i have a 2005 honda fit, automatic. everytime i shift from P to D, it stops. i have to step more on the accelerator in order for the engine not to stop. also, when the RPM reaches 4, the engine is roaring as if it is being choked.

 

Not enough info and if there is no CEL on then it could be the fuel filter and just talked to co worker about a similar problem and it was a fuel pump relay switch under the steering wheel.

 

^ Good advice. Your engine is either not getting enough air, fuel, or spark. I'd agree with SB- check the fuel filter and pump, then your air filter, and your spark plugs. I'd be willing to bet that one of these are shot- Mark W.

 

Mileage? Under warranty? Maintenance history? Idle speed in P and D?

 

Given that it's an '05, I kinda doubt it's under warranty
But yeah- more info=better diag Mark W.

 

I say screw the self diagnostics and get a (trusted) mechanic to deal with it.

The OP sounds like they don't particularly trust their mechanic and don't want to be "taken for a ride," but not so experienced with working on the car themselves.

 

He just threw it out there on his first post and logged off right away. Every one should have an opinion to whats wrong but he didn't throw that out or any other info, I wonder what hes trying to accomplish.

 

I agree, but would do these steps in an alternate order. Easiest to check first: 1. Air filter 2. Spark plugs 3. Fuel Filter 4. Fuel Pump.

 

I'd look for an interruption in the engine signal that stops the engine.
As far as roaring at 4000 rpm you may not be familiar with high rpm engines or there is some defect in the intake or exhaust system. And yes it could be related to the engine stopping when a load is placed on the engine when you shift from P to D. Will the engine idle OK with no throttle input in D ? If it won't the idle circuit needs investigating. But its one of those conditions that needs direct inspection, not forum guessing.
good luck.

 

^^ As for doing the air filter first, yes, it's easier than the fuel system, but you'd have to have the intake piping PLUGGED before it'd cause stalling. I've pulled dead (and live) animals, nests, nuts, and all kinds of garbage out of air boxes of cars that were running fine. You'd literally have to block off the air intake to cause it to stall, and then it would barely start at all.


^What? An interruption in the engine signal? What engine signal are you talking about? Spark? Fuel injection? That makes no sense.
And every problem should be solved by consulting a professional, not forum guessing Most folks *ahem* on a forum know damn little about how a car actually works. It's always entertaining as a REAL automotive professional to read some of the "knowledge" people try to pawn off as real on the internet Mark W.

 

[quote
^What? An interruption in the engine signal? What engine signal are you talking about? Spark? Fuel injection? That makes no sense.
And every problem should be solved by consulting a professional, not forum guessing Most folks *ahem* on a forum know damn little about how a car actually works. It's always entertaining as a REAL automotive professional to read some of the "knowledge" people try to pawn off as real on the internet Mark W.[/quote]

Sorry I don't have my Fit manual but there is a signal similar to the one from the ignition switch from the computer selection of gear and as the shift lever passes from one position to the other there could be an interruption, which could cause stalling. However, in considering, one would expect that engine signal resumption would let the engine restart quickly enough as not to be noticeable. Unless its a result of a programming 'latching' cutout such as the one on inverting fuel pumps that avoid fire. Computers do strange things occasionally.
When you restart do you have to actually twist the starter or will it restart on its own if you're rolling fast enough?
PS I'm not a great mechanic but I spent a few years on projects designing production engines so last time I checked the majority were all still running. Your problem needs hands on investigation; trying to solve those difficult 5v electronics problems from a distance is risky and low accuracy at best. As for the roaring, hands on investigation again, but my definition of roaring would be an intake noise.

good luck.

 

The item you're talking about is presumably what is known as the PRNDL "prindle" switch, or maybe the shifter position sensor. If these failed, they would NOT cause the engine to stall. They would lock the shifter in Park, or Neutral, or MAYBE in Drive, but would not cause stalling.

I still continue to agree that they should take it in to a proper shop, as there are dozens of possible causes, and since they haven't been so kind as to post up again, I'm assuming either they got it solved, or aren't coming back. Either way, for the future generations- take it into a shop Mark W.

 

I don't believe that signal is all it does. Its also used in internal computer programming for other purposes.

 

And again, I'm not going off of beliefs. I'm going off of emperical knowledge. Run a web search on the functions of these parts and you'll see that I'm dead on- Mark W.

 

Cars are complicated now so getting any knowledge is a good starting point. I dont even trust my dealer because of past history. They dont like me either, the customer before me had a run down of the car and I just got its done. I did not need to hear the car is OK, put my wife took it as a burn. I have to inspect my truck every day a few times a day so I think I can inspect my car.