2002 Camry won't start after replacing MAF, P0171
 

I have a 2002 Camry SE, 2.4L with a manual transmission. Check engine light came on and the code was a P0171, "fuel system too lean". At the this point the car would start, but struggled and turned over for 5-6 seconds before starting. Once started everything ran fine and I drove from NY to NC and back without stalls, etc. (although CEL stayed on). After a week or so of the CEL coming one, it got to the point where it wouldn't start at all. I bought some starting fluid and then it started up and ran fine. Have been doing that for a week or so now.

I took it to a mechanic and they said to replace the Mass Airflow Sensor. They wanted to charge what seemed excessive to me (~$300), so I bought one from Autozone and changed it myself. I also did the test where you disconnect the MAF while the car is running and it turned off, so I don't know if that's the problem, but the shop seemed convinced that it was and I bought it anyway. Now the car won't start at all. When I use starting fluid, it starts up, but then promptly putters out and stalls. I'm guessing because it's not getting enough fuel? I also changed the coolant temp sensor and then reset the computer by taking the negative terminal off for 15 minutes (not sure if this is the proper reset procedure).

Not sure what to do next. It had rebuilt injectors put in not too long ago, but I guess the injectors could be clogged? Although it seems weird that it would drive for 1000+ miles without a problem if the fuel pump or injectors were bad. I also thought maybe the 02 sensor? Any thoughts/ideas would be appreciated. Thanks.

-Steve

Did you change the MAF? Do you still have the old one?

Below is a list of possible issues for P0171.

Air induction and exhaust system leaks
Injector blockage (you changed these)
Low fuel pressure
MAF (changed)
Bank 1 Sensor 1 open/short in A/F sensor, sensor heater, A/F sensor heater and EFI relay circuits
EFI relay
PCV valve/hose/connections
ECM

Joey,

Thanks for your reply. Yes, I changed the MAF and yes, I still have the old one. As soon as I put the new MAF sensor in, the car would start (with starting fluid. at this point it wouldn't start at all on it's own), but quickly stall. I immediately put the original MAF sensor back in and the condition was the same. For some reason, putting the new sensor in, seemed to change everything. I know that a "crank, no start" condition points to a fuel or spark problem, but do you have any idea why changing the MAF sensor would precipitate this happening?

I also changed the spark plugs (not to fix this problem, but because it was time anyway) as well as the MAF and coolant temp sensor. Now the car won't start at all with or without starting fluid. Thanks again for your help.

-Steve

Also, do you know of any good links to how to test the fuel pressure on this model Camry? It doesn't seem that Toyota did not include the convenient, Schraeder valve? Is there a bolt I can loosen to see if it squirts fuel, etc.? Also, I can't seem to find a good, visual resource that points out where the fuel relay inside the vehicle is located. There's an article on this site that says something like, "there's a second fuel relay behind the glove box...," but doesn't point out exactly where it is. Thanks again.

See link:

https://www.scribd.com/doc/8036644/T...Manual-11-Fuel

Could be failing fuel pump or fuel pump relay. Try applying power directly to the pump.