Here's a pic of me pulling the engine out of my 612 yesterday!

Hey guys... drumroll please...

Well. I have good news and bad news.

The good news is that the car started right up! Sounds just like it did before only the misfire (from a bad cylinder 6) is gone. But some issues persist.

As backdrop, please remember this car was the victim of a hydrolocked motor. This means the intake scoops picked up water and the engine digested it. Smack! Water doesn't compress real well. So, I've taken care of all of the engine repairs (some twice ;-) and there is still a notable issue...

I may not have posted before that when I started the car before (after the 1st rebuild), the headers on the passenger side seems to blow much less air out of them and were much colder. So I went digging back a couple months ago and found that I had a bad cylinder- which I have now fixed.

Well, like anyone else, you'd likely assume that's it! One issue. Fix that and the car is fixed. But alas, that doesn't seem to be the case. I've had about a hundred issues on this car and I've resolved most of them (interior and exterior). But it appears my issue related to the cold air coming out of the passenger side exhaust headers is not solved by my repairing the one bad cylinder (the bent valves).

It appears I have an engine management issue. I now need to determine what the issue is. Essentially the car is running on the driver's bank only. Or just mildly on the passenger bank. So far I've checked fuel pressure, injector pulse, pulled to rail out to confirm pulse, swapped left and right ECUs and the problem still exists...

Well recall that the car ingested water. That water would have made its way past the air-mass sensor, through the (electronically controlled) throttle body and into the motor. I've resolved the motor part. And know the ECUs are fine. So, my current hypothesis is that I have a bad MAF (mass airflow sensor), bad throttle body, or a wiring issue. I doubt it is the wiring issue but I need to check the schematics to see if there is a fuse or relay external to the ECU that interacts with the MAF or throttle body. My leading guess is that all the water ruined the passenger MAF or throttle body.

The remarkable thing is that you can literally feel the difference at the headers in terms of air flow and heat. Also, the passenger headers don't heat up at all while you can literally see the driver's header's catalyst begin glowing red!

So, like I said, looks like engine management. I will need to apply my experience (from 20 years ago) as a engine management engineer at Ford to try to solve this issue. I will start with a review of the schematics. I will then exchange the MAF and then throttle body from one side to the other. Then start pinning out wires to ensure there isn't a break going to the ECU.

Never a dull day bringing a 612 back from the dead!

Until next weekend...

- Jason

 

I haven't swapped them yet... BUT upon a deeper read of the schematics, it appears there is what is called a "motor driven throttle emergency switch". It is under the passenger footwell (for the RHS) and is right where some water got it. I bet that is my problem. Either the throttle body saw water, pulled too much current and popped that switch, or the switch saw water and popped or burned up. Either way, that controls whether or not the throttle plate is able to open beyond an idle condition! Tomorrow I will make a quick check of it!

On the catalyst getting red comment, let me clarify. That is looking into an open header, directly at the honeycomb material. That SHOULD get red. You don't want the overall, integrated header and catalytic converter assembly getting red from the outside, but the internal catalyst material should get red hot!

Stay tuned!

 

Well, more disappointments.

All the wiring to the MAFs and electronic throttles are fine. Including the emergency switches. I even swapped the MAFs and throttles from bank to bank, but same outcome. Driver's bank perfect, passenger bank not firing.

I have fuel pressure, injector pulse, spark.

I then went a found a major ground loose (very) at the bell-housing (my $10/hour assistance and friend never tightened it). So that could wreak havoc.

Also found a broken connector on the passenger crank sensor. I don't think it was failing but it is a possibility. A resistance check suggests it is fine but that only accounts for two terminals of the three.

So, if the bad ground was causing some ground loop failure and the crank sensor isn't the issue, I will then go back and re-check spark and fuel, and look at the power wiring to the passenger side electronic throttle. One last step will be to put a boroscope in the intake and check the throttle plate by camera to see if it is actually opening when I depress the throttle. If not, more wiring and control checks are in order.

Thankfully I have the detailed electrical schematics...

Not losing hope... just incredibly complicated and trying resolution. Hope for the ground being the culprit! I wouldn't be surprised.

 

No codes. That would be too easy! ;-)

 

Probably not! What is that procedure exactly?

Thanks!

 

Thanks! But now I will never know if it was the start-up sequence, the loose ground or the crank sensor!

 

That would be WONDERFUL!

 

I hope you are right! I will try it, along with the new crank sensors and fastened ground strap next weekend...

Thanks!

- Jason

 

I have checked the basics though. Timing, fuel, spark, compression. It is all right. I think the crank sensor is cracked at the connector but fine. By not going through the start up procedure, the car may be confused by not having calibrated one ecu to the other. Interestingly enough, the rhs throttle plate and wires route to the lhs and vice versa. And that is by design and also reflected in the schematics that these Ecus need to know what the other is doing and the start procedure may be the time that this info is communicated. Or the loose ground may have been factor.

 

That's no fnn but it could come to that eventually. That being said, that's 500 miles away for me.

I think there may be a local guy though with an SD3.