Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: bunnykins on May 16, 2009, 09:36:55 AM

Title: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 16, 2009, 09:36:55 AM
my jeeps been running rough and there is a strong smell of petrol.

i have just changed 5 of the 6 spark plugs [ all 5 of the old ones were black - could not get to the one nearest the radiator ! ]

/ new distributor cap and rotor / and 5 new leads. afterall that its still running rough.

any jeep mehanics out there with ideas what needs attention ?

is it the cat lamda sensor or injectors ? how do you clean the lambda sensors ?

the RAC cleaned the distributor before i changed all the above and it seemed to go fine for 20 mins.

i also filled up £50 of petrol in wales coming home, could it be dirty petrol ?

i also did realised that i ran out of water in my coolant tank before this happened but did top it up.

thanks
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Panic mechanic! on May 16, 2009, 11:20:10 AM
you can't really clean lambda sensors, you just replace them,its good if you can get oem ones but some jeepers including myself have used the universal ones,give lighthouse a call about them ( you can find their number in the suppliers section)
If your jeep is running rich then usually it is down to them, they control all the fueling  to the injectors so change them and then run some injector cleaner as well  and hopefully it should be sorted.
(p.s they can be a complete arse to get out, especially if they haven't had copper grease on the threads when fitted)
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: greggmo on May 16, 2009, 12:14:42 PM
has your catalist gone?
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Bishops Finger on May 16, 2009, 08:48:05 PM
Is it intermittant...?
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 16, 2009, 08:52:20 PM
Quote from: "bunnykins"
my jeeps been running rough and there is a strong smell of petrol.

i have just changed 5 of the 6 spark plugs [ all 5 of the old ones were black - could not get to the one nearest the radiator ! ]

/ new distributor cap and rotor / and 5 new leads. afterall that its still running rough.

any jeep mehanics out there with ideas what needs attention ?

is it the cat lamda sensor or injectors ? how do you clean the lambda sensors ?

the RAC cleaned the distributor before i changed all the above and it seemed to go fine for 20 mins.

i also filled up £50 of petrol in wales coming home, could it be dirty petrol ?

i also did realised that i ran out of water in my coolant tank before this happened but did top it up.

thanks
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 16, 2009, 08:53:11 PM
Quote from: "Panic mechanic!"
you can't really clean lambda sensors, you just replace them,its good if you can get oem ones but some jeepers including myself have used the universal ones,give lighthouse a call about them ( you can find their number in the suppliers section)
If your jeep is running rich then usually it is down to them, they control all the fueling  to the injectors so change them and then run some injector cleaner as well  and hopefully it should be sorted.
(p.s they can be a complete arse to get out, especially if they haven't had copper grease on the threads when fitted)

thank you will ring them monday for one
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 16, 2009, 08:56:00 PM
Quote from: "Bishops Finger"
Is it intermittant...?

yes was intermittant, but now...............its not !

i havent driven it since i changed all the bits as it was still running rough, was not sure what i need to do so better not to drive
as i may damage the engine ?
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 16, 2009, 08:57:05 PM
could it also be the cat ? how much for one of those ?  :shock:
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Bishops Finger on May 16, 2009, 08:59:02 PM
Wouldn't drive it at the mo...hopefully the doc will have an idea

Have you refilled it since the dodgy petrol..?
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Bubba on May 17, 2009, 10:40:56 AM
if not the catalist i think it may be the downstream 02 sensor
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Mike Pavelin on May 17, 2009, 11:39:08 AM
Most likely cause is upstream O2 sensor but the thing should run ok from cold even with the sensor shot to pieces as the PCM doesn't look at it until it's up to temperature.

BTW, when you say you ran it out of coolant, did it overheat? They have a habit of melting pistons when that happens. That'd sure make it run rough.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 17, 2009, 07:26:50 PM
Quote from: "Mike Pavelin"
Most likely cause is upstream O2 sensor but the thing should run ok from cold even with the sensor shot to pieces as the PCM doesn't look at it until it's up to temperature.

BTW, when you say you ran it out of coolant, did it overheat? They have a habit of melting pistons when that happens. That'd sure make it run rough.

where are the o2 sensors ? i've just read that its the lambda  :-)

the coolant tank [ expansion tank ? ] was empty when i first discovered the roughness, but the temp gauge was normal.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Tank on May 17, 2009, 08:13:14 PM
I thought Lambda and o2 sensor was the same thing.... :?:
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Panic mechanic! on May 17, 2009, 08:51:03 PM
they are,lambda sensors the geeky name for them
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Mike Pavelin on May 18, 2009, 07:31:59 AM
The O2/Oxygen/Lambda sensor you're looking for is in the front downpipe.

Do you have a regular misfire on one cylinder or random roughness? It might be worth doing a compression check before changing any more electrical bits.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 18, 2009, 07:23:44 PM
Quote from: "Mike Pavelin"
The O2/Oxygen/Lambda sensor you're looking for is in the front downpipe.

