Very rough idle at cold start
#1
Very rough idle at cold start
I have a new to me 2015 F Type R with 26K miles with a brand new fully charged battery. After the car has sat for a day or so, when I start it idles extremely rough on "fast idle" around 1350 rpm. Sometimes the tach hunts around for a minute around 1350 rpm then the idle drops to 650 rpm but it is still very rough with car shaking etc. It sounds like its not running on all cylinders. If I put the car in gear, the motor almost stalls out. After 2 to 3 minutes, the idle smooths out and the car runs great after that. Usually it does not throw any codes but sometimes it throws P2275 bank 1 o2 sensor 3 stuck rich and PO300, P0301, P0305, P0302 mis fires. The strange thing is that It seems that the more days the car sits, the worse this cold start idle is.
I am thinking maybe its the MAF sensor is bad until it warms up a couple minutes then it runs fine? Where is the MAF sensor on 5L Coyote? Too many sensor for me to tell....anyone have a picture with an arrow?
I am thinking maybe its the MAF sensor is bad until it warms up a couple minutes then it runs fine? Where is the MAF sensor on 5L Coyote? Too many sensor for me to tell....anyone have a picture with an arrow?
#2
Let's start at the basics: this is not a Coyote 5 litre engine - that is a Ford engine. Your engine is a Jaguar-designed engine made under contract at the Ford Bridgend plant for use in Jaguars and Range Rovers, not Fords.
but the symptoms and codes suggest a problem with injectors - not uncommon in GDI engines of any make. You might try (should try) a can of BG44 cleaner as a first step.
but the symptoms and codes suggest a problem with injectors - not uncommon in GDI engines of any make. You might try (should try) a can of BG44 cleaner as a first step.
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#3
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#4
Oh boy all sorts of potential causes. Could be a significant vaccum leak that seals itself up when the top of the motor warms up. Not likely to be a bad MAF IMHO. It's running rough in OPEN LOOP mode which means its ignoring the 02 sensors. At idle it's probably ignoring the MAF too and strictly monitoring rpms and IAT. It COULD be a sticking injector, flooding one cylinder, robbing the others. Put a stethoscope on 'em and listen to 'em clicking. Check fuel pressure with OBD2 (I am told there's a PID) or with a gauge on the fuel rail schraeder (anyone, does F-type motor have this?)
EDIT: I don't know if the GDI injectors are visible from the outside to PUT a metal stethoscope tip to. Someone more familiar with this motor than I can probably comment.
Ok, ok, diagnostic plan.... I'd put a $15 vacuum gauge on there and see what it tells you. Read a "How to read a vacuum gauge" page on the web. I suspect either a vacuum LEAK or valve damage / problems on one or more cylinders. You can find vacuum leaks by spraying around the intake manifold gasket with brake cleaner -- WARNING ITS FLAMMABLE! WEAR EYE & FACE PROTECTION IN CASE IT GOES WHOOSH! HAVE FIRE STANKWASHER NEARBY. Or you could just pay a shop to "smoke" the manifold --- pressurize it to 1-2psi with a smoke machine --- be sure and tell them to do it COLD and avoid joining the Michael Jackson hair-fire for men club.
Per other comments I"m leaning towards a sticking injector; does/did car sit, undriven long periods of time??? Bottle of Techron and an "italian tune-up" may be indicated. Certainly can't hurt. I'm credentialed to perform such work if nobody else is available.
The MAF sensor is the thingey between the air filter and the intake manifold, single multi-pin connector, plastic tube with a thermistor in the airstream at one end of the "snorkel" or the other. I don't think that's your problem.
HTH
EDIT: I don't know if the GDI injectors are visible from the outside to PUT a metal stethoscope tip to. Someone more familiar with this motor than I can probably comment.
Ok, ok, diagnostic plan.... I'd put a $15 vacuum gauge on there and see what it tells you. Read a "How to read a vacuum gauge" page on the web. I suspect either a vacuum LEAK or valve damage / problems on one or more cylinders. You can find vacuum leaks by spraying around the intake manifold gasket with brake cleaner -- WARNING ITS FLAMMABLE! WEAR EYE & FACE PROTECTION IN CASE IT GOES WHOOSH! HAVE FIRE STANKWASHER NEARBY. Or you could just pay a shop to "smoke" the manifold --- pressurize it to 1-2psi with a smoke machine --- be sure and tell them to do it COLD and avoid joining the Michael Jackson hair-fire for men club.
Per other comments I"m leaning towards a sticking injector; does/did car sit, undriven long periods of time??? Bottle of Techron and an "italian tune-up" may be indicated. Certainly can't hurt. I'm credentialed to perform such work if nobody else is available.
The MAF sensor is the thingey between the air filter and the intake manifold, single multi-pin connector, plastic tube with a thermistor in the airstream at one end of the "snorkel" or the other. I don't think that's your problem.
HTH
Last edited by wadenelson; 07-01-2020 at 05:40 PM.
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All AJ133 and AJ126 engines are direct injection and there is no schraeder valve in the system due to the pressure it operates at.
One tell tale sign of sticking injectors is excessive smoke from the exhaust. Bear in mind that if an injector sticks open, raw fuel can find its way into the sump and also damage the catalyst by melting the core.
One tell tale sign of sticking injectors is excessive smoke from the exhaust. Bear in mind that if an injector sticks open, raw fuel can find its way into the sump and also damage the catalyst by melting the core.
