It appears that to own a grand Cherokee Lerado 1999 you need a wallet with unlimited funds available from it. I will explain the symptoms however it is bit long winded.
Driving to work 14km, approximately half way several Phone cell towers installed recently, coincidental I am not sure.
Around this half way point, the car often, but not every time, hesitates momentarily then keep going, at first always in the same area. I was at one time convinced it was electrical interference from these new cell towers.
Progressively the problem got worse, and the hesitations became more like loss of power for short intervals, again around the same area, but gradually further afield.
I need to say most of these hesitations happened while driving along and as I was still moving the motor fired back into life and kept going.
Last week it happened again this time it was worse, the fuel gauge went to empty from around half a tank reading, as the motor died completely, I restarted the engine and drove to a service station and fuelled up, it started up fine after that started to leave the service station and it died, started up again and drove off only to break down just half a kilometre further down the road. From there it refused to start for around three quarters of an hour, finally it started and I managed to get to work with several motor hesitations along the way.
Now I have removed the fuel tank replaced the fuel filter pressure regulator and cleaned the fuel tank. Note! I also removed the anti siphon, because I could not drain the tank, had to lift the tank out full of fuel, Checked the pump and appeared to work fine. The pump has signs of rust and found rust particles in the bottom of the tank.
Engine now starts better than it ever has.
However I am now back to the motor hesitation around those cell towers again. Potential electrical interference related issue???? Still not sure.
Drove to work not fault found, believed the problem was fixed. On the drive home after work motor hesitated around three times first time around those pesky cell towers and two times a bit further down the road.
Now My Cherokee is having a holiday sitting in its garage at home, not game to drive it any more.
I am like a dog with a fresh bone and find it difficult to let go of a problem that is bothering me.
So day 4 of working on my Cherokee.
today Monday 9th of november 2010
After work decided to follow up on some research
Checked the computer and connections totally removed it removed all screws ant tried to get inside, Hmmm, glued shut.
Prised the sides open and found the circuit board is glued to one side and components are through to the other side is very difficult to open without destroying it. Re assembled the unit and reinstalled, still works fine not serviceable.
Regarding assembly screws touching the circuit board, (as per a post found on this site) on unit not possible no screws are mounted anywhere near the circuit board .
Looked for potential loose plugs (as per post found on this site) again on this unit while motor was running I jiggled pocked probed and the only time the motor stopped was when I actually un plugged a socket.
Being the motor was already warm I decided to try to duplicate the problem.
Whit foot on Brake HARD I selected forward and reverse several times even increased the revs to no avail.
Last I placed the car back into park and held the revs at 1800 to 2000 rpm like at highway speed. Was about to give up and with great excitement the motor died! I know this is not the solution but I have found that the problem is now repeatable. Motor temp was 100 according to the in car gauge, as for any check engine light coming on or other instrumentation malfunction nothing before it actually stalled at which time the Check engine light illuminated. So now I will go further and do more tests to find a suitable solution.
OK today day 5 after work I got my OBDII reader working and did the tests again to discover when the motor stalls, no error codes are recorded, this leads me to believe it is most likely the fuel pump, so looks like I will spend this weekend replacing it.
Well I priced the fuel pump from Chrysler dealership today I was flabagasted to hear the price wa $758.00 Australian, needles to say I borked at that. so doing some research I found out that the pump used in holdend of that era were exactly the same, so I priced a vn fuel pump, Priced at $248.00 Australian, not bad I thought, but not convinced it was still a good deal, rang around and low and behold I found a new VN High pressure fuel pump for $97.00 Australian. now that sounded like the pump for me, the best part is the supplier has one in stock and is opend on both Saturday and Sunday, best of all is I will have time to remove my pump and compare it to the VN pump before I spend any money. so guess what I am doing this weekend.
After talking to other owners of various Jeep models the fuel pumps tend to overheat then shut down when ageing, shutting down is a good thing considering where the pump is, honestly the last thing you want is for your fuel pump to keep getting hotter or to ignition point. The only thing I will say is why on earth do manufactures insist on supplying cars with no access port preventing access to the fuel pump.
In older cars to service components in your fuel tank there was a bolt on cover plate when removed gave access and serviceability.
Final installement on this post I hope!
Fuel pump replacement did improve over all status; however the Crank Position sensor fixed the problem, well at least so far.
both were very involved it replacing, however after manufacturing a 3 foot 1/4" drive extension and a lot of hard work the Sensor was finally in place, it took about 4 hours to complete, including making the additional tool required, I could only gain access by way of lowering the passenger side of the gearbox cross member and loosening the driver’s side to prevent bending it, while supported on a height adjustable stand.
And yes the 3 cycle key on of test showed error codes until the parts were replaced and codes were cleared. Now the waiting game begins but so far so good.
Throttle body will be coming of this weekend to service and clean.
Potential fix to stall problem found through net searches
Fuel pump, pressure test, replace if required
Cam shaft positions sensor, check and replace if required
EGR valve, check and replace if required
PCV valve and supply tube must be clean and clear, check and replace if required
The outboard PCM cover screw may be shorting out the circuit board. Or plugs may be loose causing motor to stop when plugs wriggled, check adjust or replace if required. Only buy fully remanufactured computers not refurbished.
Crank shaft position Sensor, check and replace if required.
Hopefully this situation will be resolved soon.
One last method of fixing the problem is very simple and in need of serious consideration.
SELL CHEROKEE. BUY NISSAN X-TRAIL or similar, Based on internet research and discussions with trusted mechanic (Note! he refuses to work on my Jeep Cherokee and any Kia’s his words ”ELECTRICAL NIGHTMARE”)
His recommendations for 4X4 are Nissan or Toyota in that order based on reliability and frequency of need for major mechanical and electrical problem solving.
FAQ
Search
Profile
Private Messages
Log in