Do you have a regular misfire on one cylinder or random roughness? It might be worth doing a compression check before changing any more electrical bits.

i wouldnt know how to.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Bishops Finger on May 18, 2009, 09:58:49 PM
Not all of us do


Where are you based dude..?
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 19, 2009, 06:59:08 PM
suffolk
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Bishops Finger on May 19, 2009, 08:30:08 PM
FTE


Mansfield


Doc

???
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 20, 2009, 10:01:33 PM
ordered the lambda will fit this weekend.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 23, 2009, 08:02:31 AM
fitted the lambda, still not cured the problem. the lambda sensor was covered with black soot.

took it to mansfield 4x4 and they are puzzled, nothing has showed up in the codes.
and they cant look at it till tuesday.

could it be something simple like the auto chock is on ? or any of the fuses is blown
is there anything else that controls the air/fuel mixture ?

battery reading is ok / temp guage is ok / oil reading is ok .

????? thks
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Panic mechanic! on May 23, 2009, 08:09:08 AM
its normal for a lambda sensor to come out covered in carbon, the only other thing I can think it may be worth a look at is the cold start system, is there a cold start sensor thats died and the engine is always thinking its not warmed up.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: PtP on May 23, 2009, 05:46:08 PM
I’m surprised the O2 sensor didn’t resolve the problem.

Have you checked the air intake system is not blocked with something? What state is the air filter in?

The other things to consider are the MAF, TPS, CPS and the downstream O2 sensors. I think you can just unplug the first two (one at a time) and see if this makes a difference at tick-over. You will probably end up with the EML light on on the dash though.

Just my 2p worth!
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: PtP on May 23, 2009, 08:22:27 PM
Quote from: "bunnykins"
……the RAC cleaned the distributor before i changed all the above and it seemed to go fine for 20 mins……
I’ve just re-read the original post and there is also a camshaft position sensor in the distributor, could this be faulty or loose even?????

I bought a new O2 sensor recently for my TJ off ebay and some of the ebay sites explain the symptoms that their products will fix, so it might pay you to search on ebay for MAF, TPS etc. (not necessarily for Jeeps) and see what symptoms they describe each sensor will fix.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 24, 2009, 08:58:01 AM
Quote from: "PtP"
I’m surprised the O2 sensor didn’t resolve the problem.

Have you checked the air intake system is not blocked with something? What state is the air filter in?

The other things to consider are the MAF, TPS, CPS and the downstream O2 sensors. I think you can just unplug the first two (one at a time) and see if this makes a difference at tick-over. You will probably end up with the EML light on on the dash though.

Just my 2p worth!

its all too technical for me, whats MAF, TPS, CPS  ? thanks
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: PtP on May 24, 2009, 09:56:51 AM
Quote from: "bunnykins"
its all too technical for me, whats MAF, TPS, CPS  ? thanks
Here goes:

MAF – Mass Air Flow Sensor
http://motors.shop.ebay.co.uk/items/_W0 ... acat=14239 (http://motors.shop.ebay.co.uk/items/_W0QQ_dmptZUKQ5fCarsPartsQ5fVehiclesQ5fCarPartsQ5fSM?_nkw=maf&_sacat=14239&_trksid=p3286.m270.l1313&_odkw=&_osacat=14239" onclick="window.open(this.href);return false;)

TPS – Throttle Position Sensor
http://motors.shop.ebay.co.uk/items/_W0 ... acat=14239 (http://motors.shop.ebay.co.uk/items/_W0QQ_dmptZUKQ5fCarsPartsQ5fVehiclesQ5fCarPartsQ5fSM?_nkw=tps&_sacat=14239&_trksid=p3286.m270.l1313&_odkw=maf&_osacat=14239" onclick="window.open(this.href);return false;)

CPS – Crankshaft Position Sensor
http://motors.shop.ebay.co.uk/items/_W0 ... acat=14239 (http://motors.shop.ebay.co.uk/items/_W0QQ_dmptZUKQ5fCarsPartsQ5fVehiclesQ5fCarPartsQ5fSM?_nkw=tps&_sacat=14239&_trksid=p3286.m270.l1313&_odkw=maf&_osacat=14239" onclick="window.open(this.href);return false;)

Also, just put into google any of the above terms and you’ll plenty of information as to what each sensor does.
http://www.google.co.uk (http://www.google.co.uk" onclick="window.open(this.href);return false;)
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Mike Pavelin on May 24, 2009, 10:26:24 AM
I still say do compression check before wasting time and money on other stuff.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 29, 2009, 09:01:40 AM
the car has been in with mansfield 4x4 since 22.05.09 and they say there was no error code and the only thing they can find is a small hole
in the exhaust manifold. i have asked them to weld it but they say it may not work and advice me to buy a replacement manifold and prob 3
hours to fit. so i am not sure if they have done a compression check. they did say they did a reset [ not sure what ? ]on it after i changed
the lambda sensor.

why cant it be welded ? if it can, how long would that take to do ?

