I spoke with a Chevy dealership that would help! They confirmed the part # of the computer in the van, so it is the correct one... (not sure if it is working properly, but at lease I do know the part # is a good one if I go to replace it).
Here is the problem I am having; Vehicle blows black (not blue or white) smoke in varying amounts almost all the time. Fuel mileage is around 7-8 mpg. Note that this vehicle is used commercially for HVAC repair and is carrying probably close to 2000# of tools and parts.
Things that have been done:
*Plugs/wires/cap/rotor/coil
*Set timing to factory specs per vehicle label (0 D-TDC at idle with brown wire to dist disconnected)
*Air filter/PCV filter
*O2 sensor
*MAP sensor
*EGR valve and EGR valve vacuum valve (electric vacuum valve that mounts next to the MAP sensor)
*EECS fume canister
*Rebuild throttle body (was dirty inside due to bad gas)
*Scratch my head and fuss at it... this did not help much but it made me feel better... :nono:
I am going to do a compression check in a few minutes this morning to see if perhaps one or more of the cylinders is weak (rings, valves, etc???). I will post the results later.
THX for any input anyone has, this is really stumping me...
I spoke with a Chevy dealership that would help! They confirmed the part # of the computer in the van, so it is the correct one... (not sure if it is working properly, but at lease I do know the part # is a good one if I go to replace it).
Here is the problem I am having; Vehicle blows black (not blue or white) smoke in varying amounts almost all the time. Fuel mileage is around 7-8 mpg. Note that this vehicle is used commercially for HVAC repair and is carrying probably close to 2000# of tools and parts.
Things that have been done:
*Plugs/wires/cap/rotor/coil
*Set timing to factory specs per vehicle label (0 D-TDC at idle with brown wire to dist disconnected)
*Air filter/PCV filter
*O2 sensor
*MAP sensor
*EGR valve and EGR valve vacuum valve (electric vacuum valve that mounts next to the MAP sensor)
*EECS fume canister
*Rebuild throttle body (was dirty inside due to bad gas)
*Scratch my head and fuss at it... this did not help much but it made me feel better... :nono:
I am going to do a compression check in a few minutes this morning to see if perhaps one or more of the cylinders is weak (rings, valves, etc???). I will post the results later.
THX for any input anyone has, this is really stumping me...
MT-2500
10-16-2007, 11:11 AM
What engine and engine code?
Any codes in computer?
Any codes in computer?
GA van guy
10-16-2007, 12:50 PM
What engine and engine code?
Any codes in computer?
THX for your response MT-2500!!!
Whoops, my mistake... :disappoin
5.7 with TBI
Vehicle has front/rear A/C and overdrive tranny with lock-up torque converter.
Not sure where to find the engine code??? If you can tell me where to look, I will get it for you.
No codes in computer other than when I had the brown wire pulled to check timing. But I did have the battery disconnected a while back so I may have erased some codes... driving should set some codes if they are relevant.
I did the compression check and the worst cylinder is about 120#... the best was about 130#... so it appears there is not a 'bad cylinder'. What is interesting is that the low cylinder was #5, while the best cyulinder was #8...
The plugs were all sooty with a little hint of light chocolate on the insulator... seems to me that when it is running correctly it is close to right... but when it is running rich it is waaaay rich.
I am about to go get a throttle position sensor and try that... my reasoning at the moment leans that way.
Is there a test (that I can do) to verify if the computer is not functioning correctly (or intermittently)?
THX for your response, I really appreciate it!
Any codes in computer?
THX for your response MT-2500!!!
Whoops, my mistake... :disappoin
5.7 with TBI
Vehicle has front/rear A/C and overdrive tranny with lock-up torque converter.
Not sure where to find the engine code??? If you can tell me where to look, I will get it for you.
No codes in computer other than when I had the brown wire pulled to check timing. But I did have the battery disconnected a while back so I may have erased some codes... driving should set some codes if they are relevant.
I did the compression check and the worst cylinder is about 120#... the best was about 130#... so it appears there is not a 'bad cylinder'. What is interesting is that the low cylinder was #5, while the best cyulinder was #8...
The plugs were all sooty with a little hint of light chocolate on the insulator... seems to me that when it is running correctly it is close to right... but when it is running rich it is waaaay rich.
I am about to go get a throttle position sensor and try that... my reasoning at the moment leans that way.
Is there a test (that I can do) to verify if the computer is not functioning correctly (or intermittently)?
THX for your response, I really appreciate it!
MT-2500
10-17-2007, 09:25 AM
THX for your response MT-2500!!!
Whoops, my mistake... :disappoin
5.7 with TBI
Vehicle has front/rear A/C and overdrive tranny with lock-up torque converter.
Not sure where to find the engine code??? If you can tell me where to look, I will get it for you.
No codes in computer other than when I had the brown wire pulled to check timing. But I did have the battery disconnected a while back so I may have erased some codes... driving should set some codes if they are relevant.
