Hi
I have a 96 Jeep Cherokee Limited with 160k's on the clock and have been having some very strange problems recently. The message is long
- so sorry about that but I have included quite a bit of detail...
Many thanks in advance!!! Jon
- Heading up a reasonably long (flat) steep winding hill (1-2 hrs of driving). The car starts to loose power when putting my foot on the gas pedle, I was able to back of the gas a little but continued to loose power. I had to stop for 30 minutes as I had no power whatsoever and then try again - all seemed ok then after 15 minutes on a flat highway the problem starts again. I took the car back into town and put it in for a service - the guys replaced a very dirty fuel filter.
- Next day - Some as above - 1.5hrs of steep-ish windy roads the car does exactly the same thing - starts to fail up hill, I turn around and have the same problems returning to the garage even on the flats. I am constantly loosing power and getting slower and slower (average driving speed 110kph down to 10kph).
- Back to the garage and put a pressure gauge on the schrader valve on the fuel rail. Take the car out the next day on the same run and sure enough the same problem. I can see the fuel presure for the first hour is fine then it starts to drop - the further I go the more radical the drops in presure (for example 45PSI to 15 PSI on a quick pump of the gas). At some points the guage reads zero (0) PSI. Also while the car is failing and the guage is showing 0psi if the gas pedle is held flat to the floor the car will backfire
- Back to the garage, we replace the fuel pump (just the motor not the entire plastic housing) in the petrol tank (the fuel tank is plastic) and clean the filter in the tank.
- I drive 3,000k's (about 2200 miles) with no problems, yesterday I drive up a short steep incline then onto flat highway, about 45 minutes on the highway I start getting the same problems of loosing power
The mechanic has no idea what the problem could be and I have no ideas either. So I was hoping someone with a Jeep may have heard of this problem or may know where I can get further information or technical expertise. I'm based in Australia if that helps.
My summary for failing is the following :-
- driving up hill, possibly steep and winding - 1.5 to 2hrs of driving are required before failure - fuel pressure constantly drops after this - however driving can continue by watching the fuel pressure and only accelerating when it has returned to the correct presure (interestingly when driving at the begining put your foot flat to the will move the fuel pressure guage down as low as around 20-25psi, however the pressure recovery is very quick, after having the problems correct fuel pressure recovery may take between 30seconds to 5 minutes) - outside temperature are around 27-35 degrees celcius
Cheers! jON