The factory shop manual doesn't have a good pinout for the ignition switch. I included the above diagram in post #8 to indicate that the ignition switch powers the CCCI fuse which is where the Ignition Module gets its power from the ignition switch. I put together a chart from wiring diagrams a while back which is pasted below as well as the shop manual page indicating most of the terminals connected to the ignition switch FWIW.
No start condition need help
- Thread starter 87chrisss
- Start date
The factory shop manual doesn't have a good pinout for the ignition switch. I included the above diagram in post #8 to indicate that the ignition switch powers the CCCI fuse which is where the Ignition Module gets its power from the ignition switch. I put together a chart from wiring diagrams a while back which is pasted below as well as the shop manual page indicating most of the terminals connected to the ignition switch FWIW.
Awesome!
Well swapped out the ignition switch still no spark, checked pin M while cranking 10+ volts and blue wire as well, unplugged and ugged fuel inj harness anything else i should try?
I moved the cam an inch to both directions nada..
One thing i noticed was that when i would turn the engine over sm showed 0 rpms , last but not least i felt the ECM warm? Anyone have any other suggestions i even unplugged all gauges possible bad ground? The new engine came black nt sure if it might have bad ground on rear pass head.
Any input would be great,
I moved the cam an inch to both directions nada..
One thing i noticed was that when i would turn the engine over sm showed 0 rpms , last but not least i felt the ECM warm? Anyone have any other suggestions i even unplugged all gauges possible bad ground? The new engine came black nt sure if it might have bad ground on rear pass head.
Any input would be great,
twin 93 svt
Member
- Joined
- Jan 23, 2002
trouble shot a similar problem, that ended up being loose ground off of back of the head.
Just found a thread back a few yrs back and i mean\ way back about this same car not having spark but inj pulse lol, dont think its the grounds for sure the wire harness is shit. Guess im going to have to remove the whole wire harness and run wires back to ecm,
This car keeps getting better, The funny thing is the guy told me it ran great no issues lol. From what it seems he bought it non running, then couldn't figure it out, and let it sit a few yrs and woke up one day and decided to sell the car.. then i came around and put it together. I should have checked th whole harness when i had the motor out.
MO
This car keeps getting better, The funny thing is the guy told me it ran great no issues lol. From what it seems he bought it non running, then couldn't figure it out, and let it sit a few yrs and woke up one day and decided to sell the car.. then i came around and put it together. I should have checked th whole harness when i had the motor out.
MO
- Joined
- Feb 18, 2006
Did you check the ecm plug for corrosion?
Yes i did, all seems corrosion free all pins look good,
- Rick no RPM's present when im turning the engine over on SM, - that would point to crank sensor BUT.. if im getting voltage @ the ICM from Crank sensor than the issue is from ICM to ECM.. Not crank sensor to ICM? Or how does information travel how does the car communicate thats were im puzzled?? Once info gets to ICM then it relays the info back to ECM and ECM syncs cam and crank right?
I have Tach/boost rdg on dash but not on scanmaster.... So... ICM isnt communicating back correctly to ECM
i have injector pulse, crank sensor is good
- Joined
- Feb 18, 2006
I do believe that's how it works. Have you ohm'd the wires from the icm to the ecm?
Rick
Rick
No i have not Ohmed anything i'll be honest im not an electrical wizard i can defend myself but im not too familiar with how to properly OHM a wire. I know that when we ohm the Plug wires we check for the resistance on that cable. BUT its incosistent depending on how long or how thick the cable is so i stay away from it.. I guess its time to learn..
Before i make a complete fool out of myself ohming wires.
Let me take a quick class online about Ohms and resistance/continuity and how to properly ohm a wire. Or at very least a tutorial
Before i make a complete fool out of myself ohming wires.
Let me take a quick class online about Ohms and resistance/continuity and how to properly ohm a wire. Or at very least a tutorial
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RmvBfrFlght
Well-Known Member
- Joined
- Sep 28, 2007
Refer to the diagram that TurboBuRick posted right above this post.
