John deere 450 lc 1999 loss of power

[JackS]

I recently purchased this machine that has been sitting a while. It starts right up and idles up and down fine and will run full throttle with no miss or sputtering. Whenever I try to track or lift boom it will bog engine down to the point of stalling engine if I don't let off. Once I let off it immediately runs to full throttle. No lights on instrument panel. I've put new fuel filters on it drained fuel tank and dropped the center piece out and washed tank. Alot of water and and sludge was in the bottom. I've also removed intake air filter tube going to turbo just to make sure it was getting plenty of air. Nothing made any difference it still acts exactly the same as it did when I picked it up. I still need to change hydraulic filters but I'm not convinced that's the issue because there is no pump whining or flow issue that I can tell . The engine does not smoke and sounds perfect at full throttle. It just bogs it down Whenever I use the hydraulics, I did notice however if I boom up and stick in at the same time it did not seem to pull the engine down as hard. It still did but not near as bad so that does have me wondering if its something with hydraulics. Did record the throttle cable linkage whenever i would use it to make sure it wasnt letting of the throttle under load and it doesnt. I also tied the full shut off selonoid in on position to make sure it wasnt causing any issues either still no difference. Where do I go from here? Is there something sticking in injection pump or maybe mechanical lift pump not building enough under load (alot of water in fuel whenever i picked it up)? Or bad boost leak? Or could the hydraulic filters be plugged enough that it restricts so much it pulls the engine down? Any help would be appreciated I'm going to get the rest of the filters changed just thought I'd see if anyone had some ideas in the meanwhile.

 

[mg2361]

How about a complete machine serial number?

Unfortunately, other than confirming engine power with boost check, you would need someone with MPDr to troubleshoot that one.

 

[JackS]

 

[JackS]

This machine is running a mechanical lift pump and injection pump. I've installed a new lift pump and still no difference. Could there be something stuck in injection pump causing it not to add fuel once under load? The turbo looks practically new and still thinking that's not issue because it never smokes like it would if it was starved for air. I'm doubtfull this machine has new enough electronics to diagnose the issue with code reader. It has to be something with fuel or air because it's holding it at full throttle on side of injection pump I'm assuming if there was some type of de-rating it would be pulling the throttle cable back. If it had a major boost leak or turbo issue wouldn't this machine black smoke bad under load? It's like you just idle it all the way down until it almost dies while trying to track or moving boom/stick. It always starts right back and will go straight to full throttle. I thought maybe plunger was stuck in injection pump so I've cracked each line individually while running and it would make big difference on how engine ran. It runs good and sounds good it just has no power. I'm not sure what to try next.

 

[892ELC]

If you feel its still fuel resitriction, have you taken apart the primary fuel filter housing and cleaned it out?

 

[JackS]

No I haven't. I put a new water separator filter on and removed the 2nd filter out of the system and still no change. I thought about removing all filters and hooking directly to lift pump just too see if that was the cause. But removing the block mounted filter out of the system made no difference. Nothing I've done has made any difference at all so far.

 

[mg2361]

That is why the low pressure fuel system pressure should be checked. If you have good pressure to the injection pump when the issue occurs, then that part of the fuel system is good.

Turbo boost checks for proper engine power, not necessarily for a bad turbo. If the turbo turns freely and does not have excessive play or any housing rub, then engine power would be the issue if boost is low. If low, then fuel or air delivery would be the most likely cause. If within spec, then you would have a hydraulic issue. My gut tells me you have a hydraulic issue, but the engine has to be eliminated first.

Have you looked at the PVC (bottom controller) blinking light? Does it blink once a second? Have you jumped the diagnostic connector to get the blink codes?

I'm doubtfull this machine has new enough electronics to diagnose the issue with code reader.

That machine is new enough to look at the electronically controlled hydraulic system with specific diagnostic software, not "scan tools". The engine, however, no electronics, so no to diagnostic software.

