John Deere 445 stumbles on cold start

[olgreyhair]

Hello eveyone. I recently picked up a 1995 445 with 1100 hrs on the clock. Seems to run well. Has had the cam gear upgrade. I did a full 200hr type service. What I don't knwo is why at a full cold start with 1/2 throttle or so, she will fire right up and then stumble and cough for 4-5 seconds like it's flooding. It then cleans up and runs very well for the rest of the day. Once it did flood it self out. After cleaning the plugs it was fine. I don't know. Is this a function of a faulty sensor or just a trait of these fuel injected tractors? Any advice would be appreciated. It only occurs at cold start. Thanks, George

 

[beenthere]

Have you tried a different throttle setting for warm-up time?

 

[olgreyhair]

It seems that if I move the throttle slightly after startup it clears up. What do you suggest?

 

[BBO]

What I don't know is why at a full cold start with 1/2 throttle or so, she will fire right up and then stumble and cough for 4-5 seconds like it's flooding. It then cleans up and runs very well for the rest of the day.

Are you turning the switch on and letting the light go out before cranking it?

 

[beenthere]

Are you turning the switch on and letting the light go out before cranking it?

That could cause the stumbling problem, if starting too soon.

Also, if run out of fuel or the fuel filter was replaced, may need to bleed the fuel pressure by opening the "fuel pressure relief screw". Just a thought.

 

[olgreyhair]

It seems more like a momentary flooding problem really. Thinking worn injector or sluggish MAP sensor. I had a motorcycle once with a bad coolant temp sensor. It thought it was cold all the time and would flood itself out.

 

[wolfe1]

Neighbor just picked up a old 445 - had the same issue. I watched him go through his start up procedure and he was cranking it right away and had throttle set at 1/2 - 3/4. Brought throttle all the way down and and made him wait a two count after fuel pump quite whining - solved his prob.

 

[beenthere]

The OP has not said if he waits for the pump to stop before starting engine.

 

[olgreyhair]

Neighbor just picked up a old 445 - had the same issue. I watched him go through his start up procedure and he was cranking it right away and had throttle set at 1/2 - 3/4. Brought throttle all the way down and and made him wait a two count after fuel pump quite whining - solved his prob.

Not sure if I understand. Are you saying that he cranked it over after waiting a 2count after the injection light on the dashgoes off and has the throttle set at or a bit above idle? please let me know. Thanks, George

 

[wolfe1]

George - When you first turn the key you should be able to hear a slight whine of the fuel pump building pressure. When that sound stops he waits about 2 seconds and then attempts to crank it. The throttle is all the way down at its lowest setting. Fires right up and runs smooth. We went through this about a month or so ago and these are all the details I remember - if you need anymore info let me know. I do the same thing on my X485 which is essentially the same tractor. I run sea foam through my intake every 200 hours or so and it makes a nice difference - I have over 700 hours now and I swear it gets smoother with age.

 

[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.