Perkins no start overnight, no leaks!

[Doldrumdayz]

Hello All!
I know this has been discussed in previous forums and threads but after reading almost all of them and performing tests i am still banging my head and cutting my knuckles trying to find this air leak!!

From the start:
Perkins 4.108 engine ran fine before, then starting got more elongated.
Finally never started. Found major fuel leak at injection pump.
Had it rebuilt, reinstalled.
Broke off the anti stall assembly bleed screw, ordered new one. Installed. Bled engine (NOT from anti stall assembly again) ran for an hour. SO HAPPY!!!

Next day no start.
Bleeding engine for 5 days now again and again (bled, than ran for an hour) after redoing almost EVERYTHING.

ENGINE WILL RUN AGAIN AFTER BLEEDING AND RUN GREAT.

Tank has been cleaned, its full of fresh off road diesel.
All hoses have been replaced, sealed and hose clamped accordingly. Both filters new.

Tank>primer bulb>racor(new filter)> 12v elec bleeding assist pump> lift pump (new) > secondary filter(new)

I have carefully inspected all my new low pressure fuel lines to the engine and replaced olives, crush washers, etc. Sealed all threads with fuel resistant sealant.

Id really like to mityvac test the system but that would be my last resort before throwing in the towel.

How can it be this difficult?!
Is there a way to test high pressure side for drawing in air after shut down?
Should I install a valve in the return line? Im past the point of being upset about it and now its depression!




Today i got some clear hose to try and direct connect to the lift pump from jerry can and do another overnighter test to see if its a low end problem. I cant see any leaks ANYWHERE!

I love this forum and have read it for years, but now heres my post.

All you smart kind people out there have taught me a lot!
Please help! Im about as blue as the engine now....

[rbk]

Sounds like a leak. Double check both your filters to make sure they are seated properly if you haven’t already. Sometimes those large round rubber gaskets like to twist and leak. Also make sure you haven’t installed 2 gaskets in the engine filter as it will never seal. Then throw on the clear hose and try to see where air is getting in.

[Doldrumdayz]

Rbk thabks for that quick reply.

The gasket kit that came with the napa engine filter 3166 included 3 large o rings, a smaller one and a tiny one.
I used the smallest for the top bolt that sandwiches the assembly, the smaller one for inside the tube upper portion and then 2 of the large ones for around the top and bottom edge of the filter..
This was how I had it before all this started and it ran fine,, but you are saying i should only have 1 large o ring gasket for the filter? Im open to change whatever it takes!

Should my clear hoses go on either side of my racor? When pumping the priming bulb, after it gets stiff, i hear what sounds like air squirts inside the racor.... but no major visible external leaking.

Side note im trying to go direct from jerry can with my clear hoses but it doesnt seem that lift pump can move much fuel if theres air in the line and so i cant work the air out! Jug is higher than engine.

[rbk]

Originally Posted by Doldrumdayz

Rbk thabks for that quick reply.

The gasket kit that came with the napa engine filter 3166 included 3 large o rings, a smaller one and a tiny one.
I used the smallest for the top bolt that sandwiches the assembly, the smaller one for inside the tube upper portion and then 2 of the large ones for around the top and bottom edge of the filter..
This was how I had it before all this started and it ran fine,, but you are saying i should only have 1 large o ring gasket for the filter? Im open to change whatever it takes!

Should my clear hoses go on either side of my racor? When pumping the priming bulb, after it gets stiff, i hear what sounds like air squirts inside the racor.... but no major visible external leaking.

Side note im trying to go direct from jerry can with my clear hoses but it doesnt seem that lift pump can move much fuel if theres air in the line and so i cant work the air out! Jug is higher than engine.

It’s been almost a year since I’ve been able to get to my boat but going off memory there are only 3 selling rings on the oem filter. Make sure the old top one didn’t get left in the housing, this is common and with two in there it won’t seal. Also double check the racor top is properly secured and the inner small O ring is replaced. I’ve had them appear to seat but not perfectly and can cause a leak. After that double check all your lines but also crank on the low pressure lines. Also if you’ve had your injectors out recently did you replace all the aluminum washers on the return rail? Just rattling off the easy stuff for now. Double check all your hp fittings and do bleed the anti stall, just don’t shear or off again (I’ve done the same). It takes a while for fuel to come out three but it will. I find if you get it running and crack the anti stall and have someone increase and decrease the rpm it pushes air out the top faster.

[Doldrumdayz]

Im sorry its been so long for ya, I spent over a year away as well and she wasnt happy about it. Haha

Originally Posted by rbk

Make sure the old top one didn’t get left in the housing, this is common and with two in there it won’t seal. Also double check the racor top is properly secured and the inner small O ring is replaced. I’ve had them appear to seat but not perfectly and can cause a leak. After that double check all your lines but also crank on the low pressure lines. Also if you’ve had your injectors out recently did you replace all the aluminum washers on the return rail? Just rattling off the easy stuff for now. Double check all your hp fittings and do bleed the anti stall, just don’t shear or off again (I’ve done the same). It takes a while for fuel to come out three but it will. I find if you get it running and crack the anti stall and have someone increase and decrease the rpm it pushes air out the top faster.

