Timing off on one bank?

[Maxium]

I've noticed that I have the slightest miss at idle. I decided to data log and come to find out it's misfiring on one bank (Driver side bank). This almost only happens during idle and sometimes on deceleration and only misfires 1-2 times per cylinder per 5 miles or so. Almost all tune up items are new including injectors.

A while back, I swapped to PI cams/intake and during that time I changed the head gaskets. I'm starting to suspect the timing being off by just a little on that bank despite me triple checking the orientation of all the components. A couple questions come to mind before I decide whether or not to re-time the whole thing or not. First off, is this a timing issue? If so, is it because of me being "off a tooth" or is it a matter of degreeing the cam? I would think that being off a tooth would create a more dramatic misfire effect than 1-2 misfires over a course of 5 miles, or would it?

I really don't want to re-time the whole thing. help a guy logically deduce what's going on. Thanks.

 

[nyuk98gt]

Maxium,

If your timing was off by a tooth, you would feel it in the form of poor idle (not just a slight miss), poor mileage, low power, and, perhaps, a rich or lean code popping up.

New plugs? If yes, what gap? New wires? Did you test fit the plug boots on an old plug to confirm a good fit of the metal clip? The boots slide on the wires and one or two may need a little adjusting. Did you use a little dab of dielectric grease on the inside of each boot? Moisture in the wells will cause the problem you describe. How's the battery? How's the alternator? How's the fuel filter?

Please list your mods so we know what is under the hood.
***edit: Nevermind! It's all there in your "Garage" link. ***end of edit
Chris

 

[trombonedemon]

I'm seeing that your have the larger throttlebody and upper plenum. That alone is gonna give a little more shake and gurgle in the engine and car's exhaust while decelarating.

If you are really worried about it then go back and cross your t's and dot your i's. Like checking for vacuum leaks and fouled plugs, what Nuke suggested w/the dielectric grease.

 

[nyuk98gt]

Maxium,

Compression check will show up a mistimed cam, too. Forgot to mention that in my previous post.

Chris

 

[Maxium]

Hey guys, thanks for the replies and suggestions. Let's see, to start, my idle seems pretty good with a bit (only just a bit) of a shake. I can tell that it misses at idle when i feel the "fish bite on the line" feeling. My gas mileage is not great (around 14-15 mpg city), but no codes to speak of. Plugs are brand new, gapped at .54 i believe, wires are brand new as well. The wires came pre-greased with dielectric grease. The alternator is brand new (motorcraft) as well and the fuel filter is about a year old. I thought I found the source of the problem when i discovered a crack in a vacuum line, but after I replaced the entire set of vacuum hoses, the problem remained. Oh, and the compression check came back with all cylinders being around 180 psi, +/- 5 psi. (As you can see, I've run the gamut of trouble shooting).

Over the weekend I decided to set the timing chains again just to eliminate the possibility of it being a timing issue. It seems to be doing better. I've only gotten one misfire at idle on cylinder 8 (the same problem side however). If the bad mileage and slight misfire continues, I may start looking into exhaust issues. What do you guys think? Thanks again.

 

[ooraceredgt]

Maxium,

Compression check will show up a mistimed cam, too. Forgot to mention that in my previous post.

Chris

Sorry to hijack this thread but I need help too.

My car is having issues with the passenger bank as well. I have been told that the cam is out of time resulting in un burned fuel showing up in the exhaust. I have had a compression test and a leak down test performed and they came back good. Is there anyway to check the cam timing without pulling the valve covers? also, could a bad ecu cause my problem? Just at my ends with this car

 

[nyuk98gt]

ooraceredgt:

If the [aftermarket] cams are mistimed, there is a good chance that there will be PTV resulting in a bent valve that will not hold pressure in a cylinder. Since Maxium's compression test on all cylinders is good, we can almost rule out mistimed cams.

I don't think that there is a way to check cam timing without removing the front cover and cam covers. If you are getting a rich code on one side but not the other and the injectors and coils (or coil-on-plug) are working properly on that side then it is more likely that the cam timing is off on that side.

Were the f-52 cams degreed when they were installed? The keyway in the stock cam gear is not tight so the gears can be 'off', timing wise, by several degrees plus/minus. Nick McKinney (modularheadshop.com) offers "zero degree cam gears" so that the cams don't 'need' to be degreed, just installed using the Ford shop manual method.

HTH,

Chris

 

[ooraceredgt]

To my knowledge the cams weren't degreed. Guess I'll bite the bullet and pull the valve cover and front cover to check the timing. Man I didnt want to do this. Oh well

 

[nyuk98gt]

ooraceredgt:

You have an Diablosport so you can datalog, right? Take a look at the data before you make an appointment with the shop. Maybe you have a sluggish O2 sensor, maybe a cat is plugging up, maybe you have an exhaust leak on the other side that is skewing the corrections and causing the rich condition, etc., etc. The datalogging takes some time and you may need several datalogging sessions but your time is "free" as opposed to the shop time.

Let us know what's going on, please. Lots of help is available on this site.

Chris

 

[ooraceredgt]

i went out to try to datalog my car with the predator this morning after reading what was posted yesterday. yesterday i tried starting my car and it would barely run. i ended up killing the battery so it reset everything. this morning i started my car and it ran perfect for about 2 minutes then it fell flat on its face and started missing and running like ****. i dont know if the reset of the system after the battery died had anything to do with it. if i get the car running again, where do i start and what do i need to look for when datalogging with the predator?

 

[nyuk98gt]

ooraceredgt:

Cold start means open loop operation. After a minute or two, the engine will switch to closed loop and run off the O2 sensors.

Where did the current tune come from? Is this a new problem or has it existed since the cams were installed? Your LT’s will need longer O2 sensor delays to counter the cooler exhaust gas. The delay is adjusted (adapts) but the range may not be broad enough. Anyway, that is another story.

Datalog items (add more as you wish):
MAF counts
load
RPM
STFT’s (both sides)
LTFT’s (both sides)
O2 sensor voltages (both sides)
spark
VS (vehicle speed)
manifold pressure (boost pressure)
AFR

If you have a pressure leak on one side then it would run rich and the other lean. And, as mentioned about the exhaust leak, it can cause the same unbalanced problem. And I hate to say it but a cam could be mistimed like the shop said.

The datalog can be sent to your tuner so he can tweak the tune. Idle and low throttle driving takes some time to get just right. What has me concerned is that the engine runs well when cold but not so good when warm. This sounds more like a tune issue rather than a physical (cam timing, manifold leak, exhaust leak, ???) issue.

HTH,

Chris

 

[ooraceredgt]

I meant to also say that I also notice that the drivers side header was hotter than the passenger header. Don't know if that has any relevance or not. I appreciate all the help and tomorrow I will try to data log as what I can. Thanks