User Tools

Site Tools


newenginewontstart

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
newenginewontstart [2009/02/04 12:44]
twdorris
newenginewontstart [2012/01/31 11:26]
dmertz
Line 4: Line 4:
 ====== Details ====== ====== Details ======
 When a new engine doesn'​t start, you have to check the basics: computer, fuel and spark When a new engine doesn'​t start, you have to check the basics: computer, fuel and spark
 +
  
  
 ===== Computer ===== ===== Computer =====
-First, verify that the ECU is powering up and seems to be functioning normally. ​ Observe the check engine light when you first turn on ignition. ​ It should come on for five seconds and then go back out.  If it stays on constantly, then suspect something related to the ECU and/or wiring leading up to it.+First, verify that the ECU is powering up and seems to be functioning normally. ​ Observe the check engine light when you first turn on ignition. ​ It should come on for five seconds and then go back out.  If it stays on constantly, then suspect something related to the ECU and/or wiring leading up to it.  In addition to the check engine light test, check to see that the in-dash stock boost gauge needle moves up to about the half-way mark and stays there when you turn the ignition key on.
  
 Try to get ECMLink to connect to the ECU before trying to start the engine. ​ This will help greatly in your debugging efforts, if they are needed. ​ If you can get ECMLink to connect, you will have not only confirmed 100% that the ECU is up and running OK, but you can also start some basic checks before the engine even turns over.  Start an ECU stream (ECU->​Stream on) and check that intake temp, coolant temp, TPS, etc., all make sense. ​ For example, if you see stuff like -40F for intake temp, then you may have a [[BlownSensorGround]]. Try to get ECMLink to connect to the ECU before trying to start the engine. ​ This will help greatly in your debugging efforts, if they are needed. ​ If you can get ECMLink to connect, you will have not only confirmed 100% that the ECU is up and running OK, but you can also start some basic checks before the engine even turns over.  Start an ECU stream (ECU->​Stream on) and check that intake temp, coolant temp, TPS, etc., all make sense. ​ For example, if you see stuff like -40F for intake temp, then you may have a [[BlownSensorGround]].
Line 15: Line 16:
  
 There are probably a number of other debugging tips to go here too.  Fill in as you see fit. There are probably a number of other debugging tips to go here too.  Fill in as you see fit.
 +
 +
  
 ===== Fuel ===== ===== Fuel =====
 First, verify that the fuel pump is pressurizing the fuel rail.  Hopefully you have a fuel pressure gauge for this purpose. ​ If not, you can disconnect the fuel return line from the pressure regulator and run it into a gas can or something to confirm that fuel flows out when the pump is activated. First, verify that the fuel pump is pressurizing the fuel rail.  Hopefully you have a fuel pressure gauge for this purpose. ​ If not, you can disconnect the fuel return line from the pressure regulator and run it into a gas can or something to confirm that fuel flows out when the pump is activated.
  
-If you can connect with DSMLink, verify that the ECU is trying to pulse the injectors while cranking (view InjOn). ​ If throttle position (ThrotPos) is too high while cranking, you may be invoking the cranking fuel cut feature in DSMLink ​intended to help users clear out a flooded engine.+If you can connect with ECMLink, verify that the ECU is trying to pulse the injectors while cranking (view InjOn). ​ If throttle position (ThrotPos) is too high while cranking, you may be invoking the cranking fuel cut feature in ECMLink ​intended to help users clear out a flooded engine.
  
-It's also possible to plug the injector resistor pack into the ISC's connector. ​ They are both identical 6-pin connectors and are located close enough to each other in the engine compartment to be confusing. ​ If you do swap these, the injector resistor pack will get very hot with the key on and, of course, the engine will certainly not start. ​ You can see a picture of this wired incorrectly below. ​ Note the black wire with yellow stripe on the connector plugged into the ISC.  If you refer to the 1G MFI schematic, you'll see that there is no black wire with yellow stripe on the ISC connector. ​ But there is one on the injector resistor pack connector.+It's also possible to plug the injector resistor pack into the ISC's connector. ​ They are both identical 6-pin connectors and are located close enough to each other in the engine compartment to be confusing. ​ If you do swap these, the injector resistor pack will get very hot with the key on and, of course, the engine will certainly not start.  Doing so will also possibly damage the ISC drivers in the ECU.  You can see a picture of this wired incorrectly below. ​ Note the black wire with yellow stripe on the connector plugged into the ISC.  If you refer to the 1G MFI schematic, you'll see that there is no black wire with yellow stripe on the ISC connector. ​ But there is one on the injector resistor pack connector.
  
 {{http://​www.dsmlink.com/​images/​forums/​injiscswap.jpg}} {{http://​www.dsmlink.com/​images/​forums/​injiscswap.jpg}}
newenginewontstart.txt ยท Last modified: 2024/03/15 11:16 (external edit)