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Won't stay running except. . .


I'manedgeowner

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enigma-2,

 

Didn't change the air filter. It was changed in the fall and still looks new. It probably has less than 500 miles on it. I did remove it, put the cover back on and it still didn't start.

 

WWWPerfA_ZN0W,

 

Thanks for that. Much more organized than the Powertrain\Emissions manuals. Unfortunately I have no codes though. I'm curious if you posted this because of a disagreement with what I wrote? As far as I know it's standard for all MAF controls. When fuel used doesn't match expected demand the system defaults to MAF controls unlike MAP systems.

Edited by I'manedgeowner
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WWWPerfA_ZN0W,

 

Glad to hear this. I have visited internet sites where corrections in what someone wrote or just differing opinions are viewed as a lack of civility or outright verbal assaults. Unfortunately when reviewing these sites they generally lack depth and substance and participants generally walk softly. I can only say for myself if someone thinks I'm wrong about something I want to know it. Whether the criticism is right or wrong I learn by it. Either I research the argument and learn where I am wrong or I bolster my comments with information to support my comments which I originally failed to supply. I'm better off either way and I'm never offended by disagreements. I have gone a bit off topic with this but only for a better understanding. And again, thank you for the link. I like how it cuts out much of the "process" involved with using the manuals.

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WWWPerfA_ZN0W,

 

I was corrected last night about what I said about a PCM defaulting to MAF tables. What I wrote was true with the closed loop, narrow band O2 sensors. Apparently it's not true with the engines that have open loop, wide band O2 sensors that use the PCM to limit engine power output. I don't have any experience with PCM's that limit power output. It's a useless strategy for what work I do on engines. Interceptors are needed with stock OEM, PCM's when stage 2 and 3 performance modifiers are added to an engine to allow the enhanced performance to be realized.

 

This is what I was told from what has always been a reliable source. Do you have anything to add?

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Any PCM/ECM that uses knock sensor data to change timing advance is going to automatically limit power output given that the conditions dictate it. More critical on forced induction engines than naturally aspirated ones.

 

If a MAF sensor is being used, and it is disconnected, the PCM will use default values and the engine will run like c*** when driven. As with any other component in the engine, the PCM assumes that the MAF is a fixed size with a fixed response rate etc. That is why when you change the MAF sensor, it is usually best to go with OEM because the set values for stimuli (i.e. voltage for flow rate) are the same. Now if you instead installed a MAF that uses different set values for the same exact stimuli, then the PCM would not be able to respond or adjust correctly, the engine would run like c***, and codes would get set.

 

Same goes with VCT solenoids. If they are not functioning correctly or are disconnected, the PCM has no choice but to use default set values, which may be something like 10 degrees of advance, which of course is not right for most conditions the engine will see.

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WWWPerfA_ZN0W,

 

That's some good information you've shared. The person I talked to designs the fuel delivery systems for Honda racing bikes. He does everything from designing the IC chips to programming to fitting everything to the bikes. I get the impression you and he could sit down and have a conversation that would be Greek to most of us. While educating me he spent a fair amount of time also explaining the workings of the knock sensor along with real and false data strategies, the effects forced induction engines with turbos have and how the TPS fits in with a MAF engine. Your mentioning the same was affirmation for me of some comprehension on my part. It's not unusual for me to wonder about what just happened after a PCM strategy discussion that involves extended cause and effect relationships. I appreciate the time you and others have taken here with my engine problem.

 

I cancelled my order for the MAF sensor this morning. It was still on back order and I found another source while ordering some injector pigtails for a Coyote. Thought I'd share the information here in case anyone else is looking for one. I'm not sure of the forum policy for mentioning dealers so I'll just they're on Ebay. They're new Ford OEM take off's from a company that uses the engine for generators and industrial machinery. He buy's them from that company and is selling them for $18 with free USPS shipping. He also has starters, alternators and other stuff with the same kind of pricing.

 

Thanks again.

Edited by I'manedgeowner
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I feel humbled to say the least. I am not well-versed in automotive mechanicals, tho I do try to puzzle things out, figuring there's got to be logic in it LOL.

 

Hope you have luck with the eBay MAF. I tried one such takeoff (from a reputable company) made not a whit of difference. I caved and bought a Hitachi off of RockAuto, as it said it was OEM product. So far, so good!

 

HITACHI MAF0012 {Click Info Button for Alternate/OEM Part Numbers} Sensor Only Info Heart.png
Actual OE Part
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WWWPerfA_ZN0W,

 

All I can say from what I've seen is you're informed and offer advice freely when you can. You're not alone either. I have seen forums where there is an expectation of knowing everything already to participate.

 

The MAF I ordered should be a Hitachi than. It came off a new but never used Ford engine.

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The MAF sensor I ordered came yesterday but didn't see it until this morning. There's a bench test read out for it showing it's within specs. It's exactly the same as the one off the car including the part number which apparently isn't made anymore. This part begins with 3L3A while the current Hitachi part number for the car is 3L3Z. Everything else is the same. This isn't unusual for Ford though. Now it needs to be a solution.

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Thanks. As posted in another topic I was given information on this. Also, my Ford access expired at the end of June and I need to get that taken care of.

 

Edit: I also need to get the manuals for this engine. At least the Powertrain\Emissions diagnosis manual for 2008.

Edited by I'manedgeowner
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