Worked on O2 sensors, now won't start
04-26-2012, 12:04 PM
#1
Worked on O2 sensors, now won't start
Hi all
I have owned my 91 ZR1 since 93. Today I decided to cut some
solder splices from an extension added to the right side O2 sensor wires many years ago.
I had added 18 inches or so to the sensor wires in order to rerout the wires around the headers
I installed back then. The solder had corroded green underneath the heatshrink and began to
crumble. My plan was to cut them out and replace with crimp splices. I read somewhere that
solder does not work well with O2 sensors.
In any case, the car started as normal, I drove it onto my ramps, shut off the ignition and went to bed. Next day (today) I slid under, cut out two of the six splices and then remembered I had not
disconnected the battery. I unhooked the negative post and then completed my splice replacements.
When I went to start car to remove it from the ramp the starter engaged as normal but no
start. Starter tuning engine but will not fire.
Since then I have checked: ECM shows 12s only no other codes, CCM codes C12 only (good?), no CCM ERR message, spark is good, added 5 gallons fuel, all fuses in main and aux panels good,
replaced the MEMCAL chip with a spare that was working when I took it out, and charged battery.
On each start I can hear fuel pump run for 2 seconds so I assume FP relay OK. Both FPs and all
FP and tank system filters were changed last fall. I removed schrader valve cap and pushed
valve release while son cranked the starter. A small amount (half teaspoon) of fuel dribbled out without much force. Attached fuel pressure guage and it reads zero PSI while cranking.
Sounds like a fuel issue. Here are my questions:
Could clipping 2 O2 sensor wires with key removed but battery attached cause this
or is it just a coincidental failure?
If I can hear the fuel pump run for 2 secs how can the fuel pressure be zero, assuming
my test guage is working properly. After many start attempts today I never smelled any fuel
in the engine compartment or anywhere else.
If I mucked up the resplicing somehow wouldn't the car at least start? O2 not part
of start (open loop) parameters until idle (closed loop) if I remember right. The car
should start even if they are unplugged.
Remember the car started perfectly prior to my rewire project. It really seems that
something I did caused the no start. I just can't figure out what it is.
Thanks for any help. Unfortunately I do not have a scan tool.
Neil in Ft. Walton, FL
I have owned my 91 ZR1 since 93. Today I decided to cut some
solder splices from an extension added to the right side O2 sensor wires many years ago.
I had added 18 inches or so to the sensor wires in order to rerout the wires around the headers
I installed back then. The solder had corroded green underneath the heatshrink and began to
crumble. My plan was to cut them out and replace with crimp splices. I read somewhere that
solder does not work well with O2 sensors.
In any case, the car started as normal, I drove it onto my ramps, shut off the ignition and went to bed. Next day (today) I slid under, cut out two of the six splices and then remembered I had not
disconnected the battery. I unhooked the negative post and then completed my splice replacements.
When I went to start car to remove it from the ramp the starter engaged as normal but no
start. Starter tuning engine but will not fire.
Since then I have checked: ECM shows 12s only no other codes, CCM codes C12 only (good?), no CCM ERR message, spark is good, added 5 gallons fuel, all fuses in main and aux panels good,
replaced the MEMCAL chip with a spare that was working when I took it out, and charged battery.
On each start I can hear fuel pump run for 2 seconds so I assume FP relay OK. Both FPs and all
FP and tank system filters were changed last fall. I removed schrader valve cap and pushed
valve release while son cranked the starter. A small amount (half teaspoon) of fuel dribbled out without much force. Attached fuel pressure guage and it reads zero PSI while cranking.
Sounds like a fuel issue. Here are my questions:
Could clipping 2 O2 sensor wires with key removed but battery attached cause this
or is it just a coincidental failure?
If I can hear the fuel pump run for 2 secs how can the fuel pressure be zero, assuming
my test guage is working properly. After many start attempts today I never smelled any fuel
in the engine compartment or anywhere else.
If I mucked up the resplicing somehow wouldn't the car at least start? O2 not part
of start (open loop) parameters until idle (closed loop) if I remember right. The car
should start even if they are unplugged.
Remember the car started perfectly prior to my rewire project. It really seems that
something I did caused the no start. I just can't figure out what it is.
Thanks for any help. Unfortunately I do not have a scan tool.
Neil in Ft. Walton, FL
04-26-2012, 03:21 PM
#2
Team Owner
No idea if your issue is related to the 02 sensor, but the right way to add length, is to make an extension using a male on one end and a female on the other. Solder will not adhere well to the 02 wire, and splicing can change the value resistance of the wire, which will send the wrong info to your ecm.
04-26-2012, 05:47 PM
#3
Burning Brakes
Neil,
Go here for advice: http://www.zr1.net/forum/index.php
Both pumps run at initial start then secondary fuel pump shuts off. The folks over at the other site will help.
Sounds like primary pump may have failed.
Ted
Go here for advice: http://www.zr1.net/forum/index.php
Both pumps run at initial start then secondary fuel pump shuts off. The folks over at the other site will help.
Sounds like primary pump may have failed.
Ted
04-26-2012, 10:30 PM
#4
No idea if your issue is related to the 02 sensor, but the right way to add length, is to make an extension using a male on one end and a female on the other. Solder will not adhere well to the 02 wire, and splicing can change the value resistance of the wire, which will send the wrong info to your ecm.
headers on the vette it was much harder to get that info. My plan
was to swap over to crimp connectors and see if the car idled better.
I read crimps were OK for O2 sensors.
I will remake the entire connector when all issues are resolved.
Right now the car won't even start so that is the primary problem
at the moment.
Thanks
