wont start [no spark] HELP
- Thread starter crazygn
- Start date
- Joined
- May 29, 2001
Code 23?? According to my 1984 manual, there ISN'T a code 23 for these cars!
I have a comprehensive manual of trouble codes for "GM computer command control 3.8L Port fuel injection"...it goes from code 22 (TPS) to code 24 (VSS), with NO code 23!
I have a manual of "GM computer command control theory and operation"...in a simple list of codes, it shows code 23 as "MAT sensor low", but later in the comprehensive version it shows code 23 as "M/C solenoid circuit low"--this is the Mixture Control solenoid on the CARBURETORS!
Houston, we have a problem?
I have a comprehensive manual of trouble codes for "GM computer command control 3.8L Port fuel injection"...it goes from code 22 (TPS) to code 24 (VSS), with NO code 23!
I have a manual of "GM computer command control theory and operation"...in a simple list of codes, it shows code 23 as "MAT sensor low", but later in the comprehensive version it shows code 23 as "M/C solenoid circuit low"--this is the Mixture Control solenoid on the CARBURETORS!
Houston, we have a problem?
- Joined
- May 29, 2001
Here's a test procedure I posted about a week ago...it's lengthy, but if all else fails, it may be worth your time! By the way, this is all taken from a GM troubleshooting flowchart that I just tried to translate here! I want to try & get a good scan of this flowchart and put in on the internet! Until then, here goes!
Below are links to repair manual pictures to reference from:
ECM Plug
Sensor Plug
You'll need to get at the ECM and the cam & crank sensors to do some voltage tests. If you have a NEEDLE type voltmeter, it may work better for these tests, as it will visibly "swing" when the sensor switches open & close (IF they're working okay!)
Here goes:
First, test your meter and ground! (see ECM Plug) Check connection A-6, "ign, ECM fuse" for 12 volts. (for ALL tests, BE SURE the negative lead of the voltmeter is connected to a GOOD GROUND!)
#1- (see ECM Plug) With the key off, disconnect the ECM A-B connector. With the positive lead of the voltmeter, probe the B-5 connection (highlighted yellow, this is the crank sensor signal) Crank the engine and watch the meter...you should have varying voltage from 1 to 7 volts.
If NOT okay, proceed to #2.
If you ARE seeing correct voltage, your cam & crank sensors are okay, and your coil and/or ignition module may be the problem! You need to loosen the coilpack, and check the BLUE wire for 12 volts, key on. If it DOES have 12 volts, then the problem is likely the ignition module.
#2- now probe the A-11 connection... (highlighted green, this is the cam sensor signal). Crank the engine...you should have varying voltage from 1 to 9 volts.
If it IS okay, THE CAM SENSOR IS FINE, AND YOU ONLY NEED TO TEST THE CRANK SENSOR IN ALL FURTHER TESTS!
If it's NOT okay, there's no cam sensor signal!
Plug the ECM connector back in, and head for the sensors!
#3 (see "Sensor Plug") Unplug the cam sensor plug. Turn the key "ON" ...On the MODULE SIDE of the plug, probe the "A" wire for voltage, after which probe the "B" wire for voltage. You should have between 5 and 11 volts on BOTH wires.
If you ARE seeing correct voltage, THEN: with the negative lead of the voltmeter, probe the "C" wire, and with the positive lead probe the "A" wire. You should have between 5 and 11 volts. Note the results, then REPEAT THIS TEST WITH THE CRANK SENSOR PLUG!
If ANY of the sensor plug tests FAILED, you have a probably ignition module problem...
If ALL the sensor plug tests PASSED, then PLUG IN the sensor plugs, and proceed:
#4. Test the cam sensor: Probe the "B" wire of the cam sensor, then crank the engine and watch the meter. You SHOULD have varying voltage between 1/2 and 9 volts. REPEAT THIS TEST WITH THE CRANK SENSOR!
If either sensor fails this test, then it's possible that sensor is bad! If they PASS this test, it's likely the ignition module, or the connections TO the ignition module are bad)
Hope this makes sense!
Below are links to repair manual pictures to reference from:
ECM Plug
Sensor Plug
You'll need to get at the ECM and the cam & crank sensors to do some voltage tests. If you have a NEEDLE type voltmeter, it may work better for these tests, as it will visibly "swing" when the sensor switches open & close (IF they're working okay!)
Here goes:
First, test your meter and ground! (see ECM Plug) Check connection A-6, "ign, ECM fuse" for 12 volts. (for ALL tests, BE SURE the negative lead of the voltmeter is connected to a GOOD GROUND!)
#1- (see ECM Plug) With the key off, disconnect the ECM A-B connector. With the positive lead of the voltmeter, probe the B-5 connection (highlighted yellow, this is the crank sensor signal) Crank the engine and watch the meter...you should have varying voltage from 1 to 7 volts.
If NOT okay, proceed to #2.
If you ARE seeing correct voltage, your cam & crank sensors are okay, and your coil and/or ignition module may be the problem! You need to loosen the coilpack, and check the BLUE wire for 12 volts, key on. If it DOES have 12 volts, then the problem is likely the ignition module.
#2- now probe the A-11 connection... (highlighted green, this is the cam sensor signal). Crank the engine...you should have varying voltage from 1 to 9 volts.
