hard starting enigne?

it may be a weak fuel pump drive until this happens. then check fuel pressure with a gauge you may need an adapter auto parts rent it see link.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

this guide can help as well

https://www.2carpros.com/articles/engine-cranks-excessively-before-starting


Please run down this guide and report back.

The mass airflow sensor and fuel pump and filter has already been changed. still have the problem. i need help on this.

do what I suggested in reply and scan for codes.

A scan has been done the error code is P0420?(faulty catalytic converter) can that cause the problem?

It may but I think you oughtto do what I said in first reply I think your pump is failing when hot

Hello the fuel pump and filter has been replaced still have the same problem
The air flow sensor waa also replaced
Need help on this

from what I getout of your replies you are not scanning for codes only doing the shotgun approach by replacing parts. Other than the one time you did scan it. what is fuel pressure? did you check for vacuum leaks? was the code the correct number?

I just scanned it again the check engine light is on the code is P0420 catalytic converter can that cause the problem

it cold if it were plugged enough what is fuel pressure when this happens.

The car still has the same problem what can be done can the catalytic converter be the problem thats the only code that d car has p0420

I already replied to this have you done anything other that I have suggested? I said it could cause the problem if it were plugged enough. if you are getting the code it should be replaced.

Hello you were very correct a wrong pump was put in the corolla its works very good now
Thank you

Nice work, we are here to help, please use 2CarPros anytime.

Cheers, Ken

Car is hard to start. Cranks fine almost like it is cranking too fast at times. When it starts it runs rough. When going it is all good. Had engine light. Code was for o2 sensor bank 1. Changed it. When I first started it, it did the same thing, but after a few minutes of running it leveled out. After sitting a few she was hard to start again. 210,000 miles I wish it was only 210. Thank you guys!

Hi and thanks for using 2CarPros.com.

A hard start can be the result of a few things. The first thing I would like for you to do is read through this link. It discusses hard starting, common causes, and how to repair.

https://www.2carpros.com/articles/engine-cranks-excessively-before-starting

Now with that in mind, I have a concern. You said when cranking to start, sometimes it seems like it turns too fast. If that is the case, it could be the result of low engine compression (which will cause a hard start) or engine timing which can do the same. What I would like for you to try is checking engine compression. Here is a link which discusses doing the process:

https://www.2carpros.com/articles/how-to-test-engine-compression

Here are the directions specific to your vehicle from Alldata. Picture 1 correlates with these directions. You will need a compression gauge, but most parts stores will lend you one.

_________________________________________


INSPECT COMPRESSION
Warm up and stop engine.
Remove ignition coil.
Remove spark plugs.
Inspect cylinder compression pressure.
SST 09992-00500
Insert a compression gauge into the spark plug hole.
Fully open the throttle.
While cranking the engine, measure the compression pressure.
Compression pressure: 1,300 kPa (13.3 kgf/cm2, 189 psi)
Minimum pressure: 1,000 kPa (10.2 kgf/cm2, 145 psi)
Difference between each cylinder: 100 kPa (1.0 kgf/cm2, 15 psi)
NOTICE:
- Always use a fully charged battery to obtain engine speed of 250 rpm or more.
- Check other cylinder's compression pressure in the same way.
- This measurement must be done in as short a time as possible.
If the cylinder compression in one more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hole and repeat steps (1) through (3) for cylinders with low compression.
HINT:
- If adding oil helps the compression, it is likely that the piston rings and/or cylinder bore are worn or damaged.
- If pressure stays low, a valve may be sticking or seating is improper, or there may be leakage from the gasket.

___________________________________________________________

Lets start with that. Let me know what you find or if you need help with anything. I hope you find this information helpful.

Take care,
Joe

I have a 06 Corolla S and recently i noticed it's taking longer to start than before. It's taking about 3 to 4 cranks before the engine kicks over and starts. Also right before it starts it sounds like its going to give up, but then it starts and runs fine. I changed the plugs and air filter, and added a fuel system cleaner but the problem is still there. The auto parts store said it might be a dirty fuel filter (never changed by the way) but I cant find it.

Usually on the driver's side frame rail. Follow the fuel line from the tank to the engine. One should go to the charcoal canister, the other to the fuel filter and then the pressure regulator.