During cranking the ECM holds the BYPASS line at 0 volts (ECM pin D5). This tells the ICM to handle spark timing on it's own, along with the ICM clamping the EST line from the ECM low. This clamping is part of the code 42 testing.
The EST line is the spark control (dwell and timing) from the ECM. With a running engine the ECM uses this line to control the ICM.
Back to cranking, once the ICM 'sees' and sync's up to the cam sensor signal, it will then send reference pulses (DRPs) to the ECM. This is Ref Hi on ECM pin B5. Ref Lo on ECM pin B3 is a ground that originates at the ICM.
Now that the ECM is getting DRPs from the ICM it will start to fire the injectors in batch mode (all 6 together).
***You state that the injectors are firing, this shows that the ICM is getting both the crank & cam signal and is sending DRPs to the ECM. Without spark this will also flood the engine and fuel foul the spark plugs. Are the plugs fuel fouled?***
During cranking the firing of the spark plugs is on the ICM. However, if the ECM isn't holding the BYPASS low, then it is up to the ECM to toggle the EST line for the ICM to spark the plugs. Which it should be doing even during cranking.
Measure the voltage on ECM pin D5 at key-on, engine-off, it should be close to 0 volts. If not, then the ECM has an issue.
Can also pop ECM pin D5 out of the connector and see if there is spark. An open BYPASS line forces the spark timing onto the ICM. Takes the ECM out of the spark equation.
RemoveBeforeFlight
During cranking the ECM holds the BYPASS line at 0 volts (ECM pin D5). This tells the ICM to handle spark timing on it's own, along with the ICM clamping the EST line from the ECM low. This clamping is part of the code 42 testing.
The EST line is the spark control (dwell and timing) from the ECM. With a running engine the ECM uses this line to control the ICM.
Back to cranking, once the ICM 'sees' and sync's up to the cam sensor signal, it will then send reference pulses (DRPs) to the ECM. This is Ref Hi on ECM pin B5. Ref Lo on ECM pin B3 is a ground that originates at the ICM.
Now that the ECM is getting DRPs from the ICM it will start to fire the injectors in batch mode (all 6 together).
***You state that the injectors are firing, this shows that the ICM is getting both the crank & cam signal and is sending DRPs to the ECM. Without spark this will also flood the engine and fuel foul the spark plugs. Are the plugs fuel fouled?***
During cranking the firing of the spark plugs is on the ICM. However, if the ECM isn't holding the BYPASS low, then it is up to the ECM to toggle the EST line for the ICM to spark the plugs. Which it should be doing even during cranking.
Measure the voltage on ECM pin D5 at key-on, engine-off, it should be close to 0 volts. If not, then the ECM has an issue.
Can also pop ECM pin D5 out of the connector and see if there is spark. An open BYPASS line forces the spark timing onto the ICM. Takes the ECM out of the spark equation.
RemoveBeforeFlight
turbo96max
Member
- Joined
- Jun 6, 2007
Yo im off today.if you need a hand lmk.
Posted from the TurboBuick.Com mobile app
Posted from the TurboBuick.Com mobile app
Checked voltage, KEY ON ECM pin D5 had about .14 volts not 0, I also check hi and lo ref in cam and crank everything in range nothing is out of wack. i did feel the ECM get warm to the touch again though..
I also removed ECM pin D5 out of the connector still no spark.
A few of the ECM wiring colors are miscolored per the vortex buick ecm wiring.
Last but not least this car is a canadian ttype not sure if that has anything to do with it i doubt it just throwing a feeler..
I removed Knock sensor gauge i removed all the gauges from the car to rule out a faulty connection anywhere else i should look?
I installed SM still no RPM rdgs while turning over but injector pulse is fine.
I went back and read through the posts and didn't see where you tried using a known good coil. Are you confident the connections from the ignition module are solid? Sorry if I missed it. I also noticed an issue with the ECM chart showing that you should have 4.5 Volts on D5 with the key on. I went out to my car and checked this and as you have found and RmvBfrFlght indicated the voltage should actually be very near 0, mine was 17mV.
