Perkins engine won't start after cooling system overhaul.

[marcjsmith]

JR i did a fuel filter change on my 4108. is the split filter on the engine, but i also added two racors. got fuel to the racors no problem. I was getting some fuel out of the injectors. but I still had air in the canister on engine filter. took some doing and finally got it going.


if you can block off the intake while someone else tries to start, engine will spin faster then remove the intake block and small squirt of wd40 should help as well.


I also used my oil change pump and sucked diesel fuel through the engine fuel filter. this helped as well getting the offending air bubbles out of the system


i have not had to use the perkins thermo start in forever...

[Jolly Roger]

Success at last!!
I wire brushed the return connections and returns from both banks of house batteries. Yet still, the engine would not start.
I re-bled both nipples on the injection pump, using the hand lift pump, this time my wife nipped up the screws while under pressure. Still no start.
Next, I completely unscrewed the aft injector pipe screw, then cranked the motor until a jet of fuel came out of the nozzle, but still no start.
I did the same for the next injector, no start, but faster cranking.
After bleeding and tightening the third injector screw, the engine fired, and all systems are go!
An absolute torrent of water is also gushing out of the exhaust pipe, more than I have ever seen on any single-engine boat I’ve ever been on. But then so it should be, the whole water system having been completely dismantled and meticulously cleaned, probably for the first time in 45 years.
My greatest thanks to all who responded, and for those who guessed right, congratulations.
I have given this detailed report so that anyone else might benefit.
I have now completed an extensive article about the whole cooling system dismantling and cleaning saga. It will be published in Cruising World later in the year, so I can’t release it here, but if anyone would like to read it privately, PM me with an e-mail address.
JR

[Jolly Roger]

I spoke too soon. I had more frustration with sluggish starting, even after fitting a brand-new battery.
So I took the starter off, (and could have done with a fork truck to lift it out), and removed the end cover. It was very, very dirty around the brushes and commutator, so I sprayed the thing with Purple Power degreaser, then washed it out with a hose—four times. I then dried it with a hairdryer and cleaned the commutator with fine sandpaper. I considered I had nothing to lose, I had my money ready for a new starter.
I stuck it back, wired it up, and bingo! I didn’t even hear the starter whir before the engine fired up. I then stopped and started it five times in an hour, and it fired immediately.
I now think that was the actual reason it wouldn’t turn fast enough--nothing to do with terminals, lead length, battery condition—just years and years of muck in the brushes and commy’.
You live and learn…

[team karst]

I'm going to suppose that with non glow plug diesels, a slow(er) crank means not enough heat is generated for ignition. Too much heat loss in the cold metal stuff...
Measuring cranking speed would be an interesting topic.

[c.K.]

Originally Posted by Jolly Roger

Thanks everyone for these suggestions. I’m going to investigate and try all the ones which are relevant, (the engine doesn’t have glowplugs) and I’ll report back in a few days.
JR

Hi
the engine does not have 4 glow plugs but a lighter in the air intake combined with a bit of diesel
Believe me it is an air lock in your lines after you have vented all and used the primer pump ( make sure it is not on the Cam) then open one of the nuts to the injectors and turn over the the engine by shorting the starter repeat if NEC all four make sure fuel sprays out
Should start after this