John Deere 445 stumbles on cold start

[olgreyhair]

Thanks. I give it a try and report back. So you start it a min throttle and increase it I assume after it warms up a bit? G

 

[beenthere]

Throttle position is not as critical as the time for the fuel pump to charge the fuel system. Waiting until the fuel pump stops which just takes maybe 5 seconds is the more critical of the two. Hope the test will work for you and you let us know how it works out.

 

[olgreyhair]

Just an update. Tonight I went to start the 445. It cranked over a few times, tried to catch , and then just flooded itself out. I had to remove the plugs and dry them out. It then started right up, smoked a bunch to rid itself of the excess fuel and cleaned right out and ran fine. Very fustrating. I hate to do it but I think it needs a MAP sensor. Hard to test it if it works sometimes. Don't know what else would cause a flooding condition and then clean up.

 

[BBO]

Just an update. Tonight I went to start the 445. It cranked over a few times, tried to catch , and then just flooded itself out. I had to remove the plugs and dry them out. It then started right up, smoked a bunch to rid itself of the excess fuel and cleaned right out and ran fine. Very fustrating. I hate to do it but I think it needs a MAP sensor. Hard to test it if it works sometimes. Don't know what else would cause a flooding condition and then clean up.

Have you pulled the fuel pump up to check that short piece of hose?
When everything is working it really does not matter where the throttle is set at.
The EFI should simply start, and start fast.

 

[olgreyhair]

I will check that before ordering a MAP sensor. When I turn the key you can hear the fuel pump run for a few seconds, the light on the dash goes out and it usually starts pretty fast. After it runs for say 15-30 seconds, it loads up, chokes, sputters, and usually clears itself. Runs fine after that. Twice now it has started, ran for just a few seconds, and flooded out. At that point it will not restart until you pull the plugs and blow out the excess fuel in the cylinders. Then it will restart and run fine. What's happening is it's getting too big a dose of fuel at cold start. as soon as it starts to warm up, everthing works as it should. I'm thinking sensor or maybe fuel pressure regulator. Although I don't thing the regulator would go from being good and then bad.

 

[jd3x]

I will check that before ordering a MAP sensor. When I turn the key you can hear the fuel pump run for a few seconds, the light on the dash goes out and it usually starts pretty fast. After it runs for say 15-30 seconds, it loads up, chokes, sputters, and usually clears itself. Runs fine after that. Twice now it has stated ran for just a few seconds and flooded out. At that point it will not restart until you pull the plugs and blow out the excess fuel in the cylinders. Then it will restart and run fine. What's happening is it's getting too big a dose of fuel at cold start. as soon as it starts to warm up, everthing works as it should. I'm thinking sensor or maybe fuel pressure regulator. Although I don't thing the regulator would go from being good and then bad.

I had a similar condition on my 425. It changed when I switched to using premium fuel. The regular grade fuel has ethanol which has less BTU rating and causes moisture condensation in the tank. Give that a try.

Good luck,
Jd3x
(Start with the simple stuff)

 

[BBO]

Don't know what else would cause a flooding condition and then clean up.

If you get into the injector body they sell a throttle body kit. Orings and stuff in case anything is loose...

I took mine all apart and cleaned everything. If you do this you will learn how it works.
The injector has 2 o-rings and the inside is smaller/fat .
IF this beefy o-ring leaks, it could let raw gas into the throttle during that 2-second pressurization.
I ordered & replaced both of those small o-rings on mine.
It can also let gas seep into the throttle after the engine is shut off. (It would be like a leaky injector)
Also I would suggest you replace all of the small hoses & clamps before you start buying expensive sensors.

You can check the resistance in the MAP sensor if you have a good multimeter.

 

[olgreyhair]

Thanks you. I will be getting into that next week. I'll post what I find.

 

[olgreyhair]

This thread should be called Floods on startup. Tractor is getting worse I'm afraid. Did some diagnostics tonight. Air Temp sensor checks out. Coolant temp sensor checks out. The MAP sensor reads ok from the right terminal to the center, a little bit low from center to right terminal and ok from the left terminal to the right terminal. The manual says to check the output voltage with the key on. I don't know how to connect the test leads of my meter to be able to read output voltage while the sensor is connected? Put it all back together and tried to start it. It flooded itself out and backfired thru the throttle body. My ears are still ringing.I dried out the plugs, cranked it a few times to clear the fuel and reinstalled the plugs. It then started right up and ran fine. Very frustrating!! Next to check the fuel pump hose piece in the tank I guess.
Any ideas would be helpfull. Does a fuel pressure regulator ever stick closed and deliver too much pressure? I'm still thinking it's a MAP sensor problem though. Thanks, George

 

[BBO]

Next to check the fuel pump hose piece in the tank I guess.
Any ideas would be helpful. Does a fuel pressure regulator ever stick closed and deliver too much pressure?

My bet is on that hose... The pressure regulator looks like this.

Click to enlarge.

If you want to check several items at once, get a pressure gauge setup between the tank and the throttle body.
It should build up pressure in those 2 seconds and hold it.
The regulator must have some sort of spring inside and you could take it off and clean it good inside.
I cleaned mine and ordered a new o-ring after taking it off. See photo.

Another thing I done was to remove the return hose at the fuel pump and then turn the switch on.
This little fuel pump is tiny; don't expect much fuel to flow back as the regulator releases the pressure.

What you are calling flooding may be fuel not really fanned out from a improper spray from the injector.
And that hose can cause it to happen.