Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: welshpaula on January 12, 2008, 06:17:29 PM

Title: eingine "missing" no power any ideas ??
Post by: welshpaula on January 12, 2008, 06:17:29 PM
hiya  its me the newbie to pick your wise brains again !
 i have a jeep cherokee 3.7 ltd auto , eingine keeps "missing" now and again and eingine management light comes on whilst it is on i am losing power when i pull off or accelerate ??
also seems to coincide with me re fuelling ,might just be coincidence mind ?? only had it a week any ideas ??
 paula x
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Post by: droidy on January 12, 2008, 08:45:32 PM
are you using supermarket fuel.
try using good quality fuel like shell or bp.
the problem with the miss fire could be the lambda probe. that will normally play up when poor quality fuel is used.
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Post by: welshpaula on January 12, 2008, 09:07:01 PM
yes using asda or tesco for fuel and unleaded as advised not to use super unleaded ?
can that really cause the problem i have got they must be so sensitive ?
the other thing i thought of is the jeep had been stood on a forecourt  for a while with no fuel and had to be jump started to start as battery flat ,would that cause a problem ?? clutching at straws now lol !
 as its under warranty is it worth having it put on the computer to find the fault ?
 paula x
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Post by: Mike Pavelin on January 13, 2008, 08:00:32 AM
Super wont cause a problem, it's just not necesary.
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Post by: Dave69 on January 13, 2008, 10:47:29 AM
Quote from: "droidy"
are you using supermarket fuel.
try using good quality fuel like shell or bp.



I dont want to sound bad but this statement is utter cr@p. go to your local fuel depot and see what lorries leave, esso, tesco, bp sainsburys. they all use the same filling point.
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Post by: karaltajake on January 13, 2008, 11:35:03 AM
air trapped in the pipes? i had a similar prob with my old citreon, turned out air was getting in from a damaged fuel line!

perhaps oil on the spark plugs?
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Post by: greggmo on January 13, 2008, 01:13:22 PM
Quote from: "Dave69"
Quote from: "droidy"
are you using supermarket fuel.
try using good quality fuel like shell or bp.



I dont want to sound bad but this statement is utter cr@p. go to your local fuel depot and see what lorries leave, esso, tesco, bp sainsburys. they all use the same filling point.[/quote

i must say dave that it does seem that my truck runs crap on tesco fuel compared to shell or bp. bp and shell are different fuel companies so how would they use the same fuel from the same depot? maybe the fuel depot holds fuel for them but not all in the same tanks? this is an interesting question arising here. sorry Paula for the hi jack :oops:
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Post by: Dave69 on January 13, 2008, 02:53:52 PM
the fuel depot by the M42 supplies a good 80% of tankers for the area. Alot of trailers are marked and unmarked and do visit the majority of garages in the area. One thing to remember is at what point the garage orders it replenishment, if too late then the sediment is stirred and most of this is caught in the line filters but some does get through
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Post by: greggmo on January 13, 2008, 06:37:17 PM
interesting stuff. i do think the fuel quality in general is crap though.
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Post by: Dave69 on January 13, 2008, 07:33:51 PM
certainly a post hijack sorry this hasnt' answered the problem
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Post by: welshpaula on January 13, 2008, 08:55:45 PM
lol  dont worry lads  the odd "hijack "never hurt anyone !!
 paula x
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Post by: Bubba on January 15, 2008, 08:57:25 PM
dave is dead on the money they do all use the same bunker/pionts
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Post by: tim_aka_tim on January 16, 2008, 08:41:29 AM
I know where you're coming from with saying it all comes from the same place, but that doesn't explain why supermarket diesel froths up like a pig, yet Shell or Texaco doesn't. Depending upon vehicle, I've also found that Shell diesel always gives more mpg.

In the case of petrol though, I agree, I've seen no noticable difference - though I use little petrol.
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Post by: JamesH on January 16, 2008, 09:07:38 AM
Maybe diesel is different? My van will do 30-40 miles per tank on BP diesel than Shell, Esso or Texaco and 40-50 more than on Tesco fuel  :?:
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Post by: tim_aka_tim on January 16, 2008, 09:45:13 AM
Exactly my findings. Definately vehicle specific. I've always found BP to be crap diesel though as regards mpg.
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Post by: Bigmadgregor on January 16, 2008, 10:04:47 AM
Supermarket chains but their fuel from distressed cargos (ships that have no buyers for their cargo and so can't put in to port) thats why they can offer discounted proces cos they screw the supplier... This can lead to variable supply quality etc.

