I have a 2009 Fit Sport Automatic with 173k miles on it. On the highway today, I suddenly lost all acceleration - it felt like the car just went into neutral and if I stepped on the gas, I just got high revs/RPMs with no acceleration - the car did not lose electrical or any other power, brakes worked fine, I had about 3/4 tank of fuel. I managed to pull over to the shoulder and get the flashers on, verified that I was in Drive and not Neutral, placed the car in Park and then shut off the car. I restarted the car, put it in Drive and then was able to drive again without any problem and full acceleration power.

This is the second time this has happened - the first time was a couple three months ago and I disregarded it as a fluke. Since then, the car has driven fine until today, but I'm not comfortable taking it on the road since this behavior has occurred suddenly without warning on these two occasions. No engine light came on during either incident.

I've searched the forum for acceleration issues and can't find something quite exactly like my situation - alot of the threads are about problems with manual transmissions or about losing some, but not all acceleration while driving.

The possible causes from my forum reading include:
brake switch flapping cutting engine power
valve adjustment needed and overdue (I can't remember my last valve adjustment)
Loose ignition coils or plugs (I had new ignition coils installed several months ago, but outside the two incidences have not had any problems)
PCM needing replacement, Power train control module replacement
Throttle Position sensor issues
clogged fuel filter or fuel injector problems
Fuel pump or vacuum leaks

Anyone experience the same behavior described and found the cause for it?

 

Tuned in to hear any findings.

In regards to the faults you listed above:

• Throttle Position sensor: I'd expect a code with a fault like that..
• Valve Adjustment: you'd hear the engine being crappy, and it wouldn't just drive better.
• Loose ignition coils: Misfire code
• Clogged fuel filter/injectors: engine would run crappy
• Fuel pump and vacuum leaks: engine would shut off if it was bad enough to stop you
• Brake switch: not familiar with this one, it sounds possible but you seem to be losing connection between the engine and transmission
• PCM: My least favorite diagnosis for people and cars alike. Basically means "I don't know," is commonly the result of someone jumping the gun unless there's legitimate reason to suspect the brain.

Have you checked your trans fluid?
I've definitely seen off fluid levels create this fault in CVT transmissions (usually when trying to suddenly accelerate) and once personally in an automatic where it was much harder to pinpoint. I think the tranny would go to change gears and it.. well, I've never disassembled a trans, but I think there wasn't the right amount of fluid to get into the next gear, or there was too much. Power would just completely drop out like a severe clutch slip.

If your issue isn't transmission fluid, my money's still on the transmission, but I'm not sure what the fault will be. can do some reading.

 

Thanks for the reply. I'll check my trans fluid today and let you know. The brake switch was from this thread: https://www.fitfreak.net/forums/2nd-...oss-power.html

Apparently auto makers started incorporating it after Toyota had problems with sudden acceleration triggering, so applying brakes can cut engine power, but I don't know if my 2009 was before that was an issue or not.

Thank you for narrowing down some of the causes. The last time I had a problem I had the dealer and my mechanic check it out and they just went on a wild goose chase charging me hundreds of dollars to check this and check that. Finally I just asked on this forum what other people found was the cause (it turned out to be needing ignition coil replacements to stop engine stuttering according to folks on this forum) and so I just stopped all the expensive inspections, bought the ignition coils and had them installed and that solved the problem immediately. So I'm hoping to get suggestions from people who experienced this new thing and solved it to skip all the fruitless costly inspections.

 

I believe your car does not have the brake-cut feature (VSS). We determined it in a thread about left foot braking. But that's easy to test, if the car still drives (hit both pedals).

 

Thanks for letting me know. It sounds like it's probably some transmission related issue or possibly TPS if I can get a code indicating that. I'm curious if other people experienced this behavior and found the cause.

 

I understand your apprehension. Transmission fluid may well be all that's needed, but we'll see. The faults I mentioned earlier were resolved with proper filling of the transmission and, in the case of the automatic, changing from OEM fluid to aftermarket. I don't think the latter will be the case here as many run OEM fluid in this car and have no issues.

 

I went to AutoZone and used their code scanner. The code that came back was P0171 System Too Lean (Bank 1). The recommendation is to replace the Mass Air Flow Sensor, but it sounds like that's probably not the issue.

I also checked the transmission fluid and the level is between the marks on the stick, but the fluid looks brown-ish. Maybe it is time for a flush and new fluid since my understanding is the fluid should be light red and transparent.

I had my last fluid change at 147k miles, so with mountain driving and some recommending getting it changed every 30k miles, maybe it's due.

 

Can check for vac/exhaust leaks, check plugs for torque, color and internal failure, adjust valves, clean the MAF, run any kinda normal fuel cleaner to clear injectors in case they have some goop in them (if the car's been sitting or you got iffy gas.) any one of those things could fix a lean o2 sensor reading, but none of them would permit the engine to rev in gear without transferring power to the wheels.
It would be reasonable to assume a maf failure after rendering the above services and/or testing for signal voltage from the maf.. But I believe the code and fault, at least mechanically, don't have anything in common. :/ I mean.. I guess if the engine lost compression? but then like. it would run really bad.. and not go back to normal.

