S4 Turbo II no injector pulse
#1
S4 Turbo II no injector pulse
So my car has been undergoing a bit of work over the past few months. Nothing terribly major, but I've run into an issue at this point.
I have a Power FC and Banzai Racing adapter harness and when I attempt to start the engine the injectors are not pulsing despite the Power FC showing it's percieved duty cycle.
Here's what I have done so far in an attempt to correct the issue:
I've also cleaned all of my grounds besides the starter ground. I have fuel pressure while cranking and a very strong spark from the coils. I cannot figure out whats going on, absolutely no fuel sprays from the primaries during start up. Prior to the Power FC install, I was having an issue with the engine bucking while under light load which I thought was TPS related (replaced with a new one now).
Never had any issues starting and idling though, just random lean spots while going over bumps and turning. Also if I had the car idling to operating temp, I would open the door and sit down and it would die as if the engine was out of fuel and then start right back up no problem (I figured this was related with the issue of going lean over bumpy roads, hence the reason I replaced the old broken harness thinking there was a short).
Any ideas? I'm stumped.
Thanks,
Steven
I have a Power FC and Banzai Racing adapter harness and when I attempt to start the engine the injectors are not pulsing despite the Power FC showing it's percieved duty cycle.
Here's what I have done so far in an attempt to correct the issue:
- Verified that the Power FC is not faulty
- Replaced the engine harness with a new OEM one
- Replaced the injectors with new DW units
- Checked the "eng inj" fuse and it's not blown
- Checked the resistors in the resistor pack and they are within spec (6.3 ohms)
I've also cleaned all of my grounds besides the starter ground. I have fuel pressure while cranking and a very strong spark from the coils. I cannot figure out whats going on, absolutely no fuel sprays from the primaries during start up. Prior to the Power FC install, I was having an issue with the engine bucking while under light load which I thought was TPS related (replaced with a new one now).
Never had any issues starting and idling though, just random lean spots while going over bumps and turning. Also if I had the car idling to operating temp, I would open the door and sit down and it would die as if the engine was out of fuel and then start right back up no problem (I figured this was related with the issue of going lean over bumpy roads, hence the reason I replaced the old broken harness thinking there was a short).
Any ideas? I'm stumped.
Thanks,
Steven
#6
Check voltage at the injector connectors. The PFC only supplies ground to open the injectors.
Also since you have a PFC the injector wire are 4W, 4X, 4Y, 4Z, but again that is not for checking voltage.
Pull the UIM, use a spare injector connector on the injectors and supply 12V & ground , listen for a click on each and check for spray on the secondaries.
Fuel pump should prime as soon as you turn the key to the on position, it should not just have fuel pressure while cranking. Double check your connection to the COR.
Also since you have a PFC the injector wire are 4W, 4X, 4Y, 4Z, but again that is not for checking voltage.
Pull the UIM, use a spare injector connector on the injectors and supply 12V & ground , listen for a click on each and check for spray on the secondaries.
Fuel pump should prime as soon as you turn the key to the on position, it should not just have fuel pressure while cranking. Double check your connection to the COR.
#7
Check voltage at the injector connectors. The PFC only supplies ground to open the injectors.
Also since you have a PFC the injector wire are 4W, 4X, 4Y, 4Z, but again that is not for checking voltage.
Pull the UIM, use a spare injector connector on the injectors and supply 12V & ground , listen for a click on each and check for spray on the secondaries.
Fuel pump should prime as soon as you turn the key to the on position, it should not just have fuel pressure while cranking. Double check your connection to the COR.
Also since you have a PFC the injector wire are 4W, 4X, 4Y, 4Z, but again that is not for checking voltage.
Pull the UIM, use a spare injector connector on the injectors and supply 12V & ground , listen for a click on each and check for spray on the secondaries.
Fuel pump should prime as soon as you turn the key to the on position, it should not just have fuel pressure while cranking. Double check your connection to the COR.
I will try this method when it cools down a bit outside. As far as the fuel pump is concerned, it primes when the key is switched on and then runs as it should during cranking.
Thanks
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#8
Check voltage at the injector connectors. The PFC only supplies ground to open the injectors.
Also since you have a PFC the injector wire are 4W, 4X, 4Y, 4Z, but again that is not for checking voltage.
Pull the UIM, use a spare injector connector on the injectors and supply 12V & ground , listen for a click on each and check for spray on the secondaries.
Fuel pump should prime as soon as you turn the key to the on position, it should not just have fuel pressure while cranking. Double check your connection to the COR.
Also since you have a PFC the injector wire are 4W, 4X, 4Y, 4Z, but again that is not for checking voltage.
Pull the UIM, use a spare injector connector on the injectors and supply 12V & ground , listen for a click on each and check for spray on the secondaries.
Fuel pump should prime as soon as you turn the key to the on position, it should not just have fuel pressure while cranking. Double check your connection to the COR.
#12
I spun the cas and I could here the injectors working (clicks and mainly hissing sounds from each as I spun it). I installed that cas and tried the same method with the original one, same results. I then tried to crank the car with my extra one, no start.
#15
Thank you
Edit: the clock's issue is in the warning light panel itself, but the horn's intermittent issue could be related to the odd loss of power going over bumps in the road if the CPU points need to be re-soldered correct?
Last edited by Daedalus704; 07-26-12 at 01:21 PM.
#17
Thanks
#18
Moderator
iTrader: (1)
In my past comment I meant to say "w/the car running and the key to on." But if you want to bypass the Main Relay all you would need to do is remove the four wire plug to the relay, which has two plugs in all, and jumper the B/G to B/Y and B/W to W/L. You can then see if the relay was faulty and thus the cause of your problem although don't leave the jumpers in place as this could eventually drain the battery.
#19
Fuel pump will prime since you are getting power to the ECU and COR with the key in the on position, ths issue appears to be when you turn the key to start. This is when it is critical that the power to the ECU does not get interupted. Power is supplied by the main relay to pin 1C.
A quick test is to push start the car. If it starts and runs then you have narrowed down your search. Keep in mind that all the fuel injector testing has dumped a lot of fuel into your engine.
A quick test is to push start the car. If it starts and runs then you have narrowed down your search. Keep in mind that all the fuel injector testing has dumped a lot of fuel into your engine.
#20
Fuel pump will prime since you are getting power to the ECU and COR with the key in the on position, ths issue appears to be when you turn the key to start. This is when it is critical that the power to the ECU does not get interupted. Power is supplied by the main relay to pin 1C.
A quick test is to push start the car. If it starts and runs then you have narrowed down your search. Keep in mind that all the fuel injector testing has dumped a lot of fuel into your engine.
A quick test is to push start the car. If it starts and runs then you have narrowed down your search. Keep in mind that all the fuel injector testing has dumped a lot of fuel into your engine.
#21
Moderator
iTrader: (1)
Have you checked the voltage at pin 1C (for your aftermarket Power FC) w/key to start? The voltage should be 12 volts w/key to on but upon startup the voltage would drop as voltage is supplied to the starter. Voltage would normally drop down to around 9 volts or so. If it is too low then it might not be enough to power the PFC thus causing your problem.
#22
Have you checked the voltage at pin 1C (for your aftermarket Power FC) w/key to start? The voltage should be 12 volts w/key to on but upon startup the voltage would drop as voltage is supplied to the starter. Voltage would normally drop down to around 9 volts or so. If it is too low then it might not be enough to power the PFC thus causing your problem.
#24
No they have not. Since installing it, the car will not start. I thought it was the fault of the Power FC originally so I had it tested in a FD locally and the car started up no problem. I followed the instructions very closely and verified that my wiring was correct after recieving the adapter harness.