2005 LC suddenly even worse gas mileage.. (2 Viewers)

[KissinKate]

Hi, my beloved has gone from its majestic 14.9 mpg to 11.. I was hoping someone here might be able to tell me where I might take him to recieve whatever treatment might be needed. I ride dirtbikes so I'm often on dirt roads and maybe that has something to do with like the air filter? Excuse my ignorance as I have no mechanical skills..

Thanks!

 

[NMBound]

Go to Chris at Toyomasters. He's a good guy.

 

[KissinKate]

I will do that. Thank you

 

[Mauser]

Should've gone to the meeting this morning. All you have to do is pop your hood and you get 14 guys standing around. Its a helluva way to find out where to start.

 

[pappy]

Off the wall, I'm guessing the check engine light isn't on. You might for chuckles go see if there are any stored codes.

 

[slimbuddha]

Have you made any changes to the vehicle recently?

 

[KissinKate]

Have you made any changes to the vehicle recently?

I haven't. It also seems a bit underpowered, normally, driving I 40 to Tijeras, even with my dirtbike on the back I could accelerate, it'd drop down and go. Today I accelerated and it didn't shift down and go, just seemed to stay in the higher gear forever. This saddens me.

 

[SteveLCetc]

Is it the same in cruise control?

 

[pappy]

I haven't. It also seems a bit underpowered, normally, driving I 40 to Tijeras, even with my dirtbike on the back I could accelerate, it'd drop down and go. Today I accelerated and it didn't shift down and go, just seemed to stay in the higher gear forever. This saddens me.

I would start with an air filter. The engine sounds like it's choking.

 

[SteveLCetc]

"Suddenly" doesn't sound like an air filter though. I agree check for stored codes.

 

[slimbuddha]

My guess, you are about to lose a coil pack. Check for engine codes & the air filter like others have said. The coil pack going out can cause misfires, but it has to exceed a certain number of the in a minute before the check engine light comes on

 

[Mauser]

Techstream is the best tool you can own if you have a 100 series. An old laptop running XP, a $25 mvci cable, and a little bit of time is all it takes to get it up and running.

 

[empty80]

I’d be inclined to have a look at the PCV. Those jokers can stick abruptly and wreak havoc on fuel economy without any further symptoms.

 

[KissinKate]

Is it the same in cruise control?

What an interesting question! I honestly don't know. I can't remember the last time I used the cruise control. I will try that today.

 

[Dumpolina]

tire pressure?

 

[marcfj60]

Techstream is the best tool you can own if you have a 100 series. An old laptop running XP, a $25 mvci cable, and a little bit of time is all it takes to get it up and running.

The second best thing to having Techstream is knowing somebody with it that will meet you in the parking lot of a gas station to help you diagnose stuff.

 

[NMBound]

My guess, you are about to lose a coil pack. Check for engine codes & the air filter like others have said. The coil pack going out can cause misfires, but it has to exceed a certain number of the in a minute before the check engine light comes on

I think I may be having an ignition coil going bad. On our trip last weekend we got barely 14 mpg on the way to San Diego and barely 16 on the way back. I'm not sure if that's because we were going uphill from 2500 to 4000 feet the whole way there or what. We're used to a comfortable 17 mpg when cruising at 70 mph.

In the middle of the city area we lost power for a split second while I was driving. I felt it in the engine, climate control, and audio all at the same time. Pulled into Autozone immediately after and found no codes. I'm guessing that I may be dealing with some misfires and one was particularly bad.

 

[slimbuddha]

I think I may be having an ignition coil going bad. On our trip last weekend we got barely 14 mpg on the way to San Diego and barely 16 on the way back. I'm not sure if that's because we were going uphill from 2500 to 4000 feet the whole way there or what. We're used to a comfortable 17 mpg when cruising at 70 mph.

I think the elevation changes play a big part in that, as well as the wind across AZ. I've taken that route in the LC and the only way I got decent mileage was dropping to 70 like you did, and disabling the cruise control on elevation changes.

 

[alia176]

I think I may be having an ignition coil going bad. On our trip last weekend we got barely 14 mpg on the way to San Diego and barely 16 on the way back. I'm not sure if that's because we were going uphill from 2500 to 4000 feet the whole way there or what. We're used to a comfortable 17 mpg when cruising at 70 mph.

In the middle of the city area we lost power for a split second while I was driving. I felt it in the engine, climate control, and audio all at the same time. Pulled into Autozone immediately after and found no codes. I'm guessing that I may be dealing with some misfires and one was particularly bad.

When you head West, you're going against the jet stream so basically a head wind the whole time. Funny thing is that you were also losing elevation which is easier on the engine. Apparently, air drag over powered elevation loss!

Firstly, I'd check all vac hoses or simply replace them all if the ends are split/cracked. Secondly, check fuel pressure and this one is a tough one. Unless you're driving around with the test gauge taped to your windshield, and this hiccup occurs at the same time, it's hard to detect fuel issues easily.

 

[Mauser]

Firstly, I'd check all vac hoses or simply replace them all if the ends are split/cracked. Secondly, check fuel pressure and this one is a tough one. Unless you're driving around with the test gauge taped to your windshield, and this hiccup occurs at the same time, it's hard to detect fuel issues easily.

I agree with this. I bought a smoke machine and tested it out on my LX. I was surprised by how many of my connections and hoses were leaking just a tiny bit.

You might be able to use Techstream for fuel pressure. I don't know though, but checking fuel trims can also tell you a lot.