I did the compression check and the worst cylinder is about 120#... the best was about 130#... so it appears there is not a 'bad cylinder'. What is interesting is that the low cylinder was #5, while the best cyulinder was #8...
The plugs were all sooty with a little hint of light chocolate on the insulator... seems to me that when it is running correctly it is close to right... but when it is running rich it is waaaay rich.
I am about to go get a throttle position sensor and try that... my reasoning at the moment leans that way.
Is there a test (that I can do) to verify if the computer is not functioning correctly (or intermittently)?
THX for your response, I really appreciate it!
Your best deal is to get it on a engine capable scanner and read out all data in the computer.
The scanner has a lot of information on how it is running and tells what all sensors are doing and reads out fuel mix and a lot of other stuff.
On them years also check base timing and check dist shaft for wear and egr valve operation and test fuel pressure.
Whoops, my mistake... :disappoin
5.7 with TBI
Vehicle has front/rear A/C and overdrive tranny with lock-up torque converter.
Not sure where to find the engine code??? If you can tell me where to look, I will get it for you.
No codes in computer other than when I had the brown wire pulled to check timing. But I did have the battery disconnected a while back so I may have erased some codes... driving should set some codes if they are relevant.
I did the compression check and the worst cylinder is about 120#... the best was about 130#... so it appears there is not a 'bad cylinder'. What is interesting is that the low cylinder was #5, while the best cyulinder was #8...
The plugs were all sooty with a little hint of light chocolate on the insulator... seems to me that when it is running correctly it is close to right... but when it is running rich it is waaaay rich.
I am about to go get a throttle position sensor and try that... my reasoning at the moment leans that way.
Is there a test (that I can do) to verify if the computer is not functioning correctly (or intermittently)?
THX for your response, I really appreciate it!
Your best deal is to get it on a engine capable scanner and read out all data in the computer.
The scanner has a lot of information on how it is running and tells what all sensors are doing and reads out fuel mix and a lot of other stuff.
On them years also check base timing and check dist shaft for wear and egr valve operation and test fuel pressure.
GA van guy
10-17-2007, 10:44 AM
Your best deal is to get it on a engine capable scanner and read out all data in the computer.
The scanner has a lot of information on how it is running and tells what all sensors are doing and reads out fuel mix and a lot of other stuff.
On them years also check base timing and check dist shaft for wear and egr valve operation and test fuel pressure.
That is a wise suggestion, THX for mentioning it! I think I know someone that has one that will access an OBD-1 system at that depth.
I did replace the TPS (throttle position sensor) yesterday, that did help.
The main issue now is that when the vehicle comes to a dead stop in gear (normal driving); the engine changes from running relatively smooth with little if any smoke>>>it drops about a hundred RPM into what appears to be idle mode. In this mode the engine starts missing and shaking, and the black smoke starts again. If I stay in this place long enough the IAC motor starts 'hunting' and eventually the engine dies. But if I just accelerate off from a light it will keep smoking. However, if I carefully raise the engine about 200-300 RPM and hold it there for 4-5 seconds the computer seems to 'clear'... the result is the engine smooths out and the black smoke goes away. One other thing is that regardless of any other factors; if I really put my foot into the gas, you will get a HUGE cloud of really sooty black smoke. Note that as far as I can tell, ther is no blue or white smoke at all. The engine does use about 3/4 qt of oil between changes (3500 miles).
My gut says that there is a vacuum leak somewhere... That is today's project (vacuum).
THX again for your help. I have learned an immense amount about how to work with computer driven engines through this mess.
The scanner has a lot of information on how it is running and tells what all sensors are doing and reads out fuel mix and a lot of other stuff.
On them years also check base timing and check dist shaft for wear and egr valve operation and test fuel pressure.
That is a wise suggestion, THX for mentioning it! I think I know someone that has one that will access an OBD-1 system at that depth.
I did replace the TPS (throttle position sensor) yesterday, that did help.
The main issue now is that when the vehicle comes to a dead stop in gear (normal driving); the engine changes from running relatively smooth with little if any smoke>>>it drops about a hundred RPM into what appears to be idle mode. In this mode the engine starts missing and shaking, and the black smoke starts again. If I stay in this place long enough the IAC motor starts 'hunting' and eventually the engine dies. But if I just accelerate off from a light it will keep smoking. However, if I carefully raise the engine about 200-300 RPM and hold it there for 4-5 seconds the computer seems to 'clear'... the result is the engine smooths out and the black smoke goes away. One other thing is that regardless of any other factors; if I really put my foot into the gas, you will get a HUGE cloud of really sooty black smoke. Note that as far as I can tell, ther is no blue or white smoke at all. The engine does use about 3/4 qt of oil between changes (3500 miles).
My gut says that there is a vacuum leak somewhere... That is today's project (vacuum).
THX again for your help. I have learned an immense amount about how to work with computer driven engines through this mess.
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