thanks
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Mike Pavelin on May 29, 2009, 09:13:01 AM
It may be weldable but is likeley to crack again and the labour time would be more as it has to be removed to get at the bit that cracks. Replacements are available for around £100. However, unless it is a huge hole it is not likeley to be causing your problem, there are plenty of 4.0 Jeeps running round with cracked exhaust manifolds (it's very common) with no porblem at all. Is the misfire a regular one on one cylinder only? if it is, I would still get a compression check done if nothing elese can be found. Computers are fine but they cannot see mechanical faults. It only takes 10 minutes and will eliminate a burnt valves, damaged piston, blown head gasket straight away.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on May 29, 2009, 10:42:48 PM
Quote from: "Mike Pavelin"
It may be weldable but is likeley to crack again and the labour time would be more as it has to be removed to get at the bit that cracks. Replacements are available for around £100. However, unless it is a huge hole it is not likeley to be causing your problem, there are plenty of 4.0 Jeeps running round with cracked exhaust manifolds (it's very common) with no porblem at all. Is the misfire a regular one on one cylinder only? if it is, I would still get a compression check done if nothing elese can be found. Computers are fine but they cannot see mechanical faults. It only takes 10 minutes and will eliminate a burnt valves, damaged piston, blown head gasket straight away.

i'll ring them tomorrow and ask them to do a compression check. i have not seen the hole so not sure how big/small it is. it not really a misfire, but a hesitation on accerelation or under load like going up a hill or when the autobox change down a gear. when i changed the plugs they were all covered with black soot like the front lambda sensor that i changed. hope they have also checked the after cat sensor.

thanks for taking the time to help out with feedback, much appreciated.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on June 09, 2009, 10:15:11 PM
got my jeep back today -  5 hours = labour 3 hours for the manifold and 2 for diagnostic.£270.00 i supplied the manifold.

not happy, it still seems rough and does not seem to be as quick or responsive as before, perhaps i need to give it time to run in ?

they carried out a compression test :
1=90psi
2=95psi
3=95psi
4=90psi
5=100psi
6=105psi
does this look ok ?

thks
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on June 12, 2009, 11:00:29 PM
well i took the jeep back today and mansfield put the old lambda back as a test. i drove it and within minutes it started to jerk about so i went back to
mansfield. i left the jeep there while they swap the bosch one back. they tested the old lambda and that definately dont work.

but the bosch one that i bought works fine ......... except it is running a little rough and does not seem to work well with the overdrive button switch off.
is it true that only the jeep ones will work 100% ? or is something else amiss ?

anyone know how much the jeep lambda is from the jeep stealers ? and is it cheap to buy from US ?

thks
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Bishops Finger on June 12, 2009, 11:40:19 PM
What did Mansfield think....
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: PtP on June 13, 2009, 11:32:50 PM
Quote from: "bunnykins"
........is it true that only the jeep ones will work 100% ? or is something else amiss ?..............
I've recently had a Bosch one fitted to my TJ and whilst the old one with hindsight was okay, the Bosch one seems to be working just fine.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Panic mechanic! on June 14, 2009, 08:47:34 PM
your jeep system is a bosch system from what i understand so it's the same.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Mike Pavelin on June 15, 2009, 07:27:17 AM
If you have been running with a faild lambda sensor for a while, have you considered that the cat could have partially melted inside due to over fuelling. Whis would create a restriction in the exhaust resulting in power loss and incorrect fuelling at higher revs.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: JamesH on June 15, 2009, 10:18:05 AM
New lambda from Jeep was £80+VAT for my XJ last month and new cat was £65+VAT & delivery from catsdirect.com
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins2 on July 03, 2009, 08:18:57 AM
If you have been running with a faild lambda sensor for a while, have you considered that the cat could have partially melted inside due to over fuelling. Whis would create a restriction in the exhaust resulting in power loss and incorrect fuelling at higher revs.

so i suppose the cat and the after cat sensor now have to be replaced ? is this normal ?

does the compression figures look healthy ?

thks
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins2 on July 03, 2009, 08:23:22 AM
does anyone know if the computer needs to be reset if you change/fit a diferrent lambda sensor ?
or do you just fit it and the computer will automatically work out the mixture and it will reset itself ?

i just had the jeep mot'd and it passed ! they found 2 screws loose on the new manifold that was fitted
and tightened them up which may affect the mixture ?

thanks
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Mike Pavelin on July 03, 2009, 08:10:09 PM
It will relearn itself eventually.
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on August 09, 2009, 08:32:48 AM
thanks for all the feedback.

well i am not totally happy since my jeep came back from mansfield, as its not running as smooth as before it went in,
despite them saying i needed a new manifold and the sensor. they havent replied to my email or shown any interest in
helping me sort this out.....they were happy to take the money !

i replace the leads,distributor/rotor/plugs with all new. i have heard that some leads will not work as well as the oem
stuff, has anyone had this ? i feel like putting the old leads back to see if its that.

any ideas are welcomed.

 

Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: Bubba on August 09, 2009, 11:03:23 AM
leads can and indeed do  breake down
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on August 10, 2009, 10:10:57 PM
leads can and indeed do  breake down

do you mean the old or the new ones ?
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: daggie on August 12, 2009, 06:55:51 PM
where abouts are you BK??
Title: Re: jeep grand cherokee:Running rough and strong smell of petrol
Post by: bunnykins on August 15, 2009, 01:05:31 AM
where abouts are you BK??
suffolk