Wierd Ignition Issue- Need some help from the pros - TriStateTuners.com :: Home of Tristate Auto Enthusiast

su_maverick · 08-20-2007, 03:32 PM

I figured I would put this up in general automotive since I have it on motor specific boards elsewhere. I am having a very frustrating time trying to sort out an ignition problem with my car. I have a 1999 LS1 with a T56 in a 1995 RX7. I have everything hooked up but I cannot seem to get spark on my plugs. Here is some info on things that I have already checked.

- Compression numbers are all in the green. They are all between 205-225.
- I am registering 12V at the coil connectors with IGN on and during cranking
- The black wires on the coil connectors are properly grounded
- The harness is properly grounded
- The engine block is properly grounded
- The injectors are firing during cranking
- The crank position sensor is plugged in and there are no frayed wires
- I am registering 12V with the ignition off on Pins 20 & 57 (These are the 12V constant and 12V IGN On pins for the PCM)
- I am registering 12V on Pin 19 (Again, 12V IGN On Pin) during cranking
- The plugs will not fire if the MAF is plugged in or not
- I have fired up the motor before a couple months ago
- The battery is fully charged

Some info about my swap:

- I have no EGR or AIR system.
- The ECU has been tuned without the rear 02s as well as EGR, AIR & VATS
- I am running a stock LS1 with headers and an open air intake
- I am running NKG TR55 plugs with Magnecor wires on stock coils

So far it seems that it could only be 4 things (based on my limited knowledge)
- Bad Crank Position Sensor/Connector (most likely)
- Shot PCM (not sure, just a guess)
- Damaged Reluctor Wheel (nothing has happened to the engine since I last test fired it and it ran well so less likely)
- Too much movement in cranks (again, less likely since it cranks very smoothly with no vibration or abnormal noises)

Any help on figuring this out would be much appreciated as I want to drive my car before it starts getting crappy out.

Thanks!

sponsored1 · 08-21-2007, 12:27 AM

Your best bet is to check the codes, if the crank sensor goes bad there are 2 seperate codes for it. One indicates a wiring problem, and the other is if the actual sensor itself goes bad, or is incorrectly spaced to the reluctor wheel. Normally if the crank sensor goes bad, you will not have an rpm signal, and your injectors will not fire. Anyway scan the car and check for any codes.

su_maverick · 08-21-2007, 09:35 AM

So, if my injectors are firing/clicking, then my crank sensor is good?

08-20-2007, 03:32 PM	#1
su_maverick Tri-State Addict Join Date: Apr 2006 Location: Bergen Co. Member #1755 My Ride: 2001 Saturn SC1 iTrader: (0)	Wierd Ignition Issue- Need some help from the pros I figured I would put this up in general automotive since I have it on motor specific boards elsewhere. I am having a very frustrating time trying to sort out an ignition problem with my car. I have a 1999 LS1 with a T56 in a 1995 RX7. I have everything hooked up but I cannot seem to get spark on my plugs. Here is some info on things that I have already checked. - Compression numbers are all in the green. They are all between 205-225. - I am registering 12V at the coil connectors with IGN on and during cranking - The black wires on the coil connectors are properly grounded - The harness is properly grounded - The engine block is properly grounded - The injectors are firing during cranking - The crank position sensor is plugged in and there are no frayed wires - I am registering 12V with the ignition off on Pins 20 & 57 (These are the 12V constant and 12V IGN On pins for the PCM) - I am registering 12V on Pin 19 (Again, 12V IGN On Pin) during cranking - The plugs will not fire if the MAF is plugged in or not - I have fired up the motor before a couple months ago - The battery is fully charged Some info about my swap: - I have no EGR or AIR system. - The ECU has been tuned without the rear 02s as well as EGR, AIR & VATS - I am running a stock LS1 with headers and an open air intake - I am running NKG TR55 plugs with Magnecor wires on stock coils So far it seems that it could only be 4 things (based on my limited knowledge) - Bad Crank Position Sensor/Connector (most likely) - Shot PCM (not sure, just a guess) - Damaged Reluctor Wheel (nothing has happened to the engine since I last test fired it and it ran well so less likely) - Too much movement in cranks (again, less likely since it cranks very smoothly with no vibration or abnormal noises) Any help on figuring this out would be much appreciated as I want to drive my car before it starts getting crappy out. Thanks!

08-21-2007, 12:27 AM	#2
sponsored1 Tri-State Aficionado Join Date: Nov 2005 Location: Buckingham, Pa Member #1049 My Ride: POS with a diff and giant brakes iTrader: (2)	Your best bet is to check the codes, if the crank sensor goes bad there are 2 seperate codes for it. One indicates a wiring problem, and the other is if the actual sensor itself goes bad, or is incorrectly spaced to the reluctor wheel. Normally if the crank sensor goes bad, you will not have an rpm signal, and your injectors will not fire. Anyway scan the car and check for any codes. __________________ To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures. 1995 s10 1999 Svt Contour 1972 Bmw 2002 1978 Gs 1000, 2003 Gsxr 600

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08-21-2007, 09:35 AM	#3
su_maverick Tri-State Addict Join Date: Apr 2006 Location: Bergen Co. Member #1755 My Ride: 2001 Saturn SC1 iTrader: (0)	So, if my injectors are firing/clicking, then my crank sensor is good?