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Won't stay running except. . .


I'manedgeowner

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There's a lot about "engine won't stay running" here but I couldn't find anything with these conditions.

 

Background, I have a 2008 Edge with the 3.5L engine that just turned over to 40,000 miles. Everything has been well maintained. I have a Ford VCM with IDS and I can't find anything related to the problem using it. I had the car towed and the tow truck driver disconnected the battery because he thought the problem was with resetting the fuel inertia switch. It isn't.

 

Yesterday I was driving in town and the problem first showed up as the throttle not getting any response. My first thought was fuel filter or fuel pump. The car stalled and I rolled over to the side of the road. The car restarted but run sluggishly. I drove about another mile and the car stalled again. It restarted again but ran even worse for about another 100 yards and stalled again for good. I had the car towed home. Today I removed the "air inlet assembly" as Ford calls it--the air box between the filter box and the throttle body. The car started and runs fairly well while cold. I didn't try taking it out of the driveway. Put the assembly back on and the car won't run. It starts and runs for a fraction of a second and then stalls. I can smell fuel so it doesn't seem to be a fuel delivery problem. This is where I left it for today.

 

Without any codes or obvious problems I don't want to spin my wheels looking for the problem unless that's my only option. I'm hoping someone has had a similar experience and can offer some help or knows the car and engine well enough to have insights I don't. I work on cars and know a fair amount but not this one. The car was part of an inheritance and not typically something I work on. If I bought a 3.5 it would have been an Eco Boost. That's me. Not the car or engine.

 

Thanks for reading.

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Not a lot of miles for a 2008. Was it driven mostly city/short trips? 40k would be quite a bit of wear/tear in that case.

 

When were the oil and filter last changed. Does this problem occur across fuel fillups? Have you tried running a fuel injection cleaner through the tank? Does the condition of the oil look good? How about trans fluid?

 

Check the spark plugs/pcv valve, clean the MAF sensor and the throttle body.

 

A new battery might also be called for, but at a minimum, I would do a KAM/PCM reset to let the PCM learn YOUR driving style.

Edited by WWWPerfA_ZN0W
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If it runs without the air intake on I would think it may have a clog in the intake system, air filter. when you had it running without the intake on did you have the mass air sensor disconnected?

When cars sit for a long time they seem to become hotels for rodents. I had a Chevy pickup that used to sit for a year and then made a run to New Jersey from Connecticut every year. Just about every time it was used it had mice living in the air filter.

This car has low mileage and probably sat for long periods on time between uses. If you had the mass air sensor disconnected and it ran it is probably a faulty sensor.

;)

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Thank you for the responses.

 

The fluids look fine. I change the oil every 6 months although no where near the usual oil change miles have been put on the car. I haven't changed the trans fluid but it looks good. I will do it once this is figured out. I got the car with 30,000 miles 5 years ago and my parents were religious with maintaining the scheduled work per the booklet that came with the car and I've kept that up but doing the work myself.

 

40,000 is low but the car does get used regularly but usually just for local trips. As I said the tow truck driver disconnected the battery thinking the inertia switch needed resetting but unfortunately if there were any codes they got wiped out. The only MAF data available comes from after the battery was disconnected. I normally run a minimal data logger but it was taken out to put in an insurance company logger to lower my rates. Once that was returned about a month ago I never put the logger back in. Kicking myself over that. As for the fill ups, no. This was an immediate problem with no warning. The only ongoing issue I've had with the car has to do with the ABS.

 

The throttle body seems like it might be an obvious problem considering what I've found searching the innerweb. Seems to be a consistent problem with the no start, won't run issues but I never saw anything about the engine will run with the air inlet box removed. Might just be me but taking it out and seeing if the engine will run without it is an obvious place to start and if it is a partial solution it would be mentioned. Funny you mention rodents. I did find what appears to be obvious signs but located above the radiator by the hood latch. The only time the car sat for any period of time was for 6 months 2 years ago so I doubt rodents caused this.

 

Injectors? Can't rule them out but I dealt with injector problems before and never with a problem that hit them all at once without a poor performance build up to the total failure.

 

The convertor wouldn't be an obvious problem without a "check engine" light build up to the failure. Never did and still don't have the light on.

 

Yes the sensor was disconnected along with the vacuum line that goes to the inlet box. If one of these two is the problem I would guess the vacuum line before the sensor. Do you agree? I will look up the sensor test procedure although I don't have a manual for this car and I hope the procedure is a standard to go along with what I do have. I have multiple truck shop manual editions and manuals for performance modular engines.

