[HondaGirl93]

I have a 2006 Honda Ridgeline RTS with 176,XXX miles on it. I bought the truck in May and noticed it took just a touch longer to start than most vehicles I had driven but didn't think anything of it. Recently I have noticed not only a dramatic decrease in mileage (used to get 15-17 around town, now down to 12-14) but also that sometimes the truck barely starts! The remote starter will not start it after 3-4 tries, and when turning the key physically it will crank for 25-30 seconds before catching and starting up.

The mileage is NOT due to the cold weather, as this began prior to the temperature fluctuations here in Boston. I always fill up at Top Tier stations, but have switched it up every so often to see if it helps the mileage. I have also tried using premium and it has not helped.
The dealership inspection turned up nothing, the ECU is throwing no codes.

Recent work includes...

• Timing belt replacement
• Brake Inspection
• Removal/Inspection of Fuel Pump and Cleaned Filter
• Transmission Fluid Change
• Engine Oil change every 5-7k w/ Mobile1 Synthetic
• VTM-4 Fluid Change
• Injector Compression Test (Holds Fine)
• Spark Plug(s) Replacement
• Alignment/Balancing of tires
• Intake/Exhaust Valve Adjustment
• Water Pump Replacement
• Air filter replacement w/ K&N washable

 

[eurban]

Did your drop in mileage drop / hard starting begin after the major service (timing belt / water pump / valve adjustment)?

If so they might have messed something up like timing off a tooth, valves improperly adjusted etc etc.

 

[Ourfarm09]

[*]Air filter replacement w/ K&N washable
[/LIST]

Just the filter element or the complete filter assembly?

 

[Dnick]

You could have a cylinder not firing ("missing"), but I'd bet you've got 'bad' injectors; as in leaky & maybe bad spray pattern to boot. The leaky injectors would partially flood one or more cylinders, causing the slow start-up. And the bad injector performance (spray) could certainly hurt your gas mileage.

 

[HondaGirl93]

The issues were all prior to any work being done, most of the work I did was usual maintenance and trying to figure out why the mileage has been so awful.

Just the filter element was replaced, didn't see any reason to change the housing.

Dnick, this is what I think it is most likely to be. Next on the list is a compression check, a leak down test, and if all that checks out ok replacing the injectors. It has, however, never miss-fired or idled roughly, once it's running it is very smooth and powerful...which is part of the reason I'm so confused.

 

[IanRTL]

The issues were all prior to any work being done, most of the work I did was usual maintenance and trying to figure out why the mileage has been so awful.

Just the filter element was replaced, didn't see any reason to change the housing.

Dnick, this is what I think it is most likely to be. Next on the list is a compression check, a leak down test, and if all that checks out ok replacing the injectors. It has, however, never miss-fired or idled roughly, once it's running it is very smooth and powerful...which is part of the reason I'm so confused.

I'm not a huge fan of the oiled K&N filters. They're overly expensive and don't filter as well as a stock-style paper filter. You don't see any performance gains or anything like that, either. I doubt that has much of anything to do with your issue, though. I wouldn't hesitate to say that it's fuel related. Either clogged injectors or maybe a failing fuel pump? The pump itself is integral to the fuel tank and it's only able to be accessed through a small panel in the floor behind the rear seat. I would also try turning the key to the "on" position for about 3-4 seconds before you try cranking in order to allow the fuel pump to fully prime.

What octane gas are you using? If only 87, try running a few tanks of premium through it and add a bottle of good fuel injector cleaner. I use Seafoam every now and then, but any other quality product like Chevron's Techron will work. If your injectors are too clogged to be able to be cleaned with a liquid additive, it's likely not a bad idea to take them out and clean them. Or, if they're not too expensive, replace them altogether. With that many miles, deposits are bound to have gotten stuck in them over the years.

 

[HondaGirl93]

I ran Seafoam and several tanks of premium through the truck, the fuel filter in the tank is clean.
I'm thinking injectors next :/ unfortunately, I have read several posts though where this issue remains a mystery after replacing the injectors.

