Ongoing Coyote Problem
 

I'm at my wits end trying to resolve an issue that's been ongoing since last season. To start, I have a gen 1 motor with 3000 miles on it. I'm experiencing fluctuating hesitation upon hard throttle. It's not a linear hesitation. It's more like a sputtering hesitation. I also have sporadic pop coming from the exhaust at idle. Not a backfire but an intermittent spit/pop kind of sound. The exhaust isn't blowing any smoke. I also have knocking at lower RPM's under normal throttle. My gas is fresh with the correct grade. I changed the mass airflow sensor and no luck. I looked for vacuum leaks but I can't find one unless I overlooked something. I pulled the spark plugs and they look normal to me. My dealer was very gracious in giving guidance. I was told to data log my car using SCT Live Link. I have the Lund tune by the way. He was concerned about the following variable valve timing readings.

VVT exhaust bank 1: actual value -.12 min value-3.37 max value 31 Avg 7.0
VVT exhaust bank 2: actual value -.12 min value -1.4 max value 31 Avg 7.0
VVT intake bank 1: actual value 0.0 min value -47 max value 1.25 Avg -5.5
VVT intake bank 2: actual value .07 min value -47 max value 1.3 Avg -5.6

These numbers were logged going no more than 4500 RPM since the problem worried me. I backed off to prevent any possible damage. He claims the banks shouldn't read this far apart from each other. Should only be a percent or two.The knocking is also reading on the log results, but the engine is adjusting timing to compensate. The fuel trim numbers looked good since the engine wasn't calling for more fuel. We pretty much ruled out a clogged filter or pump issue. I don't understand why it's knocking in the first place. It's quite audible. I checked for any parts rattling against the engine to rule out false knocking. The only things I found were the chrome metal coil covers and hood prop rod. The covers did rattle so I put a small bead of RTV sealant under the corners and it stopped it. The prop rod was rattling against the metal oil fill cap. I wrapped some thin foam around it and it fixed it. I plugged an OBD reader into the port and got no fault codes. I'm not sure if my problem has something to do with an electrical issue. I hope this doesn't have to do with a VCT solenoid. I don't know how I'm going to get the valve covers off given the very little room between them and the fender well.

Any guidance is much appreciated. Thanks.

The VCT solenoids are a problem area.
They look to be very easy to change and are cheap$. I don't know if loosening your motor mounts and lifting the engine a bit will help your access issues.

https://www.youtube.com/watch?v=dIwqJ_hdcSo

I appreciate your guidance spdbrake but lifting a motor in a home garage type setting isn't possible. I want to rule out everything before I have to go that unfortunate route. The video was helpful though. Thanks.

I would check for faulty grounds first, if they all pass, then check for faulty sensors. If they all pass then data log what your tune is commanding for VCT and what the engine is responding with for VCT. If they don't match, it's time to go back to the VCT solenoids. If they do match then the engine is poorly tuned and you need to properly tune it.

Now I remember why I have a stinky ole carbureted engine.

I know, I know! Not being helpful!

What sensors should I be focusing on? Wouldn't a faulty sensor throw a fault code which I am not seeing?

If you are using one of Ford's ECUs they use the OBD2 fault codes which provide a fault code for just about anything. When you see your code, if you don't recognize it just google it and you will get the story.

If you use the data logging approach watch for a sensor that is not reporting data or reporting suspicious data.

Actually, the EFI systems are easier to troubleshoot than a carb because carb systems have no equivalent to OBD2 trouble codes and do not come with data logging capabilities. The trouble codes and data logging capabilities let you see what is amiss. Without the equivalent, you just have to start a hunt and peck search routine which is both time-consuming and frustrating.

I decided to tinker around more today. I pulled the PCV valve, vapor hose and the fitting at the intake that the hose clicks into. I noticed quite a bit of oil at the intake fitting. Unless this is normal, I'm concerned. The PCV valve clicks back and forth when I shake it. From past experience that would be normal operation? If something is wrong, please let me know how to proceed. Thanks.


http://www.clubcobra.com/forums/pict...ictureid=20366

http://www.clubcobra.com/forums/pict...ictureid=20367

Forgot to mention something. I didn't realize there was a cavity at the front of the motor that gave access to the underside of the intake manifold. A rodent must have gotten in there to store some reserves for the winter. See photo. I snaked an inspection camera in there and discovered them. They could have been rattling against the knock sensors leading to unneeded timing adjustments by the PCM. I tied a small flexible hose to the camera arm, then to my shop vac, and surgically removed them. I should have gone to med school.

http://www.clubcobra.com/forums/pict...ictureid=20368

Sounds like "a hunt and peck search routine" to me.

Yep.

The nut shells don't have enough mass to affect a knock sensor, and if they did the VCT won't split out on one bank. Would be Pi$$ poor design to have the engine have one bank producing more power and firing out of time.

The PCV oil is pretty normal and can be eliminated by adding a catch can. Usually needed as rings have more blow-by via age or Super/Turbo charging.
Several companies make kits.
Example: https://www.youtube.com/watch?v=qkqdhEIb5QU

Every one, there are only a half dozen or so and you already know you have a problem with cam phasing so you ought to go to the commanded vs reported cam phasing as a starting point.

Be sure to check your OBD II error codes if any are present. They can save a lot of uninformed stumbling around looking for a problem.

The oil is not enough to worry about and a catch can will only make the catch can manufacturer richer and add no value except give you one more thing to look at and fret about.

I don't know if I follow you on the command vs. reporting. I'm assuming reporting pertains to a scanner reading a value but how is a command initiated?

Commanded is what the tune is calling for.

Reported is what the data log shows is actually happening.

Finding a significant difference provides you fertile ground to dig around in.

Most likely they will match. The actual "delivered" is based on the rating of the fuel injectors. It's not a volume measurement but an calculated amount based on the lb/hr rating of the injector and the pulse width of the firing cycle.

So, have you verified that the injectors and the tune match?

Gotcha. My next question would be how do I read what the tune is calling for? I originally plugged in my SCT scanner (which holds the Lund tune) into the OBD port. There was an output port, on the scanner, that plugged into my laptop for logging via the LiveLink program on my laptop. That's how I got the figures I previously posted. What I was asked to log was the following...

accel pedal position relative
engine coolant temp
intake air temp
knock sensor
load
maf frequency
measured afr bank 1
measured afr bank 2
rpm
short term fuel trim bank 1
short term fuel trim bank 2
spark advance
spark advance V2
throttle angle actual
torque source
total misfires
VVT exhaust bank 1 actual
VVT exhaust bank 2 actual
VVT intake bank 1 actual
VVT intake bank 2 actual
vehicle speed mph

I don't have the scanner plugged in right now but I recall it had some sort of diagnostic/logging feature. Don't hold me to that. Will this read what the tune is calling for?

No. Not sure how to do that. I forgot to mention that I also have a Innova scanner I used as well. Maybe I can check from there? It has the option "scan for codes > system status > all module scan". I think I may have stated this before but both scanners show fault codes.

You'll have to expose (even possibly remove) one of the injectors to get the manufacturer's part number. If it's a stock crate engine they should be able to tell you what they have installed. Then check Lund to see what he's programmed into the tune.