 

Something else I've found out and I don't know if this is "normal" or not. Normally the car is to be started without the use of the throttle pedal. I tried starting with the throttle at WOT but when I released the key from position 3 (start) to return to position 1 (run) the starter remained operating until I put the key in the off position. I can see where this might be a useful test mode but it's an operation I've never heard of.

 

Unfortunately the fuel filter for this car is located in the tank and permanent but seeing that it will run I've ruled it out. No codes about the fuel pressure either.

 

Thanks again everyone.

Edited by I'manedgeowner
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Update, I did not have air flow sensor disconnected like I said I did. The air intake box which is between the air filter box and the throttle body has 2 lines connected to it. A vacuum line as I said and the other is a hose to the PCV valve. I realized this when thinking I had disconnected the sensor and thought I would reconnect the air intake box without connecting the sensor to see if it still ran. Obviously I realized my mistake.

 

I'm thinking of first replacing the air flow sensor. If that doesn't solve the problem I'll try a salvage yard throttle body. If that works then I'll look at getting a new one. If the problem still isn't solved then all I can think of considering the information I have is the problem is with the PCM. I just can't imagine other possibilities failing without any warning and since it does run with the air box removed what else is there that would be a total failure only with the box installed?

 

I was also wondering about the AC. There's not much in the Powertrain Controls\Emissions Diagnosis Manuals that doesn't involve the AC and AC is not a system I use much or know much about. Most my engine work involves deleting it.

 

Please share your opinions. I really want to avoid chasing the problem with replacing parts one at a time to locate the problem. It's an expensive and\or inefficient way to fix anything.

 

EDIT: I did recently get a letter about the fuel tank recall. I don't see how the hanging straps could cause this but any chance this is the problem? There are no leaks or unusual fuel odors.

Edited by I'manedgeowner
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Thanks for the verification Paul.

 

WWWPerfA_ZNOW.

 

Thanks again. No, it wasn't clogged. It wasn't even dusty unlike the filter box. Can you explain to me what the purpose of this box is? I'm use to the tube from the filter going directly to the throttle body. With you mentioning "resonator" it suggests more is going on with this box then meets the eye. Does the 3.5 have an injector pulse dampener? Seems I remember reading at one time about an engine that used a "resonator" for intake and injector pulse instead of a dampener. Might be apples and oranges here though.

 

I've ordered a new MAF sensor and unfortunately it's Friday. It's going to sit for the weekend.

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WWWPerfA_ZN0W,

 

That opens a can of worms if your up to it starting with, if removed where would the PCV hose go to? My experience the PCV has been similar to that of the O2 sensor. There are optimal locations and bad locations. Other then that I can see how what you describe can effect intake and injector pulses. Using the pulse for scavenging is all about following the wave harmonics. I'm still curious about the dampener. I'll look in to it over the weekend.

 

Enigma-2,

 

The fuel pump, fuel pressure or fuel filter were my first thoughts when this happened. It was a typical "not getting gas," condition. Trying to finesse the throttle the few times it did stay running just stalled the engine. Once it ran with the intake box removed though I didn't think fuel would be the problem. I'm not suggesting I know for sure isn't the the problem but I don't see how the conditions would relate to fuel. It seems to be air. If the fuel system was a return type with a dedicated pressure regulator I'd still be on fuel. If I'm missing something let me know. I really know very little bout this car and how it works. Modular motors I know pretty well but not this one.

 

No codes. As I said the tow truck driver thought the problem might be inertia switch resetting and he disconnected the battery so all I can say is no idiot lights were on. Once I got it started any codes I would get would be from a cold start so they wouldn't be much use if a code did get thrown. From what I've read searching the internet, what seems to be similar problems also didn't throw any codes even without the memory being cleared. I can't check any of the test procedures because typical to Ford, wiring, color and pin selection isn't standardized. I have a power probe but I don't know enough to have any confidence chasing voltages during various conditions of the sensors with the manuals I do have, Mustangs, F series trucks and GT's.

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Interesting read but my problem hasn't been intermittent. It showed up and never went away. It only runs with the intake box removed which removes the MAF from the air intake although it is still connected. I never did pull the connector to see what would happen? I'd also like an explanation of the throttle body binding when hot. What's binding, how and why? I don't know how accurate this is but I have heard unlike a choke in a carburetor the throttle plate in a throttle body shouldn't be manually operated. If so it could be sensitive to binding.