If it IS okay, THE CAM SENSOR IS FINE, AND YOU ONLY NEED TO TEST THE CRANK SENSOR IN ALL FURTHER TESTS!
If it's NOT okay, there's no cam sensor signal!
Plug the ECM connector back in, and head for the sensors!
#3 (see "Sensor Plug") Unplug the cam sensor plug. Turn the key "ON" ...On the MODULE SIDE of the plug, probe the "A" wire for voltage, after which probe the "B" wire for voltage. You should have between 5 and 11 volts on BOTH wires.
If you ARE seeing correct voltage, THEN: with the negative lead of the voltmeter, probe the "C" wire, and with the positive lead probe the "A" wire. You should have between 5 and 11 volts. Note the results, then REPEAT THIS TEST WITH THE CRANK SENSOR PLUG!
If ANY of the sensor plug tests FAILED, you have a probably ignition module problem...
If ALL the sensor plug tests PASSED, then PLUG IN the sensor plugs, and proceed:
#4. Test the cam sensor: Probe the "B" wire of the cam sensor, then crank the engine and watch the meter. You SHOULD have varying voltage between 1/2 and 9 volts. REPEAT THIS TEST WITH THE CRANK SENSOR!
If either sensor fails this test, then it's possible that sensor is bad! If they PASS this test, it's likely the ignition module, or the connections TO the ignition module are bad)
Hope this makes sense!
Two questions:
#1. How do you verify that you are getting gas ?
- odour on plugs ?
- wet wet wet plugs after cranking ?
#2. How old is the crank sensor on the motor ?
- brand new ?
- original ?
(Okay...three...I lied)
#3. What did you do with the injectors when they were out of the motor ?
- cleaned ?
- if so...were they oiled to keep from seizing ?
- if left for a couple of days or more with no fuel or machine oil to lube them - they WILL sieze.
I say try a NEW crank sensor, properly installed and gapped. The one you have now may LOOK fine but could be toast - MINE WAS. ALSO if you are uncertain (like I was) if you are getting gas - get a noid light and plug it into injector #1 (easiest to access) and have someone crank the motor over while you watch the noid light for flashes (injector pulses). That verifies the gas situation - providing your injectors are clean and not siezed like mine.
Rule out the easy stuff first then move on to the more complicated stuff. By the way - save that ECM plug pic - BFH posted it for me and it comes in handy ! I checked all my voltages to ensure all was where it was supposed to be. Might be something simple - and probably IS.
#1. How do you verify that you are getting gas ?
- odour on plugs ?
- wet wet wet plugs after cranking ?
#2. How old is the crank sensor on the motor ?
- brand new ?
- original ?
(Okay...three...I lied)
#3. What did you do with the injectors when they were out of the motor ?
- cleaned ?
- if so...were they oiled to keep from seizing ?
- if left for a couple of days or more with no fuel or machine oil to lube them - they WILL sieze.
I say try a NEW crank sensor, properly installed and gapped. The one you have now may LOOK fine but could be toast - MINE WAS. ALSO if you are uncertain (like I was) if you are getting gas - get a noid light and plug it into injector #1 (easiest to access) and have someone crank the motor over while you watch the noid light for flashes (injector pulses). That verifies the gas situation - providing your injectors are clean and not siezed like mine.
Rule out the easy stuff first then move on to the more complicated stuff. By the way - save that ECM plug pic - BFH posted it for me and it comes in handy ! I checked all my voltages to ensure all was where it was supposed to be. Might be something simple - and probably IS.
Ok guys this is what i got from buick from hell's test
had 12v at ecm fuse
had 9v at the crank signal b-5
had 12v at a-11 cam sensor signal
module side of the plug
crank sensor
9v at a
6v at -b
9v at a-c
cam sensor module plug
10v at -a
7v at -b
9.5v at a-c
ok now i check the sensor side plugs and i dont get it i try to prob b on the crank senor and turn the motor no volts, now i check the cam sensor plug the same way and nothing but when i tryed to check this one time the car tryed to start and fire off with the cam sensor not hooked up.
this is to crazy the name fits this car to well,crazygn
HELP
had 12v at ecm fuse
had 9v at the crank signal b-5
had 12v at a-11 cam sensor signal
module side of the plug
crank sensor
9v at a
6v at -b
9v at a-c
cam sensor module plug
10v at -a
7v at -b
9.5v at a-c
ok now i check the sensor side plugs and i dont get it i try to prob b on the crank senor and turn the motor no volts, now i check the cam sensor plug the same way and nothing but when i tryed to check this one time the car tryed to start and fire off with the cam sensor not hooked up.
this is to crazy the name fits this car to well,crazygn
HELP
Ok this is what i got from the test -i got volts to b-5 i got volts to a-11 . I got good volts from the module side plugs both cam and crank. then i checked the plugs on the cam and crank sensors and i get nothing on both , but this is what i dont get i unpluged the cam sensor to check it , i prob the b on the plug and have my wife turn the key and the car starts for a sec when i tryed it again no start this time .
what is going on this is crazy , maybe the car likes my wife and not me
what is going on this is crazy , maybe the car likes my wife and not me
D
dave84gn
Guest
Congrats man! Always good to hear.
Dave
Dave
