I just want to start by saying thanks to all the members of this forum. Until now I have been able to search the threads of this forum to help me with all of my past issues, so Thanks for your help. So the problem... I purchased a non running skidsteer (engine in a box) and have been slowly reassembling this puzzle. I have been struggling with a crank but no start issue. Below are some of the specs/background/troubleshooting so far. Caterpillar 226B MJH05677 Cat 3024C engine Problem statement: Engine will start intermittently but very rough idle and will not respond to throttle. Background: New full rebuild after oil strainer issue (I think). New Oil Pump and revised suction tube and strainer New starter and battery with charger connected Rebuilt injection pump (Bosch style Zexel PF(R))-fuel rack was stuck Rebuilt Injectors and tried new ebay injectors (no difference) New battery and on charger/maintainer Troubleshooting so far: Verified valve lash (.008” intake and exhaust) New Glowplugs: validated 12V and app 1ohm and tested visually glows red after about 5sec Bleed air out of system at filter and injection pump then individual injectors Checked compression (6 rotations) approx. 500#/cylinder Connected to fresh Diesel supply (5-gallon container), new electronic fuel supply pump 5-7 psi, Clear supply and return lines to check for air (no air to pump) Removed front cover to recheck governor springs and freedom of movement (all normal, springs installed) Checked fuel shutoff solenoid (Moves freely in and out)- no change with solenoid removed Checked fuel rack with fuel shutoff removed using borescope (moves full range with manual throttle movement) no change in engine RPM when it does idle replaced and inspected all fuel lines/connections for blockage/debris Removed high pressure fuel lines to check timing, video taken in slow mode, verified firing order and appears to inject at 15-20deg BTDC I have tried addressing all of the common issues (I think) from searching this forum and others for similar issues. I am leaning toward a fuel injection pump (not creating enough pressure) issue since it will not respond at all to change in throttle position. So please tell me I am an idiot and I missed something simple. Thanks for reading
You have checked pretty much everything. Care to shoot a video and post it on youtube and link so we can see it?
https://youtube.com/shorts/HTjuvjd_KW0?feature=share
https://youtube.com/shorts/6fCGXN15_A0?feature=share Without injection lines. Noticed Return line was getting air from hose clamp and return line. Tighten connection and no air bubbles now. Still no change.
cannot see for sure...but i think in first vid you are just playing with manual stop lever throttle could be on side of pump....
That looks like a healthy quantity of fuel getting pumped in slow motion there. But maybe there is a problem with delivery under pressure. Is it making any smoke while attempting to run? Hit up thepumpguysc on here, he may have some insight. I would also lean toward a faulty (rebuilt?) pump.
I was actually thinking the same thing about the pump. Grey smoke not black which suggests a timing issue, right? Has flow at 0 pressure but not much at full pressure maybe. I think those Bosch style pfr pumps are pretty simple though but what still confuses me is it is building enough pressure to pop the injectors or else it would not even idle, albeit very very rough. Friday I removed the pump and dropped it off the fuel injection shop to have it tested again.
Hey Bobatack, thanks for taking your time to watch the videos. Sorry I know it’s hard to see in the video with my big ole meat club hands but if you close I am operating throttle not stop lever.
The same camshaft drives the valve gear as the pump elements. So unless the gear jumped teeth, it will be in time. The timing shim under the pump sets timing, but I doubt that would cause an issue of this magnitude. Maybe a little smoke and low power, but I have timed diesels by the "close enough" method and nobody knew the difference.
Have you checked the lift pump they are a bit trouble some on these
Funny u should mention the rebuilt pump.. I got a call from a customer that rebuilt a small Shibira and couldn’t get it started.. He bought a rebuilt pump from a reputable engine dealer.. He said it acts like it’s not getting enough fuel to start the engine.?? I toldm to send me the pump and I’ll take a look.. I had the pump for a total of 5 minutes and found the problem.. The pumping plungers were so gouged u could catch a finger nail in the scratches.!! NO WAY was this pump gonna start this engine..or any other as a matter of fact.. I put in new plunger and barrels along w new gaskets and orings and a calibration.. sent it back and got a text that the engine started on the 1st revolution... imagine that. But it looks like, from the video, that your pumping plenty of fuel at cranking .. only thing I can suggest is the timing shims under the pump.?? OH, but I couldn’t hear how fast it was turning.. If your not turning fast enough to heat the cylinders, it doesn’t matter how much fuel your dumping into the engine.. it ain’t gonna start.
The timing shims were replaced with new ones from CAT. Made sure they were the same based on measurements and numbers on shims. I would have thought the starter is fast enough because it seems to idle although very sickly. Went ahead and ordered a photo tachometer to check starter speed anyways and will let you know when I get it. Expect to know something about the pump by Tuesday (6/29). Thanks for all of your feedback!
Just b aware that the reflective tape that comes w some of those “less expensive” guns is pizz poor, even tho the surface is degreased. Degrease the hub and place a drop of super glue on the surface..THEN put the tape on the super glued spot, AND WAIT.. I wish someone had told me about that before I pulled my hair out.. I’d get 1 reading before the tape flew off.. lol
Well, I got injection pump back and they said nothing was wrong with it. I have not had time to install but was able to check starter speed without pump installed. At the crankshaft 205rpm. Will install pump tomorrow and see if there are any changes.
I reinstalled pump, no changes to starting condition. Connected edelbrock electric diesel fuel pump and clear hose with gauge. No bubbles and about 8psi at injection pump. So I think I can eliminate that part of the system. I was going to perform spill test next to check injection timing(since it was an engine in a box, what if inj pump is not original and the timing is off?) I assumed it was original and therefore the shims are factory. What do you guys recommend?
You pretty much have to check timing now since you have covered everything else. Also check valve timing while you are at it.
Happy belated 4th of July! Hope everyone had a great holiday. I performed spill test and received unexpected results. approx. 14deg BTDC , expected 19-20deg (based on various manuals) My CAT manual does not have this test procedure (just says replace old shims with new shims) I basically used a Perkins 400 series work shop manual (the only difference is I used an electric fuel source instead of a fuel reservoir. Using electric supply pump @ 7psig Set the #1 cylinder on compression and rotated to CCW 90deg Removed the delivery valve from #1 cylinder Reinstalled delivery valve holder and spring Ensured pump rack was at max Started pump, steady stream Rotated until flow reduced to a drop every 7-10 seconds Removed a .5mm shim and now it is set to 19deg BTDC. I am a little worried about this because every manual I have read states you should only have to adjust timing if Pump/cam/crankshaft have been replaced. Since this was an engine in a box I do not know if this pump was original to this engine. As far as checking valve timing, I removed valve cover and when I was rotating engine over during spill test I checked valve lash again (still .008") and appears to be tracking with piston (removed #1 injector and used borescope to check TDC, just to make sure nothing is really out of whack) Is there some other way to check valve timing? I am very thankful for the responses so far but I am also embarrassed and frustrated that I can't figure this out.
Results sound reasonable and it should have run just fine if it was at 14 deg instead of 19 deg, not big enough to care about right now. Remove injection line set and reinstall backwards with injectors hanging out in space and crank engine over and see how the injection spray looks. Danger of high pressure fluid injection of course. Also inspect prechambers while at it, maybe they are filled with crud if that is even possible? Everything worth a look at this point.
So it’s been a while and hate when people leave it hanging after they figure it out. Haha. I bought all new governor stuff but still did not change anything. I then thought I would remove the factory high and low rpm studs(the ones installed in the block below the injection pump), when I removed these and started it, I now have full throttle response. It seems like a red flag that something set by the factory has to be pretty much be removed to let it run.
This is the one that I removed