Yes the fuel does come from the same refinery/holding depot but additives are added differently depending on who the fuel is going to...

i.e. make a big pot of vanilla then add the detergents\additives etc as needed buy buyer. that accounts for why some fuel froths more than others.
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Post by: Panic mechanic! on January 16, 2008, 12:01:08 PM
the frothing on diesel comes down to the make of the pump the fuel is del ivered thru, I drive a truck and bubba will back me up on this but  if you have a hi speed pump ( as required to put diesel in trucks ) it does  froth a lot more all the newer pumps are hi speed and the older pumps are slower!, as to varying degree's of mpg that comes down to how heavy your foot is, tyres, crap carried on board, driving styles etc etc
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Post by: thorna on January 16, 2008, 12:03:38 PM
Hi Welshpaula,
      My sister in law had exactly the same problem on her 2.4 Cherokee, noticed it when pulling up a steep road towing. They thought it was the clutch slipping & took it back to the dealer; turned out to be just one of the HT leads breaking down.
Not sure if that would effect warning lights though.
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Post by: thorna on January 16, 2008, 12:06:02 PM
Supermarket Fuel:
My old school MG engine hates the stuff (Tesco), whilst I hate queing for £60 worth of fuel whilst someone is buying a 20p tin of beans & blocking the lane.
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Post by: Mike Pavelin on January 16, 2008, 12:36:53 PM
The 3.7 has no HT leads or distributor.
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Post by: welshpaula on January 16, 2008, 04:11:38 PM
hi guys back to problem been in today and had ecu read threw up following codes p1899 and po841 anyone any ideas what sort of  faults these show and should i be worried  before it goes in to dealership on tuesday ??
 also both wing mirrors electrics not working at all now ??
cheers  paula x
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Post by: Mike Pavelin on January 16, 2008, 05:46:25 PM
These are automatic transmission related fault codes.

P0841 Low/reverse pressure switch sense circuit
P1899 is not in the diagnostic manual for KJ but usually indicates a Park/neutral switch fault.

If the transmission controller logs a fault it will partially shut down giving the illusion of a loss of power, this could be your problem.

The power mirrors are always going wrong. The power folding mechanisms were sometimes shagged from new.
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Post by: MK1 on January 16, 2008, 06:58:26 PM
Quote from: "Mike Pavelin"
If the transmission controller logs a fault it will partially shut down giving the illusion of a loss of power, this could be your problem.


Is this part of the 'limp home' system?
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Post by: welshpaula on January 16, 2008, 07:34:18 PM
thanks mike ... now to be sexist lol as a woman should i be worried as just bought vehicle from garage and still under warranty ,its not major is it ??
 paula x :oops:
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Post by: Mike Pavelin on January 16, 2008, 10:16:05 PM
Difficult to say but modern automatics can be difficult to dignose unless you know what you're doing. I could be wrong, but the codes are indicating a transmission problem.
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Post by: welshpaula on January 17, 2008, 07:08:52 AM
is that serious .... what i mean is we have just bought it   am i likely to get more problems in the future ??
 paula x
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Post by: Dave69 on January 17, 2008, 07:25:24 AM
got offered a job building auto gearboxes, paying £30k plus and expenses and world travel, turned it down as they are way too complicated now with all the electronics and sensors alongside the mechanical parts
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Post by: welshpaula on January 19, 2008, 04:22:42 PM
hi all
 jeep going in on tuesday management light still on driving in safe mode so i am told ??
 its an automatic  now when i change into park or reverse the whole car jolts ??
 would this be a symptom from the codes i gave above (transmission problems ) sorry but getting worried now !!
 paula x
 all help appreciated !!
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Post by: Mike Pavelin on January 19, 2008, 04:36:43 PM
Yes. Hopefully it will be a simple sensor fault. Is it going to a Jeep dealer?
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Post by: welshpaula on January 19, 2008, 04:39:10 PM
yes much to the dismay of the warranty company who wanted me to find a garage that charged under £50 an hour ,i live in newport gwent ,couldnt find anyone local who could work on it so warranty company and garage where we got it have agreed to jeep in stratstone cardiff doing repairs £100 an hour lol !
 paula x
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Post by: welshpaula on January 25, 2008, 09:52:23 PM
just had my jeep back today,from jeep in cardiff very helpful there i have had a courtesy car all week which they didnt have to provide ,unlike the NOT helpful s**T garage we bought it from ! it was at first thought it needed new gear box !!!!!!!!!!!!
but needed new solenoid (spelling ?) ?? now running lovely just gave her a blast up the motorway!
 we didnt pay as under warranty (garage not happy to pay jeep prices lol !)
 can anyone shed any light on solenoids ? something to do with gearbox ??
  paula x
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Post by: Mike Pavelin on January 25, 2008, 10:03:03 PM
It'll probably have been a pressure solenoid in the gearbox.
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Post by: isle of man on January 25, 2008, 10:04:37 PM
it's a valve basically and it's normally operated electrically and part of the internals of the gearbox....something of a precedo science.






peter henry
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Post by: welshpaula on January 25, 2008, 10:04:55 PM
hi mike
  would that be a bad sign so to speak in a jeep ,only having done 37,ooo miles and 5 years old ,sorry dont have much faith in it now  and worried we are going to be forever paying out on it
 paula x