My rebuilt Perkins won't start

[Dieseltech]

At the risk of taking all the fun out of the back-and-forth about the pistons, I only replaced the rings and liners.

Thanks for the follow-up about finding TDC.
And I hope Miangus is wrong about the timing gears, but it is still a possibility.

I'll be back when I have some answers.

As copied from my MF A3 152 service book, "Due to the odd number of teeth on the idler gear the complete set of timing marks will align only once every 18 crankshaft revolutions"...

 

[miangus]

If you didn't remove the timing cover or if you did remove the cover but not the gears, they should be ok. If my somewhat ancient, memory serves me correctly the pump is either correct or 180 degrees out.

 

[Dieseltech]

That CAV DPA pump CAN NOT be installed 180 degrees out like Stanadyne/Roosa pumps can. The ONLY way it could happen is if the GEARS are installed wrong.

 

[used red MN]

That CAV DPA pump CAN NOT be installed 180 degrees out like Stanadyne/Roosa pumps can. The ONLY way it could happen is if the GEARS are installed wrong.

Can it be assembled by a novice incorrectly internally so the injection deliveries are out of time?

 

[Dieseltech]

NOPE! The drive shaft has a master spline, and the two drive plate to rotor screws are offset so internally it CAN'T be 180 out, unlike Stanadyne/Roosa pumps can.

 

[dextadriver]

At the risk of taking all the fun out of the back-and-forth about the pistons, I only replaced the rings and liners.

Thanks for the follow-up about finding TDC.
And I hope Miangus is wrong about the timing gears, but it is still a possibility.

I'll be back when I have some answers.

Pistons should have been renewed b

 

[gbsmith]

if you lined up the timing marks on the gear train correctly don't worry about the pump being 180 out it can't happen due to the rotation ratio of the engine to the pump which has a dow pin lining it up to the gear, it will be close time even though it isn't set correctly as the slots only allow it to move so far. when you assembled the pump did you install the cam ring in the right direction of rotation and the snap ring in the correct location??? if so set the flywheel timing mark to 20 degrees BTC remove the pump window cover and see if the square part of the snap ring lines up with the mark with the letter E IRC ,if you can see there not lined up then you can rotate the pump to correct it, if you can't see the mark you have have assembled something wrong. if all lines up air bleed the system again try it again, if it still won't start remove one of the injectors turn it to where it can be connected back to the line with the tip visible turn the engine over and and see if it will spray STAY CLEAR OF THE SPRAY PATTERN as mentioned before. i if doesn't spray then you have something assembled wrong inside the pump.

 

[miangus]

Thanks, DieselTech, see what happens when you depend on my ancient memory. I think at this point I would unhook the return line and see if I was getting fuel to the injectors. If it ran before the rebuild and you didn't take the pump apart it should run now. You didn't say if you had the timing gears off or the cover removed. With the cover off I believe some of the timing gears can just slide off. They can be difficult to get bleed.

 

[Jim Mitchell]

Thanks for the explanation DieselTech.
And just to take some of the mystery out of this little adventure, I took the engine down to the naked block, so any place I could have made a mistake is an opportunity.
I checked the injector pump timing last night and made an adjustment to get the mark and the snap ring lined up. I still need to bleed the system and see what happens.

 

[Jim Mitchell]

Here is the latest.
The injector pump was not timed to the engine so I adjusted it so that the c-clip edge is lined up with the E on the pump, at 20 BTDC.
I also took up the top cover of the injector pump to ensure the stop lever wasn't stuck. Maybe yes, maybe no, but now I think it is correct.
I have bled the fuel system a bunch of times and am certain that I do not have air trapped anywhere.
Now when I crank it I get a bunch of revolutions with no exhaust gas, and then several that let out big puffs of white smoke and it smells like diesel exhaust. I have never had this before, but the engine does not try to start.
The smoke/ no smoke cycle seems to be fairly repeatable, although I haven't tried to count the number of no smokes between smokes, and the smokes are not exactly the same number every time.
Here is my question. Is it possible to assemble the timing gears with all the marks lined up but 180 degrees out of time - the piston in the wrong stroke?
Before I take the front end of the engine apart again, I would like to know that is what I need to do.

 

[Dieseltech]

If ALL the gear marks were aligned, then the gears SHOULD be OK. The marks WILL NOT align again on every other turn of the crank like SOME engines will, but will only align again AFTER 18 turns of the crank. Does the engine have a block heater? If so use it to pre warm the engine will help raise compression heat needed for cold starting. Question, did the head get ALL NEW valve seats installed? OR were the seats and valves just ground and re used as is? If so THAT will KILL the compression heat also. Diesels will run on 275 PSI compression but WILL NOT start well cold when it's that low. On pre chamber diesels I prefer at least 350, 450/475 is even better.

 

[Jim Mitchell]

I just lapped the valves to the seats. But they are the same valve and seat matched pairs. I didn't move the valves around among seats.
Right now it is not very cold in my shop but I did try putting a blowdryer in the intake air stream to heat things up a bit. It didn't seem to change anything.
I am trying to understand the cyclic way it behaves with the smoke, no smoke cycle. I don't understand that.

