This gasoline K25 engine will not accelerate when put into forward or reverse (no visible codes). The truck revs in neutral, or using hydraulic functions in neutral. The oil light is on and sometimes goes out, but oil level is good, but dirty. Truck temp. is mid-range. The operator said, the truck needs to idle for about an hour, then it will accelerate in gear; if shut down, only for a minute, it will not rev in gear again.
Perhaps a bad oil sender is throwing the truck into a "slow mode?" Maybe old oil has thined out, not allowing the sender to read pressure well enough? Perhaps the oil pump is faulty? Could be everything, or has nothing to do w/oil.
Any suggestions?
Showing items 1 - 20 of 25 results.
swoop is right, especially if it is a sealed alt for an lps version truck.
Sounds good swoop, will do
14.6 is an ideal output for those systems
if its under 14 then there may be high resistance in the charging wire off the alternator large terminal that goes to the battery. If its like the mitsu/cats there are a couple of fuselinks that can corrode up and cause high resistance also.
And if/when you replace that alternator? get a NEW one, the remans dont work half the time. 3rd party aftermarket regulators in those remans are junk.
Good thinking snowmonkey, I have every intention of replacing the alt. Yes, it is putting out about 14 volts but will replace it as a matter of course.
Is the alternator possibly weak, if the symptoms are linked to the supplied voltage, the alternator when energized(running) should supply all the voltage/current required to power all the components with enough left over to charge the battery. Alt voltage ideally should be over 14V with a healthy battery.
Found the problem today and you guys would never guess what it was. The truck was alittle slow cranking due to the begins of a bad battery. Decided to change out the battery for alittle easier starting. After the change, the truck returned to 75% power. Now its alittle sluggish, time to look at the transmissin.
Does anyone have the pressure #'s for the ports, and where they are located on the trany. I think there is a torque convertor, forward, and reverse port.
OK everyone, the customer oked the repairs on the machine and we're about to attack the issues. The problem is, this is going to be an on site repair. The flex plate was diconnected from the engine, and the problem is the same. Therefore the issue is not in the trany.
We are going to start by replacing the oil, water, and trans senders/sensors to see what happens. Will keep everyone posted, any other ideas would be apprceiated.
That is a P-47 Thunderbolt aka JUG.
George, when I get the results I'll be sure to advertise them to all
Thank you RCAV8TOR, we'll give it a try, but for now the customer wants to retire the machine temporarly. We will find the issue w/ all the input, and let everyone know the cause when the customer wants the repair. Your photo, is that a '43 Grumman Navy hellcat?
Sounds like you have a trans temp sensor going south or possible tranny overheat. Try unplugging trans temp sensor and see if unit revs in gear. Use a thermo gun to shoot trans lines. These engines will back off engine rpm when tranny is hot.
Did you get this problem sorted?
When you press the acc pedal in gear is there any numbers coming up on the dash?
All fault codes will be displayed on the dash either engine or ecm.
George
have you confirmed the connection and wire from the trans motion sensor (down low under the trans. I think on the right side as the operator sits)?
Do you loose the fuel pressure? That is about the correct pressure for this injector setup fuel rail, but the pressure should remain constant.
On this truck, the trans solenoids are powered through the ECU, and this truck even has a signal to the ecu from the directional control for neutral, not like most older units where neutral was just 'no signal'.
A failure of the ECU to see any signal, or a signal on neutral as well as a direction would produce a p22 error.
I would strongly suspect the oil sender, which if you had the software and cable, you could hook up and see a 'low oil pressure' error signal, that will reset just like it resets when the motor starts up (and if that low oil signal shut _off_ the motor, how would you ever get the motor to start until it had oil pressure pumped up?).
I find it does not matter {much} what language the operator speaks, _I_ am the one that has to be able to talk "forklift" to the machine.
old joke time; do you know the difference between a "professional" mechanic, and a "shade tree" mechanic?
.
.
.
.
wait for it
.
.
the 'professional' knows how to talk to the machine, the 'shade tree' mechanic only knows how to cuss at the machine.
;-)
Ok, now I didn't think to check the dash as the when depressing the pedal, for codes. The engine revs fine in neutral. In gear, idle only. There is no attemp of the engine to gain RPM, bog down, or slip, when in gear.
I disconnected the trany soliniod, put the truck in gear and it reved up fine. The dash was blinking w/ all its lights, but it rev up fine, and put the connection back. I pressed the inch spool, put in gear, idle only.
I arrived early in the morning before initial start up, (difficult to understand non-English speaking people). I found, that the truck moved, and reved when in gear.
After several minutes, idle only when in gear. We let the truck idle while working several hours on another machine, idle only in gear.
We do not get a slow mode, we get idle only in gear. It would seem that it is temp related, and an electric signal issue.
We trying to isolate the problem, and dont want to just replace sensors. But the 4 wires on the trany soliniod have a some type of signal entering and/or leaving to the ECU.
The fuel pressure is about 55 to 58 lbs for about 1 sec w/ the key switch initialized.
How about the air flow sensor ?
usually when the truck goes into slo-mode it will still accelerate but just will not rev up to full rpm's. It should still move though.
if your having to wait an hour before it will move or accelerate enough to move?
sounds to me like a tranny pressure issue
run pressure checks on the control valve and see what pressures you are getting at the pump and clutch packs
pay attention to the inching pedal pressure as well.
check the inching spool and make sure its not enguaged, check the lever the inching cable hooks to and make sure its not sticking.
these things shouldnt cause the 'no acceleration' issue but its one thing to rule out.
as for the oil pressure sender light , get a pressure guage and check oil pressure at the sender, see what pressure your getting. as was said it could just be a bad sender.
and yes a bad signal from the oil pressure sender can make the ecm go into slo-mode or in reality it should shut down the engine in the presence of low or no oil pressure.
just some thoughts to ponder while scratching your head
does this truck have any sort of "dot-lock" installed? this sounds like a dot-lock traction controller out of calibration. you may need the software and cable from dot-lock to be able to calibrate it.
you say this is "straight gas"?
I did not know MCFA made any "straight gas" trucks in this size range after tier 1, although they did make some dual fuel.
Also, as far as I know, all the MCFA gas units after tier1 require high octane gas, or they don't run well.
also, are you SURE that at the time it has no accel function, that it has no code right then, that resets? ?p22?
also, check the wires in the plug to the accelerator pedal position sensor (foot pedal pot)
Well those are the questions, I guess I have to get a service man on it if noone has come across this issue.
I'm not familiar with your unit, but the first thing I'd do would be to address the engine oil light. It could be as simple as a faulty pressure sender, or a symptom of a larger problem ( wiring harness issues, etc).
Do these trucks have some sort of safety that puts the engine in idle mode? If so, what parameters have to be in place for the unit to put it there?
Ok biglittlestar, I'll give it a whirl. It doesn't seem to bog down though, just seems to go into idle.
I reved the engine in neutral, and poped it into gear while reving, and it went right into idle
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