Engine cranks but will not start

[2Valve]

Well it was good while it lasted.

 

Sunday morning, running my 4th pass, the boat just died. I’m back to a no spark condition, but the injectors are spraying into the throttle body when cranking the engine.

 

Ohmmed out the coil again and it appears fine. 1 ohmon the primary, 8.5k ohmson the secondary, 12 volts present at coil with ignition on.

 

I need to check for dc signal from the ICM to the coil with engine cranking, but the ICM is brand new. Damn.

 

The raw data:

2002 PCM 5.7L

Throttle body injection

Pickup coil sensor replaced

IGnition Control Module replaced

New stainless screws and heat sink compound used for ICM to ensure good ground

Coil wire high tension lead measures 800 ohms.

 

Thanks,

2Valve

 

 

[BraceMaker]

Well Then! Spray means you have signal from the ICM to the ecu so I'd double check your coil wire is seated and breakers or relays.

[eleeski]

Stan had his coil wire fail. It was an intermittent problem so really hard to track down. You have had that distributor cap off a few times and wires do break internally. Just a thought.

 

Eric

[2Valve]

@BraceMaker

Relays will be checked. Thanks

 

[2Valve]

@eleeski

 

The coil wire measures out good and is seated. Strange.

[Andre]

Like @BraceMaker said,spray means good ICM and pick up coil.

Could be intermittent ignition coil ,cap or rotor...

[2Valve]

@Andre

I plan on putting all that stuff under a GD microscope tonight. :)

I am replacing the ignition coil just to make sure that isn't adding to the equation.

 

Thanks,

2Valve

[2Valve]

The puzzle remains unsolved. Haven't had the total time I need to resolve this, but did manage to somehow break the rotor, inside the cap. The little metal tab connecting the center post on the distributor to each plug; somehow cracked and came apart. great.....

 

I have a test light and checked signals again. I have a solid 12vdc to the coil (from the ICM, upper black connector, pink wire) with key on. I had my friend crank the engine over while checking the Ignition Control Module digital signal (to the coil). If good, it should be flashing indicating on and off, which of course fires the coil. Mine just displays a solid light. It could be because I need a LED tester that switches fast enough to see the pulses, assuming they're there.

 

I've worked on a lot of machinery in my years, and solved nearly every type of problem, but I must say, this predicament has me close to dialing the Suicide Prevention Line. :(

[vtmecheng]

I'd start by replacing the cap, rotor and wire between the ignition coil and cap, if you haven't already. Next I'd go to the ignition coil. Sorry if you've already done these, I know you have done a lot already.

[gt2003]

I'd strongly suggest that you allow the wife to buy you a newer boat since the night ride was her idea... Let me know how that goes...

[2Valve]

A 196 Nautique is looking pretty good right about now.

 

I'll give an update when I get it figured out. Hopefully, it can help someone else with this very, very strange problem.

 

btw, can someone shed some light on where the connection is for engine ground? I mean the negative cable from the battery?

 

thanks,

2Valve

 

 

[BraceMaker]

Usually you can find that connection on the drivers side of the block up near the knock sensor. Some of those pulses can be difficult to see on a standard test light so I wouldn't preferentially use that.

 

My guess here is that you have an issue with the switching signal at the coil.

 

 

[2Valve]

@BraceMaker

 

Thank You.

[BraceMaker]

https://easyautodiagnostics.com/misc-index/led-light-test-tool-1

[2Valve]

@BraceMaker

Thank you sir. In the old days of a few years ago, I could just drive up to my local RadioShack after work, and get the parts. :)

 

Thanks for the link.

2Valve

[2Valve]

I wanted to report back on what I ultimately found. The original issue is the engine would crank but not start. I mistakenly went down the path that I was burning up Ignition Control Module's. I spent hours troubleshooting, ohmming out every wire I could think of, checking male and female pins for corrosion.....

 

But this weekend, I installed a completely new distributor, and the boat was running fine in the driveway. Turned off the key and it wouldn't re-start.

 

I had my girlfriend hold the key while I wiggled some connectors and lo and behold, and a hallelujah Jesus!!, I found it.

 

The coil has two connectors. Gray and Black. I was moving the gray connector and the engine instantly fired and idled perfect. While continuing to move the connector, the motor would mis-fire and eventually stall. Ah-hah!!!!

 

This connector has the Tach terminal wire (#1) and the B+ to coil (#2) connections.

 

I removed the connector and inspected the pins for corrosion. Nothing, perfect. So I just spread them out a bit and put a slight twist in them to illicit better contact and re-connected.

 

Perfect.

 

I'm going to splice in a new harness but I'm 100% sure this was the main issue all along.

 

See attached.

 

Hope this helps someone else with a similar problem. Connections can be good. Wires can be good, but sometimes, the fit of the male to female pins themselves can be suspect.

 

2Valve

 

 

 

 

 

[Moffattra]

nice job!

 

when will you be listing it for sale??

[2Valve]

@Moffattra

ahh, no can do. Investing time in machinery warrants an equal investment in enjoyment of said machinery. :)

[BraceMaker]

MAGIC PIXIES!

 

May loose connections inside duplex+plugs are the worst. I'm having that issue with my e46 bmw new wiring harness years back and now I'm getting problems with a crank position sensor fault - somewhere I suspect something like that and that somewhere I suspect to be inside the ECU box.

[2Valve]

Update: The new gray connector didn't completely solve the problem.

 

I installed a new coil and now it's resolved. The female connectors on the coil were the culprit. Since they're embedded deep in the case of the coil, its very hard to service.

 

Spent the weekend pulling passes in the course. Even some older women who slalom skiied for years but now want to run the course.

 

Everything running well, even the Perfect Pass cruise (rpm based). Nice to have a good, strong running motor again.

 

2Valve

[UWSkier]

Good find! That was a tough one.

 

BTW, first post mentioned wife and resolution post mentioned girlfriend... I'm sortof more interested in this story! :)