 

[gbsmith]

did you remove the snap ring in located behind the timing window when you tore the pump down?

 

[used red MN]

did you remove the snap ring in located behind the timing window when you tore the pump down?

He said this in reply 7

I made sure to mark the internal c-clip of the injector pump and put it back where it was.

If that applies to your question?

 

[John Deere D]

I completely tore down and reassembled my A3.182 Perkins engine in my Massey Ferguson 50. Now it won't start, even on ether. It doesn't even try except during that brief period that it takes to consume a shot of either.
Since there are a whole lot of places that could be causing my problem, I was hoping that someone could help me pick apart the troublehsooting to narrow down the likely source of the trouble. And, yes, this is my first rebuild project. The engine was running before I took it apart, even with one broken rocker arm.
I am reasonably certain that the timing gears are on correctly. I had to take them apart once already because I put the cam gear on without keeping track of the position of the D on the gear. That corrected the problem I had with the engine exhausting out the intake.
Is it possible to correctly line up all the timing marks and have the engine be 180 or maybe 120 degrees out of time? I did check the flywheel timing mark before I reassembled the gears.
I took my injector pump apart and put new rebuild kit parts in it.
The lift pump has been replaced, as have the two fuel filters.
I get fuel at the injectors but it doesn't seem to spurt out like I think it should.
I am reasonably certain that the entire fuel system has been bled of any air.
I tested the spray on the injectors and that was ok.

Does this diagram give you any ideas of a possible assembly problem?

 

[used red MN]

Does this diagram give you any ideas of a possible assembly problem?

when you assembled the pump did you install the cam ring in the right direction of rotation and the snap ring in the correct location???

I don’t think the part about the cam ring has been addressed yet. It seems I recall Dieseltech having a discussion about this with another CAV pump do it yourselfer in the past. I haven’t worked on any CAV pumps so I can only cheer from the bleachers.

 

[Jim Mitchell]

I can't look at the cut-away for the injector pump and identify anything that I might have done wrong. I have slept since I took it all apart and reassembled it.
I do remember scratching a mark in the housing to reinstall the snap ring where it was when I took it apart.
It could be that I installed something upside down or backwards but I won't know unless I tear it apart again. I do know that I don't seem to have a problem in the section where the fuel enters the injection pump. It fills both cavities.

 

[Dieseltech]

The snap ring location is the LEAST of your worries, the latest spec sheets on most CAV DPA pumps don't even list the letter/snap ring location like they used to. Only the timing line scribe line tool DEGREES location and outlet is given at the end of the spec sheet.

 

[gbsmith]

just curious as to why they quit using the snap ring to letter timing method, in doing that would there be any need for the flywheel marks either, i know that most all the cav pumps on the small MF's i've dealt with will be correct using the scribe lines on the pump flange and timing gear housing, but there is always one that will be and exception to the rule such as had starting, rough idle etc most of the time the timing needed to be advanced a few degrees even though it was set using the snap ring and letter line and it would clear up the problems, then the flange marks would off just a little. others plug and play. as for this case make sure the system has been air bleed, remove an injector from the engine turn it to a position were the tip is visible and reconnect it to the line, set the throttle to full fuel using the starter spin the engine over and see if it sprays STAY CLEAR OF THE SPRAY !!!!. by doing this it will tell you if the pump is building enough pressure to pop the injector, if it sprays install a compression gage or something similar to block the injector hole,( AGAIN STAY CLEAR OF THE SPRAY PATTERN!!!!) try spinning it again when the compression blows hard against the blockage the injector should spray simultaneously if not fairly close you have a timing issue, i know this isn't a dead accurate way but will help determine if you're way off on the timing ,( USE THIS PROCEDURE AT YOUR OWN RISK !!!! ) . i've done several times in the past and it helped solve the problem, one i can remember was it got conned into correcting timing on a ford industrial engine on a crane that one mechanic pulled the pump without setting the engine timing, he reinstalled it, and for 2 days him and 2 more couldn't get it to start all the while i was avoiding their problem then the man i work for ask me to see if i could get it going being he had borrowed the crane and man's mechanics couldn't get it going, so there i was knowing nothing about the timing that type engine, i called the nearest ford industrial dealer to get the timing , he told me it was 23 degrees btdc and good luck that made me feel good, i had it running in less than an hour and all of a sudden i could walk on water, then the owner of the crane ask me to have a look at a small ford tractor they had rebuilt several years before and couldn't get it started, i reluctantly agreed too and the from info i got it should have run, it wound up being the ring to mark was wrong, rebuilder corrected that still no start so i used the above test and determined it was firing #2 instead of #1 corrected the gear timing and it fired up.

 

[Jim Mitchell]

Thanks for that run-down. I will add it to the things I need to try. It seems that the root cause of my problem is timing, but timing of what remains the open question.