Ok here is the situation, 98 Disco with 170k miles on it. Started idling high so I cleaned the throttle body and Air Intake, Cleaned the MAF put it all together and it helped a little. Now it threw the code for misfire see Manuf. which by reading on other posts the answer is to change plugs and wires which I did. Unfortunately it is WORSE!!! it sputters, stays running as long as in park but once in gear drops down on the rpms and dies. I need help.

 

What is the actual codes you are getting? Are you sure you got the wires on correct?

 

Ok so the supposedly pre gapped plugs, weren't and the numbering order on which side was even and which side was odd for putting the wires back on was backward. Anyway, got it done running fine now just idling high and I ordered an new air intake valve as that is hopefully the only problem. This weekend......fuel filter and engine cleaning, should be fun.

Thanks for the help.

Walter

 

Never assume that the spark plugs are gapped correctly.
The same spark plugs that fit your engine also fit countless others and they may have a different plug gap than you.

 

Ok so I got the new air intake valve in and changed it, cleaned the MAF and still Idling high. Not going up and down just idling high about 2500 then about 1200 when in gear. Any help would be appreciated.

 

You've got a vacuum leak somewhere. Trace all your vacuum lines and check them for cracks. And quit cleaning your MAF before you kill it and cause more problems. The MAFs on these trucks are pretty sensitive and don't take cleaning well.

 

I had the same problem and like AK stated I found a vacuum hose that was off.

 

Vacuum hoses first....they are easy/cheap to replace. Mine were original and needed it. The one from the right side rocker cover to the ram housing gets a nice little crack in it that is common. My particular issue was the Throttle Position Sensor (TPS) broke. Inside there are 2 triangle shaped 'stoppers'. One side broke. When this happened, the vehicle tried to compensate which led to High RPMs. Once I repaired the broken piece (with superglue) there was too much glue residue and the TPS seated a bit off which led to Higher RPMs. This put the voltage reading at twice the approriate amount and the vehicle assumed I had my foot on the throttle and did not compensate. I shaved the TPS down until the voltage read properly and the vehicle compensated. All that being said, I have a great friend at a Land Rover Centre and he hooked up to the testbook so I could read the voltages as we repaired the TPS. The TPS is easy to take off and see what I explained. Good luck.

 

Mine seemed like it was fixed with vacuum hoses, but then it started idling really low (400rpm). I'm going to try to clean the throttle body, and the IAC, and see if that works.