Honda 600f4i No Spark

[Alan_RHIT]

I know there are about 10 other posts on this but none of them answer this question. I have 2002 Honda 600 f4i that I want to start initially to make sure it runs before I tear into the internals. I just put a completely new fuel system on that works. I have none of the ignition parts. Almost everything is a hot wired job with stock everything ecu etc etc etc.

-Clutch
-Side Stand
-Tip over sensor

I already know about the Anti theft and I took care of it using a 9V battery. When I connect the 9V to the anti theft and I put the start wires in the on position the pump primes itself but when I touch the wires together to crank there is no spark. I have double and triple checked all my connections and the motor is pretty much brand new so I don't think anything would have gone faulty. But any suggestions would be great.

Thanks

[Drew Price]

Are the injectors firing?

If you're not getting ignition or injectors you may want to check at the crank sensor signal and wiring.

If you get injectors but not spark it may be a problem with the ignition system itself, see if you can verify that the coils actually work, and that you have the (-) terminals wired correctly, and that you're getting switched (+) to the coils at ignition keyed 'on.'

Best,
Drew

[Alan_RHIT]

Two questions...first how should I check to see if the injectors are firing? Pull them? Second what do you mean by (-) terminals on the coils? All the coils have connectors that should keep the (-) where its supposed to be and the (+) where its supposed to be right? Also when I measured the voltage in the wires yesterday with it in the on position I was getting like 12ish V in each both wires going to the coil in cylinder 1...

[Mikey Antonakakis]

Originally posted by Alan_RHIT:
Two questions...first how should I check to see if the injectors are firing? Pull them?

You should be able to hear them if you listen carefully.

[Drew Price]

The injectors momentarily see +5v across the two terminals when they fire. A decent volt meter will pick up at least a flutter of voltage change during cranking (it'll probably register as +1.x volt), or an O-scope, or put a stethoscope or even screwdriver against them and put your ear against them - they make a *click* sound when they fire. You could also pull them and leave them plugged in, make sure fuel pump is disabled though - DO NOT SET YOURSELVES ON FIRE.

As for the coils, if you're getting +12 at both terminals with ignition keyed on that's fine, depending on the type of coil (I'm not familiar with the F4i) the power to one lead will be momentarily interrupted, and through magic, this causes the coil to fire.

If you messed with the ECU or the ignition amplifier or rectifier by changing parts it's possible these wires got switched or they are not connected to the right place at all, double-check that too.

If you put in a standalone system see if there's a way that you can test fire the coils, and start at the ECU with a meter and work your way towards the coils making sure that the signal is coming through correctly.

Best,
Drew

[Alan_RHIT]

So i measured the voltage across the two terminals on the coil the wire that runs to the battery is measuring 12ish V when in the on position the wire going to the ecu is seeing 0V and when I crank the 12V goes to like close to 0V...is that right? I didn't pull the injectors but with the coils out it reeks of fuel so i'm going to guess they are firing...any other suggestions?

[Alan_RHIT]

I tested the ignition pulse generator last night with a multimeter and I only got like .03 or .02 volts when its supposed to be much larger at .7 volts...I don't have a honda peak voltage adapter for my multi meter but I believe I should still be able to see the .7 volts without the adapter...Is this my issue and where can I buy an ignition pulse generator?

[B Lewis @ PE Engine Management]

Hi Alan,

I would be very surprised if the pulse generator (crank sensor) is the issue. These are generally pretty robust and as long as there is not a break in the wire they are almost never the issue. The signal coming from the sensor is a sin wave so without a scope or the ability to record a maximum voltage with you multimeter you may not see the peaks.

Also, both the injectors and ignition coils should measure 12v when the ECU is "on" or the engine is cranking. One side of both of these will drop to 0v when they charge (or open in the case of injectors).

Good luck.

[Alan_RHIT]

I just realized i measured the voltage in DC instead of AC..I've done a bit more research and I see that the Cam pulse generator is more likely to fail...when I get home i'm going to check this....When I measure the wires at the connector I get about 12 VDC at each wire that is the live wire and the other wires going to the coils...when I crank the voltages in both wires drop to just above 1 VDC...any other additional suggestions would be awesome...thanks for the input...

[Jon @ Electromotive, Inc.]

I'm not really sure how you're referencing the 12v lead to the coils, but if your measuring from the 12v lead to ground (like the engine block) and the voltage is dropping to 1v, that's your problem. That voltage should stay pretty much at battery voltage. You either have a significant resistance in the line somewhere or it's being shut off during cranking.

[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...