Misfiring - '98 Discovery I

[mac1410]

I have a 1998 Discovery I with 95,000 miles. It started to misfire, sputter and the check engine light came on so I took it into the shop and I was told that I was in need of a major tune-up, the Cam Shaft Sensor needed to be replaced and also the Catalytic Converter had failed and needed to be replaced. I am ok with that, but my question is if I give it a major tune-up and replace the sensor do I need to change the Cat right away? Or will it still misfire with the old Cat in place? The Cat is not a cheap part in California. Any advise would be great. Thanks!

 

[discomike]

So how mechanical are you, do you want to be walked thru a good major?
Start with a good set of plug wires, plugs and some great fuel and oil additivies and see how it runs, you may not need the cats and if you do I have a few good places for inexpensive cats.
You will need to flush the crank case, get alot of sludge build up out of there, then 3 cans of SeaFoam or some of B&G's additivies. When the tune is done, engine flushed and additives installed, go give it a good drive.
Mike J.

 

[mac1410]

I'm pretty mechanical. I done plenty of minor tune-ups, but never a major one and any tips would be appreciated. Do you know what the Cam shaft sensor does?

 

[discomike]

I would suggest you get a set of 8mm. Magnacor plug wires or their equivilant, a set of Bosh Platium Plus 4 spark plugs, a quart of good engine flush for the crank case and if you can find it 3 bottles of SeaFoam, Napa has it and of course an air filter. Of course some good oil and plan on changing it a second time between 1000 and 1500 miles.
Hoses, belts and other parts of a major come second.
You are still looking at servicing the t/case, diffs,tranny, flush the radiator, change the power steering fluid and complete brake flush.
The cam position sensor is just that, it tracks the position of the cam and revolutions, lets don't worry about it yet, first things first. When do you think you are going to want to start this project?
We should talk on the phone before to make sure there are no problems.
Mike J.

 

[mac1410]

This weekend I changed the sensor, plugs, wires, air filter, fuel filter, belt, & hoses. I flushed the radiator and boy it was dirty. Next step is to flush the engine and change the oil. I was doing some reading on SeaFoam this weekend, How much and where do you recommend to put it in? Gas Tank? Crank case? Thanks. Marcus

 

[frankvega93]

i think if you measure with ohms meter if its over 1000 replace it if not dont change it normoly if the spark have it gap correct no problem some time when you buy sparkplug they fall or miss handle check gap also best tuning