 

I agree with you, it does not sound like the MAF sensor issue is related to what I experienced with losing acceleration and still getting high RPMs. I scheduled an appointment to get a transmission fluid flush and refill since it sounds like that solved the problem in some similar cases you saw. I'm done with the wild goose chase inspections they do and then come up with nothing or highly speculative and probably incorrect diagnoses and repairs. We'll see if flushing the tranny fluid does the trick. Thanks again for your help.

 

You're doing the right potential fixes, you should change fluid, but to the extent I have an opinion ..

You said you verified you were correctly in drive. Smart to do, I'd probably forget. But, I suggest that the automatic trans shift control does not actually move gears, it sends a signal to move them. Is it possible that a faulty shift control sensor, TCM, or solenoid could pull the trans into neutral even though the lever is okay? In layman's terms, driver thinks trans is in drive, trans thinks you want it in neutral. I can't see you being able to rev high without motion while still being in gear ... At least, not without major internal problems that would be regular and not infrequent.

I've never heard of that specific problem, to be honest, but that was my initial reaction when you said you checked the shift lever.

 

Thank you for suggesting this possibility. I'll add it to my notes to ask at the dealership so they can check on it. What you're saying makes sense as another possible cause.

 

Just to update, I got the transmission fluid change and the car feels like it drives better. The mechanic also found that the crank seal was leaking, so I don't know if that was contributing to the problem or not.

I'll post here if I lose acceleration again, otherwise maybe the new fluid did the trick. Thanks again for the suggestions.

 

Glad to hear it. Keep us updated.

 

This sounds a lot like what happened to me when the computer had issues and had to be replaced. Sometimes the engine would lose power when turning and not respond to the throttle for a short time. Fit was six years old at the time but had less than 5 thousand miles on it. Had to go to the dealer who asked Honda to do the fix for free due to my low mileage even though out of warranty. Honda came through and it cost us nothing out of pocket.

 

That would be 100% unrelated to your issue . I think everyone's crank seal is leaking after 120K miles or so ... not big deal unless you are dripping oil .

 

That's what I figured. I'm a little concerned because I've read that a leaking crankshaft seal can lead to ruining the engine if oil gets in there and the recommendation is to get it taken care of.
The only problem is the dealership has had the part on back order for weeks.

I think I'm going to order the parts myself. Does anyone recommend a particular brand or part for the front and rear crankshaft seals on a 2009 Honda Fit?

Just to update on the acceleration issue - ever since changing transmission fluid (full flush) I have had no issues - I think that did the trick.

 

Rockauto's seals with the hearts next to them.. Fel-pro and mahle are both good gasket makers. Although I can remember some repairs on some cars where the fel-pro gasket didn't fit, I don't think you'll have trouble here.

To my knowledge, main seal failure isn't necessarily any bigger a deal than other oil leaks. It keeps oil in the engine rather than out of a specific area. It matters if your engine runs low for long and is big trouble if you run out. I'd be more worried about a quick lube shop cross-threading or not tightening the oil drain plug, which has left a number of people I've known personally with seized engines.

I don't believe there's anything special about the crank/main seal except that it's a bee to replace. I don't know whether it's easier to pull the transmission or the engine. For me, the manual transmission only took me a couple days when my clutch was failing.
a shop would likely charge a lot. I'd blow it off unless the oil loss was significant, but that's just my opinion.

Really stoked your trans issue was resolved. One frustrating note. if you move forward with the main seal issue, you may have to drain and refill the transmission fluid again (though a flush wouldn't be necessary)

 

All good advice above here . If the mechanic says the main (crank) seal is leaking I would "assume" he means its the front , which is easy to access . The rear requires the removal of the transmission .

I have a friends with a 2000 Suburban with a rear main leak , he just puts a quart of oil in it every month or so . Been driving it like that for 3-4 years now.
We have a rebuild engine that we are just going to swap in to fix it , lol .

 

Thanks for the info. It's starting to sound to me like it's not a big deal.

The mechanic just said "crank seal" on the inspection report and didn't specify the front or back seal, so when I called another shop to try to get it ordered and fixed they didn't know what to order and an inspection would be another $100.

It's been weeks and multiple calls to follow up on getting it fixed, but it seems like the dealership does not want to take my money and make the repair so I'm about to give up. Now that it sounds like it's not as big an issue as I thought, I'm thinking I don't worry about it and check my oil level more often.

 

@ANGST

I've talked to a good number of folks for whom the dealer wrote up a rear main seal replacement and a bill for 4 large. It's a low hanging fruit.. If your valve cover leaks, or your oil filter, your oil pan, your pcv valve, or your main seal, they all end up at the bottom of the engine blowing backwards from wind.

I wouldn't tell someone their main seal was leaking if there was any oil residue on the top half of the engine/anywhere other than around said seal and down and back.

EDIT: Good luck with that Suburban. I hope it doesn't give you too much trouble