***No start/No Spark Ran Fine last Night***
03-28-2017, 08:21 PM
#32
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
So...
Fuel pressure is confirmed OK with a pressure gauge?
Then on to ignition, where we suspect that X is causing no spark. Actually a list of X's.
----
What was worked on last? That's often a good place to start if it's all all even remotely related to symptoms. The RL jury can help you decide what's related.
After that, it comes down to some basic electrical troubleshooting, either to make the fuel pressure come up, or get a spark. In either case, start at one end and work towards the other end of the system. Go from the "underperforming" end if you wish. I like to start in the middle of each system under question, halving the list of probable causes with each test. For the fuel system with no pressure for instance, I check to see if there's full voltage at the fuse with the key on and cranking. There's a tiny hole in the back of the fuses that will take a needle probe. Use that to test the circuits without disturbing anything. Test both sides of each fuse for voltage to ground. If voltage is low, work towards the battery. If voltage is OK, work towards the pump. If the relay doesn't pull in, troubleshoot back through the LH towards the EZF. Does the tach bounce as you crank on the starter? Bouncing suggests that the CPS is OK, no movement points to not. You get the idea. Diagnosing is the logical process of systematically eliminating things it might be. Each step narrows the remaining options by half if you do it right.
Fuel pressure is confirmed OK with a pressure gauge?
Then on to ignition, where we suspect that X is causing no spark. Actually a list of X's.
----
What was worked on last? That's often a good place to start if it's all all even remotely related to symptoms. The RL jury can help you decide what's related.
After that, it comes down to some basic electrical troubleshooting, either to make the fuel pressure come up, or get a spark. In either case, start at one end and work towards the other end of the system. Go from the "underperforming" end if you wish. I like to start in the middle of each system under question, halving the list of probable causes with each test. For the fuel system with no pressure for instance, I check to see if there's full voltage at the fuse with the key on and cranking. There's a tiny hole in the back of the fuses that will take a needle probe. Use that to test the circuits without disturbing anything. Test both sides of each fuse for voltage to ground. If voltage is low, work towards the battery. If voltage is OK, work towards the pump. If the relay doesn't pull in, troubleshoot back through the LH towards the EZF. Does the tach bounce as you crank on the starter? Bouncing suggests that the CPS is OK, no movement points to not. You get the idea. Diagnosing is the logical process of systematically eliminating things it might be. Each step narrows the remaining options by half if you do it right.
03-28-2017, 09:26 PM
#34
Rennlist Member
Thread Starter
So...
Fuel pressure is confirmed OK with a pressure gauge?
Then on to ignition, where we suspect that X is causing no spark. Actually a list of X's.
----
What was worked on last? That's often a good place to start if it's all all even remotely related to symptoms. The RL jury can help you decide what's related.
After that, it comes down to some basic electrical troubleshooting, either to make the fuel pressure come up, or get a spark. In either case, start at one end and work towards the other end of the system. Go from the "underperforming" end if you wish. I like to start in the middle of each system under question, halving the list of probable causes with each test. For the fuel system with no pressure for instance, I check to see if there's full voltage at the fuse with the key on and cranking. There's a tiny hole in the back of the fuses that will take a needle probe. Use that to test the circuits without disturbing anything. Test both sides of each fuse for voltage to ground. If voltage is low, work towards the battery. If voltage is OK, work towards the pump. If the relay doesn't pull in, troubleshoot back through the LH towards the EZF. Does the tach bounce as you crank on the starter? Bouncing suggests that the CPS is OK, no movement points to not. You get the idea. Diagnosing is the logical process of systematically eliminating things it might be. Each step narrows the remaining options by half if you do it right.
Fuel pressure is confirmed OK with a pressure gauge?
Then on to ignition, where we suspect that X is causing no spark. Actually a list of X's.
----
What was worked on last? That's often a good place to start if it's all all even remotely related to symptoms. The RL jury can help you decide what's related.
After that, it comes down to some basic electrical troubleshooting, either to make the fuel pressure come up, or get a spark. In either case, start at one end and work towards the other end of the system. Go from the "underperforming" end if you wish. I like to start in the middle of each system under question, halving the list of probable causes with each test. For the fuel system with no pressure for instance, I check to see if there's full voltage at the fuse with the key on and cranking. There's a tiny hole in the back of the fuses that will take a needle probe. Use that to test the circuits without disturbing anything. Test both sides of each fuse for voltage to ground. If voltage is low, work towards the battery. If voltage is OK, work towards the pump. If the relay doesn't pull in, troubleshoot back through the LH towards the EZF. Does the tach bounce as you crank on the starter? Bouncing suggests that the CPS is OK, no movement points to not. You get the idea. Diagnosing is the logical process of systematically eliminating things it might be. Each step narrows the remaining options by half if you do it right.
03-29-2017, 12:20 AM
#35
Team Owner
its also possible that the low battery has damaged the running relays with undervoltage.
If the CPS is old then the connector will probably fall apart.
it would also be wise to replace the TPS short harness this is near the test port Roger sells them.
Note the TPS connector is made of the same material as the CPS connector
If the CPS is old then the connector will probably fall apart.
it would also be wise to replace the TPS short harness this is near the test port Roger sells them.
Note the TPS connector is made of the same material as the CPS connector
03-29-2017, 12:19 PM
#37
Rennlist Member
CPS failures are quite common. I've not gotten 7 years from one yet. Of course, my cars are driven. As I recall, the manufacturing process shifted to China. The old and new ones looked similar but the plastic wasn't well bonded to the metal sensor on one of them I inspected.
03-29-2017, 09:18 PM
#39
Team Owner
only use bosch for electric parts
03-29-2017, 10:52 PM
#41
Do you have an extra ignition switch hanging around that you can test with? If so unhook the connector from the switch in the car, plug spare one in and use a screw driver to crank it over.
03-30-2017, 10:17 AM
#43
Rennlist Member
Hey battery voltage been confirmed from from battery -- > starter -- > alternator -- > t14 connector?
03-30-2017, 08:40 PM
#44
Mine's running, but I'm not that happy because I still don't really know what it was. I pulled the CEP and looked for anything loose behind it. It was out to fix the recirc flap and replace the fan motor. Then I pulled the EZK connector which hadn't been touched and hit it with some DO100 and plugged it back in. Started in four turns and after a short drive idles nice.
Cross posted in case it gives you any ideas.
Cross posted in case it gives you any ideas.