1UZ-FE 92' SC 400 NO SPARK and not turning on after changing (almost) EVERYTHING.
#1
1st Gear
Thread Starter
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Hi All,
I am very lost atm... These issues started when I was at the gas station after being on E for some time on the highway. When I pulled into the lane I noticed the battery light and red oil pan light come on and after filling up it did not start up (Very embarrassing situation overall). This lead me to change the 2 ignition coil packs, this worked for a while until I was going to class one day and my SC stopped unexpectedly on the highway and would not start up for me to get out of the way. I was towed off to another location later, but after sitting for a bit it turned on! I was not sure what the issue was there but I was able to drive home but it ran very sluggish, almost like it was on the verge of stalling and felt like the transmission was slipping ( it's an automatic btw), as if the power was getting to the transmission to turn but not going to the wheels. Also I must note that after unplugging the wires that connect to the coils then plugging them back in, it turns on sometimes (~10% success rate). When it runs it's so smooth!
Since then I have a changed a list of parts over some months.
- Both camshaft positioning sensors
-Crankshaft positioning sensor
-Both ignitors
-Distributor caps and rotors
-2 Ignition coil packs (both left and right,) twice!
-Paid to rebuild ECM
-New fuel pump
-New EFI relay
-New spark plugs and wires
-Battery has been fully charged and has been tested to be functional
- The MAF shouldn't be a problem since I know it the car can run without it for some time (runs rich though)
- The IAC valve seems to be intact as I never have issues at idle or while driving.
What really bothers me is that it no longer stalls (Perhaps due to new main ECM and 12V mod), but when it turns on (when it wants it seems), I am able to drive it around, pretty hard too, but as soon as I get back home and try to turn it back on it will not start back up. Now this seems to be a pattern of it not wanting to turn on after it has heated up and ran for some time (this lead me to replace the crankshaft positioning sensor but yielded the same problems). When I go to turn it on after it ran for some time, it cranks and the starter engages but testing for spark from the coil shows that no spark is being produced (led me to change ignitors, no success either). I tried the fuel pump ECM (FP ECM) bypass (12V mod, and turns out FP ECM is OK) and still was unsuccessful (changed fuel pump as a result, no success). I changed the EFI relay also but did not work. I do have a Check engine light when it does turn on and also when the key is in the on position. I checked it in the past and it said it was the O2 sensors, I figured this would not be enough for the car to not start altogether so I am not worried about it currently. I just want to figure this out and every time it turns on I get false hope!!!
Right now my research into this issue lead me to believe
1. that my rebuilt ECM was probably not done well and I may need to test it somewhere
2. The green Ig2 circuit opening relay is not functioning
3. The main ECM harness is not good anymore (would there be a way to test this???)
4. Injectors or some fuel problem?
I hope someone can help me here as I fear I am running out of leads and I need my car to get to school.
I am very lost atm... These issues started when I was at the gas station after being on E for some time on the highway. When I pulled into the lane I noticed the battery light and red oil pan light come on and after filling up it did not start up (Very embarrassing situation overall). This lead me to change the 2 ignition coil packs, this worked for a while until I was going to class one day and my SC stopped unexpectedly on the highway and would not start up for me to get out of the way. I was towed off to another location later, but after sitting for a bit it turned on! I was not sure what the issue was there but I was able to drive home but it ran very sluggish, almost like it was on the verge of stalling and felt like the transmission was slipping ( it's an automatic btw), as if the power was getting to the transmission to turn but not going to the wheels. Also I must note that after unplugging the wires that connect to the coils then plugging them back in, it turns on sometimes (~10% success rate). When it runs it's so smooth!
Since then I have a changed a list of parts over some months.
- Both camshaft positioning sensors
-Crankshaft positioning sensor
-Both ignitors
-Distributor caps and rotors
-2 Ignition coil packs (both left and right,) twice!
-Paid to rebuild ECM
-New fuel pump
-New EFI relay
-New spark plugs and wires
-Battery has been fully charged and has been tested to be functional
- The MAF shouldn't be a problem since I know it the car can run without it for some time (runs rich though)
- The IAC valve seems to be intact as I never have issues at idle or while driving.
What really bothers me is that it no longer stalls (Perhaps due to new main ECM and 12V mod), but when it turns on (when it wants it seems), I am able to drive it around, pretty hard too, but as soon as I get back home and try to turn it back on it will not start back up. Now this seems to be a pattern of it not wanting to turn on after it has heated up and ran for some time (this lead me to replace the crankshaft positioning sensor but yielded the same problems). When I go to turn it on after it ran for some time, it cranks and the starter engages but testing for spark from the coil shows that no spark is being produced (led me to change ignitors, no success either). I tried the fuel pump ECM (FP ECM) bypass (12V mod, and turns out FP ECM is OK) and still was unsuccessful (changed fuel pump as a result, no success). I changed the EFI relay also but did not work. I do have a Check engine light when it does turn on and also when the key is in the on position. I checked it in the past and it said it was the O2 sensors, I figured this would not be enough for the car to not start altogether so I am not worried about it currently. I just want to figure this out and every time it turns on I get false hope!!!
Right now my research into this issue lead me to believe
1. that my rebuilt ECM was probably not done well and I may need to test it somewhere
2. The green Ig2 circuit opening relay is not functioning
3. The main ECM harness is not good anymore (would there be a way to test this???)
4. Injectors or some fuel problem?
I hope someone can help me here as I fear I am running out of leads and I need my car to get to school.
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2KLS4CPLAT (03-05-23)