Its not the ICM/Coil Pack.. i have intermittent spark whenever it decides it wants to throw spark it does, i have injector pulse i have changed the crank sensor for a known good one 2 different times, i have injector pulse so crank sensor is working.
I have swapped ECM two times. and verified that both are working on my other car.
I swapped out the ICM twice and tested the ICM with my other car within minutes. Veriried GOOD.
Changed Cam sensor twice, even swapped caps, verified cam sensor is working with cam sensor tool.
Checked all grounds yesterday all fuses are good replaced ignition switch, verified power at ccci which sends voltage to coils.
Checked verified ALL pin's on ECM with Vortex Buicks ECM wiring print out and checked voltage key on and also engine off and under load when car is turning over.
Checked all pins on female icm bulkhead all female slots look good / checked Fuel inj harness all good.
I removed ALL gauges from inside the car also removed the knock sensor and removed splice ESC splice on ECM i did not have to do this but i did to rule any bad contact or connection.
I re-wired the stock oil pressure sensor since it had been cut off and replaced with a gauge, thought why not lets re-wire and check. Still nothing..
I then began to try and test something new, remove sensors one by one to see if by any chance i would get spark.. i removed the maf pipe, IAT MAF Sensor Then Fan Plug and turned it over she had spark on the tester but then went away? lol this effin car man..
Could not get it to throw spark again though. =/
Checked for stock theft deterrent but doesn't have.. It's has to be some BS , i removed most of the harness from the front, and im untapping all wires and re-taping them just to check all connections and wires.
Nightmare
I have swapped ECM two times. and verified that both are working on my other car.
I swapped out the ICM twice and tested the ICM with my other car within minutes. Veriried GOOD.
Changed Cam sensor twice, even swapped caps, verified cam sensor is working with cam sensor tool.
Checked all grounds yesterday all fuses are good replaced ignition switch, verified power at ccci which sends voltage to coils.
Checked verified ALL pin's on ECM with Vortex Buicks ECM wiring print out and checked voltage key on and also engine off and under load when car is turning over.
Checked all pins on female icm bulkhead all female slots look good / checked Fuel inj harness all good.
I removed ALL gauges from inside the car also removed the knock sensor and removed splice ESC splice on ECM i did not have to do this but i did to rule any bad contact or connection.
I re-wired the stock oil pressure sensor since it had been cut off and replaced with a gauge, thought why not lets re-wire and check. Still nothing..
I then began to try and test something new, remove sensors one by one to see if by any chance i would get spark.. i removed the maf pipe, IAT MAF Sensor Then Fan Plug and turned it over she had spark on the tester but then went away? lol this effin car man..
Could not get it to throw spark again though. =/
Checked for stock theft deterrent but doesn't have.. It's has to be some BS , i removed most of the harness from the front, and im untapping all wires and re-taping them just to check all connections and wires.
Nightmare
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AC delco i highly doubt its a maf issue, no mal codes on SM and no RPM rdg on SM but i do have tach rdg on dash
RmvBfrFlght
Well-Known Member
- Joined
- Sep 28, 2007
I think that it is normal to get no SM RPM reading while cranking. IIRC, the ECM doesn't do the RPM calculation unless the engine is running.
The tach on the dash gets it's information as a pulse stream directly from the ICM. Which is nearly the same signal as Ref Hi going to the ECM.
I'm beginning to wonder if the real issue is the IGN+ feed to pin P on the ICM. That it is bad and pin M is back feeding the ICM just enough for it to run but not properly fire the coils.
RemoveBeforeFlight
The tach on the dash gets it's information as a pulse stream directly from the ICM. Which is nearly the same signal as Ref Hi going to the ECM.
I'm beginning to wonder if the real issue is the IGN+ feed to pin P on the ICM. That it is bad and pin M is back feeding the ICM just enough for it to run but not properly fire the coils.
RemoveBeforeFlight
