I have a 1998 Disco with 125,000 miles. The engine has a rough idle but accelerates fine.. I replaced the plugs, wires, pvc hoses, fuel filter, fuel pump, o2 sensors (4).. I think that was it.. The o2's were bad for a while (maybe 10,000 miles)... I think my cats are bad now due to the rich fuel mixture but I want to make sure its them before I spend 700.00 on them... I checked the vacuum and its at 14-16lbs then I hit the gas and it goes to 18 lbs.. Is thispressure or normal?? I 've also read that a k&n can cause a mass airflow sensor go bad so I will be tossing that out soon.. I also want to make sure its not the mass air sensor.. Thanks for all your help...Scott

 

Do you have any fault codes? Vacuum sounds normal at idle, I am not sure if 18 is correct when you hit the gas. What octane gas are you using?
Mike

 

Yeah the CEL light is on and it says p1178, p1187 and there was one more (can't remember code) it was for a cylendar 7 misfire... That's whenI got the new plug wires.. The scnner at auto zone said that its wasair/fuel mixture and that was it. I fugred that the codes were related due to the misfire.... I am running the cheap stuff (87) with the lucas additive once a month.. Do you know if I can use the aftermarket cats and weld them in or is there something special about the land rover ones. I do have the o2 in front and behind that cats....

 

First, you can't run 87 octane in a Rover and get away with it, it will carbon up your engine, run like crap and get terrible gas mileage. By the way, I use Lucas and it is being waisted on the 87 octane.
So have you replaced your 02 sensors yet, if not they need to be replaced. I would also look for a bad vaccum leak.
Mike
P1177 Maximum Negative FMFR Correction Fault
P1178 Maximum Positive AMFR Correction Fault
P1179 Maximum Negative AMFR Correction Fault
P1185 Oxygen Sensor Heater Circuit Open Upstream
P1186 Oxygen Sensor Heater Circuit Short Upstream
P1187 Oxygen Sensor Heater Circuit Short Upstream

 

I'll step up the octane... I replaced all 02 sensors about4 months ago... What dose (P1187 Oxygen Sensor Heater Circuit Short Upstream ) mean?? I will take a look at all the vacuum lines and the plenum tonight... I'll also take the rover back to auto zone and have it ran on the scanner again...
Scott

 

I would contact the store that sold you the 02 sensor, tell them of your code and get it replaced.
Mike

 

I was wondering if the rocker arms are adjustable? I am hearing a little tapping noise all the time.. I took the rover to autozone and it showed the same codes as before.. They cleared the codes and the parts guy mentioned that the 02 sensors are working... I hope the light dosn't come back on.. oh yeah BTW I put in 91 this morning..

 

It will take a good engine flush, induction cleaning and alot of good additive to clean up your carbon.
No the rockers are not adjustable. I would suggest you call me and lets get you going on a good flush before you have to replace the rockers and or lifters .
Mike
303-862-7680

 

I'd like to get in on the info on a good flush. Thanks mike!

 

If you do your own oil changes then you can do this.
Buy 6 qts of ATF, drain your engine, replace the oil with the ATF, start the engine and let it idle for at least 20 minutes, no driving with the ATF in the engine. When this is done, drain the ATF, change your filter and add your oil.
What oil and filter do you usually use?
Mike