JD 445 Runs Rich but Only under Light Load
JLMiller
Join Date: Aug 2010 Posts: 32 Deerfield or Sanford, wherever the weather's nicer Pics |
2019-06-02 198457
I recently noticed that my 1998 JD 445 runs normally under nearly all conditions (slow, medium, & full throttle idle; full throttle medium load with mower engaged; and full throttle heavy load with mower engaged, traveling, and mowing). Under light load (full throttle, mower disengaged, traveling) it hunts or surges and blows some black smoke.
I checked the fuel pressure and flow rate. Both were well into the normal range. I replaced the fuel and air filters just on principle. Nothing changed.
I've gone through all the tests for the air temp, coolant temp, and MAP sensors. Resistance values are close to spec, and all the sensors respond properly: for the temp sensors, resistance goes down with increased temperature; for the MAP sensor, output voltage is near 5v under ambient conditions and drops with increased vacuum.
I disconnected one sensor at a time, and the injection status indicator light displayed the correct long / short blink sequences for each one. The one thing I did notice is that previously, if I started the engine during the initial 2-second fuel pressurization, I'd get a long-long-short-short blink sequence. Now, even if I start the engine with no initial pause, I don't get that indication.
Please tell me that I'm not looking at a fuel injection control module replacement to the tune of over $1.2K.
Reply to | Quote Reply | Add Photo
JD 445 Runs Rich but Only under Light Load
BigBoyBob
Join Date: Oct 2016 Posts: 21 |
2020-04-15 199082
Did you ever resolve this, excellent post on the topic. $1200 for that module ouch is that like over 25% of the cost of that tractor new? ....
Reply to | Quote Reply | Add Photo
JD 445 Runs Rich but Only under Light Load
JLMiller
Join Date: Aug 2010 Posts: 32 Deerfield or Sanford, wherever the weather's nicer Pics |
2020-04-20 199087
After a couple of weeks of troubleshooting with no indication of specific fault, the problem disappeared, the tractor behaving normally for the rest of the season. If it's not broke, you can't (or shouldn't) fix it. It's put up for winter now; I'll see what happens this spring. ....
Reply to | Quote Reply | Add Photo
JD 445 Runs Rich but Only under Light Load
BigBoyBob
Join Date: Oct 2016 Posts: 21 |
2020-04-20 199090
Anything that goes away on its own is great. Now that it is gone through winter storage I would be sure to use fresh fuel. Best of luck ! ....
Reply to | Quote Reply | Add Photo
Go Top
Share This