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Carbuff2 (07-02-2020)
#7
Thanks for the rapid reply. So there IS a PID for fuel pressure monitorable with an OBD2 scan tool? I mean, who wants a gasoline shower if all ya gotta do is plug in?
I've melted cats on turbo Subarus that were running rich. Not a cheap date. And oil in the crankcase is VERY quick and easy to see, measure, smell...
I've melted cats on turbo Subarus that were running rich. Not a cheap date. And oil in the crankcase is VERY quick and easy to see, measure, smell...
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wadenelson (07-01-2020)
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Hours of fascinating reading!
The AJ133 was designed back in 2008 and first plonked in a Jag in 2009.
Note this pdf covers both the NA and SC versions but the NA version has never been put in an F-Type and it was replaced by the AJ126 (SC only) in 2013.
The AJ126 is essentially a cut down version of the AJ133, with the rearmost cylinders "missing" and both a smaller bore and stroke.
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wadenelson (07-01-2020)
#10
#11
#13
It's ALMOST impossible to be too rich under WOT or hard acceleration. (too rich, wealthy, too beautiful, **** too large, too rich under acceleration... things that are just not possible! /s)
While the ECM may be throwing the code when you lean on the pedal it actually TESTS the 02 sensor for "stuckness" either at idle or under cruise conditions.
It does this by deliberately enriching/enleaning the mixture and watching to see if the upstream 02 sensor on that bank responds.
Several possible causes. Stuck injector as we've been discussing. Fuel pressure ABOVE spec? Manifold air leak causing one or more cylinders to run lean @ idle or when cold, ECM correcting by richening the mixture up on that side, then when it gets on the highway its WAAY too rich. Now this is sort of a lie, the "adaptions" are usualy RPM dependent, but
By any chance is your air filter clogged? Shop rag left in the intake, MAF? Lack of air can cause a rich just as easily as too much fuel!
... just thinking out loud here... I'm not a drivability technician, I just play one on the Internet....
While the ECM may be throwing the code when you lean on the pedal it actually TESTS the 02 sensor for "stuckness" either at idle or under cruise conditions.
It does this by deliberately enriching/enleaning the mixture and watching to see if the upstream 02 sensor on that bank responds.
Several possible causes. Stuck injector as we've been discussing. Fuel pressure ABOVE spec? Manifold air leak causing one or more cylinders to run lean @ idle or when cold, ECM correcting by richening the mixture up on that side, then when it gets on the highway its WAAY too rich. Now this is sort of a lie, the "adaptions" are usualy RPM dependent, but
By any chance is your air filter clogged? Shop rag left in the intake, MAF? Lack of air can cause a rich just as easily as too much fuel!
... just thinking out loud here... I'm not a drivability technician, I just play one on the Internet....
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Paul_59 (07-03-2020)
#14
One time the car would not even stay running on s cold start. It would start and die after couple seconds. I kept starting it and after about 5 starts it barley kept running extremely rough shaking all over like it was only running on 4 cylinders. Over a minute it improved and was idling okay but a little rough still. So I took it out on the road and it was back firing like crazy(not the normal f type pops) but backfiring. So I limped home and the next day when I started it ran perfectly normal!!!
I am not the original owner so I do not know when/if the air filter elements have ever been changed. What is the procedure to change them....from the wheel well or?
I am not the original owner so I do not know when/if the air filter elements have ever been changed. What is the procedure to change them....from the wheel well or?
#16
I think OzXFR did. He used the brake booster vacuum line to pump the stuff in. I'm sure he will chime in. Check his posts there is a thread about it with photos.
Last edited by RGPV6S; 07-02-2020 at 03:59 PM.
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Paul_59 (07-03-2020)
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In a few days time I will be putting a second can through, right before an oil change.
Of course without dismantling the top end I can't be sure it did anything much, but judging by the amount of black soot inside the exhaust tips after the "shakedown run" I reckon it cleaned up a fair amount of carbon crud. And I have had zero running/engine problems since, if anything it's performing better than ever.
#18
One time the car would not even stay running on s cold start. It would start and die after couple seconds. I kept starting it and after about 5 starts it barley kept running extremely rough shaking all over like it was only running on 4 cylinders. Over a minute it improved and was idling okay but a little rough still. So I took it out on the road and it was back firing like crazy(not the normal f type pops) but backfiring. So I limped home
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Serious backfiring is often an intake valve not closing; again, this would be rapidly disclosed using a $20 vacuum gauge and 20 minutes of study on the Inner tubes on how to use it. All my diagnosis experience is NOT on Jaguar so I 'd have NO IDEA how or where to change the air filter on one. Sorry!
Two of 'em, a minor PITA to access and replace (compared to 99% of other cars), but very unlikely they are the root cause of the OP's problem as they rarely if ever clog up or get dirty enough to cause major problems.
#20
See here for the latest post about the F-Type air filters: https://www.jaguarforums.com/forum/f...4/#post2254016
Two of 'em, a minor PITA to access and replace (compared to 99% of other cars), but very unlikely they are the root cause of the OP's problem as they rarely if ever clog up or get dirty enough to cause major problems.
Two of 'em, a minor PITA to access and replace (compared to 99% of other cars), but very unlikely they are the root cause of the OP's problem as they rarely if ever clog up or get dirty enough to cause major problems.
Hey Ox
I understand that you have another thread with pictures when you used the CRC product? Where did you insert it in the engine?