Hi Guys, I am looking for some help with a 04 Discovery SE 86,000 miles that I just purchased. This is a little lengthy but I am going to try and explain so that there are not too many questions. When I purchased the vehicle the service engine light was on. I scanned it before purchase and found codes for O2 sensor, misfire and lean codes. It would not down shift to the next gear unless you really floored it and maybe not always. It would also not start on the first try ever, always the second try. Being optimistic I thought a full tune up and this stuff should go away. So I purchased the truck and the following items. Magnacore wires, Platinum 4 plugs, Denso O2 sensor, plenum gasket, seafoam, air filter, Oil filter and Rotella oil. Over a few different days I have changed this entire out. I tested the coil and it had the correct resistances. I finished everything except the O2 sensor first. It cleared the codes except for lean code and O2 code for bank 1. It ran ok but would “pop” thru the intake when I got on it. I did a homemade smoke test for the lean codes using “The Smoking Gun” (for the food service industry. It worked great and the garage smelled like hickory smoke) and the only place I have any smoke coming out is the little tab on top of the intake just behind the MAF sensor about 2 inches. Looking at that part it looks like air should be able to come in or out of there. So I don’t think I have a vacuum leak. So I put on the new 02 sensor and used Seafoam in fuel and engine. Well now it’s not happy at all. I drove it a few miles and let it idle for a bit. Now it won’t idle well, flashing SES light, put it in gear and I might be able to “two foot” it into the garage from the driveway. I believe the MAF is working because I have tried disconnecting it and the vehicle won’t start at all. So over the last two days I have been looking around the blogs here on The Land Rover Forum and I am convinced that I have the rarest form of the wildebeest flu that is only found in Africa. I haven’t been there so I must have picked it up and somehow passed it along to the Rover and that is why it is acting this way. Or maybe it’s just a Rover and it has nothing to do with me. Hmmm. Something else I should mention is that I noticed a ticky ticky noise only after it warms up. Never on start up. From what I have read maybe that is slipped sleeve? I also noticed that the coolant was low when I purchased the truck so I put in about 3 quarts. No obvious leaks on the ground and I have only driven it about 6 or 8 miles at the most so I can’t tell if it is using it. So today I did a compression check and 6 cylinders are at about 170 and 2 are about 160. The current codes are Misfire codes. Any suggestions where I should look next?

 

If it got worse after the tune-up, I would double check your firing order/plug wire numbering. Very easy to cross them up that ignition system. If its two cylinders misfiring then that would be even more evidence toward that theory as well. I know its a pain to see back in there especially if its an air injected truck...but you can work that tube out of there if you have to w/o removing the intake to see the wires.

 

Thanks Rovertech1. I went ahead and checked this again tonight. I removed the plenum again because I was thinking it may of been possible I damaged the gasket when I installed it the first time and that it may be causing the lean codes due to vacunm leak. It appears to be good. All of the wires are lined up to the diagram that I found on one of the threads here. It matched the first time. I dont see a firing order/ coil diagram in the Rave manual? since I have it apart I think I may get a coil, gasket and MAF just to be sure. I really hate throwing parts at it. Any other thoughts guys?

 

Coil diagram is on p. 379 of my RAVE PDF.

 

Hello All. I installed new coil, MAF and intake gasket. Ran exactly the same. Like Crap. Still miss fire codes and lean code. The only thing I had not checked was the Fuel Pressure. I did not own a gauge and thought it was kind of either I have fuel or I dont. Well I was wrong. Bought a gauge and found out it had 20psi of pressure (should be about 50psi) and would not hold any pressure once the key was off. This is why it would never start on the first try. It needed to build up pressure again. Looking back I should have started with a fuel pressure check because of that reason. Oh Well. I ordered a new pump from carpartswholesale on eBay for $62.00. It arrived today and I installed it right away. 50PSI and runs like a top! Im glad its up and running just in time for our wonderful Northeast snow.