 

[JackS]

I have not looked at PVC nor know anything about it. I'm assuming it's the computer behind the seat in the cab?

 

[mg2361]

I'm assuming it's the computer behind the seat in the cab?

Yes, the bottom one is the PVC. Ignore the top one.

 

[JackS]

So what can I tell from that or how do I jump the diagnostic connector?

 

[mg2361]

So what can I tell from that or how do I jump the diagnostic connector?

If the light is on solid, or not lit at all, there is an issue with the system causing the PVC to either shut down or lock up. Jumping the connector will give you codes, if there are any, but only if the light is blinking once a second (PVC is working normally) when performing this test. The codes will be 2 digit numbers, with short pauses between the 2 digits of the code, and a longer pause between codes.

 

[JackS]

I'm currently trying to upload video of it I'm not sure what's going on. The first video I took would not upload and it was blinking codes after I jumped connection. So I took a separate video trying to make the correct file for uploading and whenever I jumped the connector the light just goes out now?

I did try to run it some in between videos I'm not sure if that had anything to do with it.

Also I noticed if I run machine right below half throttle it's slow but never bogs engine down. While I was raising boom I tried increasing to full throttle at the same time and all that did was make it bog down to almost killing engine.

 

[JackS]

Best I could tell from first video I uploaded it is blinking 1 second on 1 second off before jumping connection. After jumping connector It still did the 1 sec on 1 sec off and then it blinked 9 times pretty quickly and then after a pause it blinked 4 more times a little slower. Then lights went off so I waited 10 more seconds with no flashing so I'm assuming the code is "94"

 

[JackS]

 

[JackS]

I bought this manual and have checked some of the solenoids particularly the 2 displacement solenoids on the pump. It said should read around 13 ohms and both are reading around 14.5-15. So I assume those are fine? Checked fuses, checked for codes through multiple times sometimes it'll have a random one and then it just goes away. One big thing I did notice is that whenever I run the machine in "precision" mode it does not pull the engine down nearly as bad if at all. So it is now making me feel like you're right about it being hydraulics maybe something to do with the power boost? I'm not sure, I know nothing about these machines and don't know anyone that does so I'm just trial and error until it's fixed. Anymore suggestions would be greatly appreciated. I wish I could find some one with laptop program to check into the system and see what it's saying.

 

[mg2361]

I sent you something via PM.

If in fact you have a code 9, then that would be related to the Engine Control Sensor, which could give you pulldown issues.

At this point I have nothing left to offer. If the EC sensor checks out, then you will need to get the dealer out or find someone with the diagnostic equipment to properly troubleshoot the issue. Again, engine power issues need to be eliminated, then the hydraulics can only be properly diagnosed with diagnostic software.

 

[JackS]

Ive ordered 2 new pump angle sensors. The front pump (one closest to the engine) did not read anything close to the 850 ohms between pin 1 and 3 it also looked like wires were about to break right where they go into sensor. The back pump looked like the angle sensor had been changed more recently but when I unplugged it the connection was full of oil. It was reading around 750 ohms between 1 and 3 but it read more (875 ohms) between 1 and 2. So according to book that is wrong also.

Found a great video explaining how the pumps work. It showed me how the angle sensors and displacement valves control the pump flow leading me to believe that this is my issue.

Will update if this was the fix. Is there anything I should watch out for when installing new pump angle sensors? I know the book says you really need the computer to calibrate them correctly, but I believe I'll be able to get them very close to where they were before. I'll also have to splice connections to match the harness on my machine because none of the hitachi angle sensors (the ones they sell at deere dealer) have same plug and also mine has a female plug on front pump and male plug on back pump and the dealer just told me to splice the correct plug onto new sensor.

Thanks mg2361 for pushing me in the direction of the hydraulics.

 

[mg2361]

Angle sensors are a common issue with electronically controlled pumps on Hitachi's. I sent you some more reading material.