 

I have Ford's IDS so anytime the car was connected to Ford any updates should have been installed. I also doubt any updates in years had anything to do with engine operation and have been limited to "Sync" or the infotainment system. I don't use "Sync" so I don't get real time updates like anyone using it does.

 

I can't get past a fuel problem so I'm thinking before replacing the throttle body if the MAF isn't the solution I'll pull the tank (PITA) and replace the fuel filter. I don't think much of the "permanent" filter anyway. I'm not sure what this permanent filter is but I think I'd like to just remove it and install one external to the tank.

 

When this happened I had driven less than a mile so the engine couldn't have been that hot unless I'm way off base about the source of the problem. It was the hottest day yet though when this happened. Weather channel said the high for the day was going to be 94 but the bank in town had 102.

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WWWPerfA_ZN0W,

 

I sent an email to a buddy and this is what I heard back. The fuel pulse dampener wasn't standard on the 3.5 Edge in 2008 in North America. It did end up on some. Usually at the center of the front rail but some had it on the rear rail.

 

The resonator is about the pressure wave and is used to control harmonics. It's actually called a Helmholtz resonator and primarily controls volumetric efficiency of air flow through the engine. I was told don't remove it, specially if your an aggressive drive and at a higher altitude. It can cut the life of the engine by more than half.

 

EDIT, I wouldn't have driven it. I don't even drive it with the intake box removed. Removing it just let me know it will start and run without it. I was just curious if disconnecting it would have any effect on if the car started or not? Being a cold start condition I doubt it but. . . .

Edited by I'manedgeowner
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I can't get past a fuel problem so I'm thinking before replacing the throttle body if the MAF isn't the solution I'll pull the tank (PITA) and replace the fuel filter. I don't think much of the "permanent" filter anyway. I'm not sure what this permanent filter is but I think I'd like to just remove it and install one external to the tank.

 

When this happened I had driven less than a mile so the engine couldn't have been that hot unless I'm way off base about the source of the problem. It was the hottest day yet though when this happened. Weather channel said the high for the day was going to be 94 but the bank in town had 102.

This rang a bell with me. I had something similar happen to me back in the 80's. I gased up at a remote station and the car started to choke about 1/2 hour later. The garage found the gas had been full of gunk (later, after the a**h*** was out of business and left town, we all learned that he had pumped another station's in ground tank dry, gunk at the bottom and all, and took it here to the station I had used. (As had dozens of other people). Anyway it had clogged the tanks pickup, fuel filter, carb filter and car jets. (Stuff was fine, got through the filters but "clingly" was the way they described it to me). Getting it all clesnef out cost over $300 (again back in the 80's).

 

Any chance you got a bad load of gas?

 

Any chance the car sat for a time and the gas had Ethanol which may have separated out, drew moisture to it and turned gunky?

 

Had a snow blower I had let sit over summer with Ethanol gas and it clogged the small jets in the carb. Poured in a 1/4 can of Sea Foam, ran the engine for a while to get the Sea Foam into the carb, shut it off and let it sit for a week. The Sea Foam disolved the gunk and cleared the jets.

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Enigma-2,

 

It could be bad gas. I've got a summer place up north and going there is the only time the car actually gets used by what most would consider typical use. I haven't gone to even open up yet this year. I try to keep the tank full but it's not uncommon for me to take 2 months to get to 3/4 of a tank from full. I couldn't even guess at what the blend is in the tank now.

 

What still stumps me with what your thinking is why does it start and run with the intake box removed if it's bad gas, clogged filter or some harmful effect on the pump from bad gas? It seems to me that these problems would ultimately be mechanical and removing the intake box would have no effect on the no start, no run condition.

 

Wouldn't removing the intake box create a lean condition from removing the control on the airflow? The PCM should add the extra gas needed to return the air to fuel ratio to the PCM range of 14.1 to 15.5. Because all of this is still working doesn't it suggest nothing is inhibiting fuel flow? On Ford's the sensor hierarchy is the MAF takes priority over the O2 sensor so even though you might get a check engine light, the PCM is going to run the engine by the MAF and TPS in this situation. If your thinking something else I'd like to hear it. Beyond tracking down the bad component or mechanical issue I'd like to understand what has happen with this engine.

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What still stumps me with what your thinking is why does it start and run with the intake box removed if it's bad gas, clogged filter or some harmful effect on the pump from bad gas? It seems to me that these problems would ultimately be mechanical and removing the intake box would have no effect on the no start, no run condition.

Stupid question time. Did you change the air filter?
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