95 Disco I w/ 154k. Did the ATF flush last night and can tell some difference in the smoothness of the engine as well as the quietness, I deem this a success. The one thing that seemed to worsen is the muted type backfires I get around 1500 rpm, there are now more of them and they even stretch into highway driving. In the last week I have performed the seafoam induction, seafoam in the tank and the ATF flush with plugs/wires/cap/rotor switch hopefully this weekend. i am still confident the new plugs et al, will solve this issue as well as the misfiring. My question, is it just a coincidence that the backfiring occurred more after the ATF flush than before? Again the smoothness and quietness of the vehicle has improved and the engine almost feels lighter when you accelerate, but the backfiring did increase at the same time. Just curious, I don't get a lot of time to work on the old girl so any help would be appreciated if anybody thinks I am missing something or heading down the wrong path.

 

What plugs and wires are you going with? I strongly suggest the Magnacor 8MM wires and Bosch +4 plugs... They really make a difference, and after the induction cleaning, you may have some bad plugs.

 

New plugs and wires will 99% sure get rid of the misfires. X2 on magnacors. I have Bosch Fusions in right now. They work fine, but I'm putting in Autolite coppers today. Just because I heard copper conducts better. I'm still keeping my Fusion plugs since they're new.

 

The misfiring happened about 50k ago and you are right the new plugs/wires/cap/rotor solved that issue. The backfiring has me a little concerned because that is a new phenomenon that hadn't occurred leading up to the prior plug and wire chage.

 

You may have a timing issues or worse yet a burned valve.

 

when do they happen, under acceleration, steady driving, or when you decelerate? Have you checked for exhaust leaks?

The new plugs and wires will change the burn of your cycle, making the O2 sensors ready differently, causing your mixture to change. That could have something to do with it, but you have another problem causing it..

 

What does a burned valve necessitate? Expensive? That should show up through a compression test right? Thanks for the help.

 

A little update...right after I responded to Mike my neighbor calls me. He's a good ol' boy that loves his mama and Budwiser and who i told terrorists taste just like chicken, so he's always on the look-out. Anyway I left the Rover home today and walked to work. Good ol' boy is at home and after hanging with me last night drinking beer doing the ATF flush and changing the oil, I told him I was still having trouble. So anyway he's home today and starts looking at the Rover (I didn't ask him to do this mind you, he just needed something to do). He just calls me at work and tells me the compression checks out fine and I think you may have a timing issue because "I found your timing advancehose laying right here on this here belt." Anyway I think my red neck neighbor just saved me a bunch of money and I'll get home and the plugs will all ready be out!

 

That's a great neighbor to have... definitely worth a half rack....

 

Bingo!!!