Help Please

NoVaGT said:

I might try just popping the MAFS out and wiping it down. Maybe it got some crud on it.

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Do not wipe it down as you may damage it. Check out the below link for how to clean it.

http://knowhow.napaonline.com/know-how-notes-how-to-clean-your-maf-sensor/

I just checked every hose, the air box lid, everything. It looks fine.

ETA; found CRC MAFS cleaner at my local parts store. I'll clean it tonight.

Remembering how much dried leaves was in the air box, something may have gotten into the MAFS.

So, revised tune after data-logging loaded up, I cleaned the MAFS, I checked every connection under the hood, and still the shuddering persists.

Next step is to buy a new air filter.

If you want to attach a csv log, just rename it and add .txt to the end, then you can upload it to the forum and others can simply rename it back once they download it.

NoVaGT said:

So, revised tune after data-logging loaded up, I cleaned the MAFS, I checked every connection under the hood, and still the shuddering persists.

Next step is to buy a new air filter.

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Have you tried swapping the old filter back in?

Zimm said:

Have you tried swapping the old filter back in?

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Gone, I threw it out. I'll buy another one next week. It's the factory intake, factory filters, this really shouldn't be an issue.

Well, went for quite a drive yesterday to put some miles on the revised tune I got back from Bama, but the shuddering/bucking is still there. Here's the e-mail I sent them today;

Brandon;


Well, I put about 200 miles on the car yesterday, and the problem hasn't gone away. When cruising in top gear, the car just shudders when the RPMs are between 1500RPM and 2100RPM. It's smooth as butter everywhere else.


Can you please tell me what the issue is you found in the datalogs?


First, there were the three times there were miss-fire CELs that had to be cleared and crank-position sensor relearns done, and I would have expected there to be some sort of ignition issue. Now you're telling me it's a fueling issue, but that's not what it feels like.


Are there two separate issues? Maybe three? Is it not your tune, but something else I need to look at? The crank-position sensor? Un-metered air getting in past the MAFS? I really do think this all started when I put a new OEM air filter in. And replacing the filter is a real PITA, as the lid on the air-intake box is packed in tightly. Maybe something on the intake past the MAFS got damaged and is letting air in at certain RPMs?


The only things done to this car since I bought it new are your tune, one oil change, and one intake air-filter replacement. The car has always gotten 93 octane fuel. What is causing these issues? A tuning issue? An ignition problem? A fueling problem? An intake/filter problem?

You've looked at the data-logs, and you know what they show. What are they telling you? Ignition? Timing? Fuel?

FYI, I briefly drove on the stock/OEM software right before you sent me your latest revised tune, and the bucking/shuddering was still there. That leads me to believe it isn't your tune, but something else.

Thanks for your help;



I haven't had the chance to stop and buy a new air-filter, but I'll do that this evening. Hell, I might try some cheapie from a parts store just to rule-out Ford getting a bad batch of OEM filters that don't seal with the air-intake box lid properly.

Very frustrated at this point.

Oddly, Brandon said that there was too little air getting in at low RPMs, so he leaned out the fuel at low RPMs. That sounds weird. Maybe it does point to un-metered air getting in past the MAFS.

Why not just put the stock tune in and take it to your dealership?

If it's easily replicated they should be able to help.

Commbubba19 said:

Why not just put the stock tune in and take it to your dealership?

If it's easily replicated they should be able to help.

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I'll do that if I can't figure it out myself. Taking it to the dealership is a major PITA, as it's my only car, and traffic/time in this area is a beast of epic proportions.

Car's at the dealership.

I switched back to the stock tune, the bucking at low RPMs continued, then it threw a CEL and had a miss-fire code.

So for that, wear on the steering wheel, a loose seat bottom, it's back at the dealership.

Call from service advisor;

Cracked intake manifold. I think it's really just part of the intake tubing from the air-box to the manifold. Un-metered air is getting in past the MAFS.

I'm not understanding how that causes miss-fires though.

Unmetered air can cause all sorts of issues. Misfires probably from too much fuel or timing trying to compensate for the air it's getting.

Lost Cosmonaut said:

Unmetered air can cause all sorts of issues. Misfires probably from too much fuel or timing trying to compensate for the air it's getting.

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"Misfire" codes mean the engine is trying so hard to compensate for the un-metered air, it causes combustion not to happen? Or "misfire" means detonation that the ECU is sensing?