Wanted to bounce this off you folks for some hopefully inspiring input...

Recently I have been experiencing a no-start condition when the car has been driven then parked for maybe 20 or 30 minutes.

A press of the start button lights the car, which then goes on an erratic (sounds like it is missing on a few cylinders) idle, and dies. Repeated starts product the same results.
Feathering the throttle and holding RPMs up to about 2000 (it still hunts and tries to die) will clear the rough idle after about 20 seconds. At that time the car idles and operates normally. At no time does the CEL come on, nor does a basic scanner show fault codes.
An educated guess says the fault probably lies somewhere in the open loop configuration, as the car seems to function normally once in closed loop. Yet a cold start fires every time... Frustrating....

Can anyone list other possibilities, or what I should be looking for?

Kinda has me worried as I would think a failed sending unit would generate a CEL... That may leave the ECU (Yikes!) as the only thing I can think of... Or maybe heat soak of some kind?

Thoughts or ideas?

Thanks,
Vince

 

Any of quite a few things such as dribbly injectors (probably not), faulty temperature sensor (causes wrong fuelling), faulty MAF (ditto), maybe an air leak. More possibilities exist I'm sure.

It's tough for it to figure a code when things are wrong but plausible, especially during open loop.

 

There was a TSB (JTB00268) to do with difficulty starting after a short period:

Situation: The customer may report a rough engine start or stall following hot soak of 20 to 30 minutes.

Cause: Fuelling calibration not robust for the market winter blend 10% ethanol fuel.

The solution was to get the firmware updated in the Powertrain Control Module.

It is possible you have picked up a tank of fuel with high than normal ethanol content?

 

Thanks for that....

My last few fill-ups have all been from top-tier companies, but in truth I have never been a fan of 76 fuel (I prefer Chevron). The 76 is just conveniently a block from my home and gets used more often than I like for just that reason....

I'll go hit a non-ethanol station on my next fill-up and see how that works out...

Thanks again for the TSB, as I hope it is as simple as that!

Vince

 

@ u102768

Can't find a copy of that JTB online (my collection only goes up to JTB00175v3)

Can you tell me the listed Time for the task and any other numbers particular to this fix? (Flash version? VINs affected?)

Called the dealership and he said the flash would take about 1.5 hours or more(Excuse me?). I suspect it is a 20 minute task so I hope to be in and out with a one hour labor fee.

Thanks!

 

Vince,
I get my alcohol free gas at Auburn Cenex next to PEP Boys; South of downtown Auburn just pass 18 as Auburn Way bends left.
IC engines need fuel, air & spark I suspect fuel.............

But why no code? unless it's one of those Jaguar secret codes that don't show on non OEM readers.

Good Luck, Adrian

 

0.3 hours - see attached.

 

Being IT, I suspected as much....

Thanks u102768, you rock!

@ Britania, Thanks for the tip.... I have 5 stations here on the Peninsula, but only 2 carry premium. Easy enough as both are less than 13 miles from me!

 

Not that it is going to help but I thought I would share that I have the same issue. I just haven't had a chance to look into it and address. I thought of it more as an annoyance. As per other posts, I will keep an eye on the gas I am using and see if there is a relationship to weather as well and post back.

 

Reviving an old thread, as this just happened to me a couple of times today. Warm temperatures today and took the car out for a drive, came home, and then attempted to leave again a short time later, result was rough idle and then died. Restart and die. Restart and keep the revs up, then it settled into normal idle. (Actually had this happen two separate times today.)
Pretty sure the gas in there was from last November, so the above TSB is likely the solution. Need to do more driving to use up this winter gas! (Then get off my **** and finally fire up and play with SDD.)

 

How many miles the car got and when the last time you change the spark plugs and gave it a tune up?

 

Ummm… Did you read the thread? It’s a heat soak issue, fixable via a software update to properly handle winter gas in summer temps (and it basically runs the fan longer after shutdown until the temp sensor reaches a lower value). If I read the TSB correctly, it only applies to NA models, not the Rs. In my case, got about 45K miles, no recent tuneup or plugs.
This will be the first year I’ll be dailying this car for the summer, and it still has a tank of winter gas in it.
Revived the thread in case some new owners are waking up their cars and run into the same issue.

 

On my old Mustang I had both 4-barrel carbs blow out their power valves which drained fuel into the intake while it sat after running. I could restart it within a few minutes, but if I waited more than maybe five minutes it wouldn't start easily until maybe ten minutes after that. It was either a bit of hydrolock caused by reduced quench volume due to excess liquid (fuel) in the chamber or by soaking the plugs. Maybe a bit of both. After the 20 minutes or so either the fuel soaked down past the rings and/or the plugs dried off and it'd start fine with the typical Whump-Whump-Whump cuz 13:1 compression.
ANYWAY, and my point.... maybe the injectors dripped/drained and filled the cylinders and/or fouled the plugs for a bit? Same symptom, different causes cuz of course Fuel Injection.
Just a long distance stabbing with a bullet with zero illumination for a problem that could be somewhat related.

 

bumping this old thread as i have experienced this once or twice this summer, only in a heat soak condition. i've never had a true no-start, but it certainly comes real close: from go, i can count a full second at least between the first and second firing of any cylinders. cold starts are full throated and idle high for 10-15 seconds as expected. battery is about 1 year old now, has never been strained by accessory drain with the engine not running, and tested healthy right off the shelf believe it or not (actually you'd have to, i posted about that back then).

i always start button first with a brake tap, i don't ever goose the throttle during start, i haven't used CRC 1-tank for over a year and don't use any other additives, i do not have residual "winter fuel" in the tank (unless of course the gas station has it in the ground, unlikely now that it's nearly september), i buy fuel from the exact same location (mehhh... okay... kroger) virtually every time (with occasionally an excursion, but only to a specific chevron location, which i haven't done this year).

just clocked 89K miles, haven't done any work on fuel or ignition systems since i've owned it (about 4 years and about 22K miles), and i have just read the top 5 other threads on the subject and don't see these two questions answered already. other opinions also welcome of course.

anyone know whether the TSB for the 4.2L describes something also applicable to the 5.0L?

should i use an additive in the car's tank right now, either as a test or as a remedy?

 

The TSB is clear. As with most software patches, they are usually rolled up into a new release (if applicable) to the new platform.
It seems you are doing all things right. I find most additives are just snake oil. But at 90k miles on a direct fuel injected engine, you could be all gunked up in there…. and that wouldn’t help. Niether would a gunked up throttle body or maf, mas, pcv valve …
Boils down to servicing.??

If I may suggest, Have a read of the workshop manual, especially the parts on customer complaints and pin point tests. It is interesting, enlightening, informative.

Cheers.

 

Thoughts. 1. fuel filter blocking. 2. Fuel pressure is not over 55 pounds in the fuel injector areas.
The fuel line maybe developing vapor lock. Always start with the cheapest fixes when you are not that sure of the cause.

 

for sure! but since it was issued sept 2013, after my car was manufactured, i wondered whether it's possible early-ish 5.0L's might still have been affected. couldn't find anyone saying for sure theirs was, nor a TSB that says 5.0L on it (my google-fu might just be poor).

appreciate the additional info!