 

[IanRTL]

How about your O2 sensors and catalytic converters? To replace all four of the O2 sensors in this truck is a bit expensive depending on where you buy the parts, but if those are gummed up and not working well, they could absolutely cause the mileage problem. I'm not certain if it would cause the starting issue or not, but it certainly does sound like it's fuel related. What are your typical driving patterns? Lots of short trips and sitting in traffic? Moderate distance on 2-lane roads? Highway driving? Do you "get on the gas" periodically to get the truck over 4000RPM? Lastly, have you ever done an Idle Learn Procedure to reset all of the stored fuel curves/whatnot? If not, I'd look up the procedure and do it asap.

 

[Dnick]

I ran Seafoam and several tanks of premium through the truck, the fuel filter in the tank is clean.
I'm thinking injectors next :/ unfortunately, I have read several posts though where this issue remains a mystery after replacing the injectors.

Hey HG,
Sorry this didn't occur to me before to mention; but your symptoms are not a mismatch for injector problem, presuming the injector problem is actually just bad o-ring(s). You could be getting by-pass leakage while sitting (not running), as pressure in the system pushes fuel past a bad o-ring (or more) & drips into intake. This would cause hard starting ("flooding" condition), while causing no ill effects once the engine is running.
I had a carburetor analogy version of this once with a Camaro that had a porous casting in the area of the fuel bowl.... it leaked fuel into the manifold when I was stopped for moderate periods of time (1/2 to 2 hours), and would not start when I came back (flooded). If it was just 5 minutes, or if it was several hours or overnight, it would be just fine (fuel either did not have time to leak enough out, or had enough time to evaporate away.
It took them forever to figure that one out (them being dealer service dept.... it was a brand new '82 Z28) .

Maybe you have similar effect from leaky o-rings on your injectors. Try replacing those first (before the entire injector). Like you said, if it's running fine, then the "performance end" of the injector is probably just fine. Check it out! (be sure to let us know what you find in any regard)


P.S. If it turns out to be bad o-rings (especially if more than 1), you might want to revisit what you're putting in your fuel tank... you could be degrading these seals chemically.

 

[skelley521]

Once running, does the motor run rough?

You can unplug each ignition coil and feel the motor. When you unplug one, it should get slightly worse by feel. Plug back in and try the next one until you pull one and notice no change. That is usually the bad coil.

Here's a vid to help:
https://www.youtube.com/watch?v=t15SwWHRZx8

Normally I would say a "hard or no start" condition is a crank position sensor.

Problems like this take time and trouble shooting each step as many things need to be eliminated.

Edit: I hate those oil sprayed air filters. They suck oil out over time and usually cause problems especially w/ sensors.

 

[larryr]

My guess is they never replaced the spark plugs on the 100,000 mark, from ones that Csimo had from his 100,000 job, they looked almost new, but I suspect that they could last another 50-70,000 more miles before acting up.

My 2 cents is get rid of the K&N Air filter - you can get good air filters on e-bay in the $6 range with shipping. (you have to buy a few to do that).

 

[Carsmak]

I agree with getting rid of the K&N filter atleast while troubleshooting. The oil can severely affect the Mass Air Flow sensor. Also once removed find & clean the MAF.

EDIT: I always thought we had MAF & that was why everyone saw issues with the various Cold Air Intake kits.

 

[speedlever]

There is no MAF sensor on 2006-2008 RLs. The 2009 RL is the first model year using the MAF. Interestingly enough, Honda uses both MAF and MAP sensors beginning with the 2009 model year.

 

[Elkhunter]

That COULD make finding the MAF sensor somewhat problematic...

 

[speedlever]

Not really.

 

[speedlever]

EDIT: I always thought we had MAF & that was why everyone saw issues with the various Cold Air Intake kits.

That may have something to do with the fact that K&N does not offer a 57 or 77 series intake kit for 2009 and up.

 

[Dnick]

There is no MAF sensor on 2006-2008 RLs. The 2009 RL is the first model year using the MAF. Interestingly enough, Honda uses both MAF and MAP sensors beginning with the 2009 model year.

That COULD make finding the MAF sensor somewhat problematic...

Not really.

You usually don't miss the tongue-in-cheek Speed, but in this case...
He was talking about the 2006-2008! :act060::act024: