Honda 600f4i No Spark

[Alan_RHIT]

Could the ECU be shutting off the voltage to the coils? If the ECU was shutting it off would the injectors be firing cause I finally pulled an injector and found out it wasn't firing....Also I seem to think the ECU is fine because it has an anti theft wire that doesn't unlock it until it receives 9V and then primes the pump....well the pump primes...so it must be somewhere else....

[Auerbach]

When I worked on the 05 GSXR in my roadster, I found that if the anti-theft was not bypassed, the fuel pump ran for about 1-2 seconds after power on but when bypassed correctly the fuel pump ran about 5 seconds until pressure built and it shut itself off.

Also I had the stock gauge cluster which allowed diagnostics via codes. It was a great help when I couldn't find "up" on the bank angle sensor.

A friend of mine has a F4i with the stock electronics in his FSAE car and we used a resistor rather than a 9 volt battery for the anti-theft. I'm not sure what ohm it was but I'm sure it's on this site somewhere. Just a thought...

[Alan_RHIT]

So I ran a series of tests...The battery is good 12V...I get 12V at both terminals of the coil...I crank the engine and the battery drops to 10.5 and the terminals at the coils drop to like 1.8V...I checked the cam pulse and ignition pulse generator both checked out as fine...the pump still primes and i ran the codes and it said the issue was the ignition pulse generator which doesn't make a whole lot of sense...I checked the termials at the injectors One is 12V and the other is 0V and when I crank one drops to 1.8V and the other increases to 1.3V...I have no idea anymore...I also changed the 9V battery to a 2.2 Kohm resistor which also makes the pump prime...Any suggestions?

[B Lewis @ PE Engine Management]

I am not sure what the root cause is, but if the coils and/or injectors are not receiving battery voltage when trying to start it will never fire off.

[Alan_RHIT]

Is there anyway to test my ECU? It spits out error codes and causes the pump to prime..could it still be bad?

[Alan_RHIT]

For those of you still tuning in by accident last night I brought a couple of the grounds across the steel braided fuel line and heard the injectors click....but still no spark or injectors even when i ground it to the fuel line...I thought maybe a bad ground so I grounded it to my car...still nothing...i'm ready to set the engine on fire and call it a day....

[Tom W]

Originally posted by Alan_RHIT:
Is there anyway to test my ECU? It spits out error codes and causes the pump to prime..could it still be bad?

Very very hard to have an ECU that is actually faulty. I've always dealt with MoTeC systems so haven't had to deal with bypassing anti-theft systems but if voltage to the coils is dropping during cranking then that sounds to me like a pretty good system to stop an engine getting started if a sensor is saying that it is being stolen. If I was you I would be quadruple checking the anti theft bypasses.

And good luck, these things are always stupidly frustrating! But on the bright side you aren't actually at a competition looking stupid because your car won't start like we were in 2007.

[Alan_RHIT]

Okay guys I know it has been awhile but I ordered an ignition switch with key cause i'm so freaking fed up with this...SO I KNOW the ANTI THEFT is by passed....still no spark the voltage just dies on the power line to the injectors and spark plugs...I think if I could hold 12V on this line it would fire right up....but I don't know what is going on...

[moose]

I know there was talk of the battery earlier - but have you tried swapping that out? Do you have a nice big charged up car battery around to use? You mentioned that it drops from around 12 to 10.5 while cranking. I don't remember how low is OK, but thats certainly near the border - and its too easy not to try to test.

[Alan_RHIT]

Yeah i've swapped through like 3 or 4 batteries...the drop on the battery is fine I think the real issue is the wire coming from the ecu....that has 12V and then dies while cranking...