Really good advice, thanks a ton!

I did remove the entire secondary filter case and inspected.. All gaskets were replaced and none were doubled up. So ill cross that off.
But as I was inspecting my racor, i noticed my hose barb fittings on it werent tight at all. I keep cans of paint in the locker with all this and what ive noticed is the cans like to wiggle and settle close to all the fuel connections and the racor. They could have easily unset the 90° to the racor ever so gradually. (I think i remember having trouble with that fitting when originally installed)
Ill remove and reset those guys.. it could have been that simple.

Injectors were out a few years ago but i did not replace the fuel return washers. Ill do that too.

Ok! Ill (delicately) mess with the anti stall a bit as well.

Today im going to recheck everything like you said again. I know im overlooking something.

Re-reading nigel calders book he mentions about looking through the racor bowl for bubbles when running, and also about the return line to tank back siphoning.

Im gonna believe it was my 90 barb on my racor gradually unscrewing over the years until finally it lets enough air in to cause a big bubble upon settling. Will keep updated! Thanks!

[rbk]

Ya I’d start from the tank and re-check and retighten every fitting just to make sure. Sounds like you may have it narrowed down at least. Good luck

[Capt Clark]

Hang in there, I think you’re close. You are on the right track with the Jerry can use. It’s always good to try and narrow down where the issue is. The fact you see no leaks may be an indication that the problem could be upstream of the fuel pump.

[Telemark43]

Originally Posted by Doldrumdayz

Im sorry its been so long for ya, I spent over a year away as well and she wasnt happy about it. Haha



Really good advice, thanks a ton!

I did remove the entire secondary filter case and inspected.. All gaskets were replaced and none were doubled up. So ill cross that off.
But as I was inspecting my racor, i noticed my hose barb fittings on it werent tight at all. I keep cans of paint in the locker with all this and what ive noticed is the cans like to wiggle and settle close to all the fuel connections and the racor. They could have easily unset the 90° to the racor ever so gradually. (I think i remember having trouble with that fitting when originally installed)
Ill remove and reset those guys.. it could have been that simple.

Injectors were out a few years ago but i did not replace the fuel return washers. Ill do that too.

Ok! Ill (delicately) mess with the anti stall a bit as well.

Today im going to recheck everything like you said again. I know im overlooking something.

Re-reading nigel calders book he mentions about looking through the racor bowl for bubbles when running, and also about the return line to tank back siphoning.

Im gonna believe it was my 90 barb on my racor gradually unscrewing over the years until finally it lets enough air in to cause a big bubble upon settling. Will keep updated! Thanks!

"Re-reading nigel calders book he mentions about looking through the racor bowl for bubbles when running, and also about the return line to tank back siphoning."


excellent advice...watch for even small bubbles

[parado]

I had the same problem, had a diesel mechanic look at it too, no go. So I took my compressor to the boat, plugged the vent line and installed a bung with air hose fitting on the fuel fill port. It was a leak/ pinhole in the middle of a ss braided return line. Do not pressurize more than 2-3 psi or you could damage your fuel tank. This will track it down.

[peter loveridge]

I had the same setup and the same thing. The loop tank-bulb was above the fuel tank. Lowered the bulb below the tank and then all was well, and will start first thing after three months idleness. Figured a tiny leak on when fuel line being sucked bu the fuel pump, but I neve found it

[skipgundlach]

From my phone, so I apologize for any transcription errors!

I installed a fuel polisher system and as a result never changed a raycor other than just to do so.

When I thought I needed to change a racor it turned out indeed to only be a loose fitting in my case at the manual pump on the engine.

Tightened that up and never had a failure after that.

So your fitting at the racor is definitely suspect.

good luck in having that be the solution :-)

[Scorpius]

Originally Posted by Doldrumdayz

Im sorry its been so long for ya, I spent over a year away as well and she wasnt happy about it. Haha



Really good advice, thanks a ton!

I did remove the entire secondary filter case and inspected.. All gaskets were replaced and none were doubled up. So ill cross that off.
But as I was inspecting my racor, i noticed my hose barb fittings on it werent tight at all. I keep cans of paint in the locker with all this and what ive noticed is the cans like to wiggle and settle close to all the fuel connections and the racor. They could have easily unset the 90° to the racor ever so gradually. (I think i remember having trouble with that fitting when originally installed)
Ill remove and reset those guys.. it could have been that simple.

Injectors were out a few years ago but i did not replace the fuel return washers. Ill do that too.

Ok! Ill (delicately) mess with the anti stall a bit as well.

Today im going to recheck everything like you said again. I know im overlooking something.

Re-reading nigel calders book he mentions about looking through the racor bowl for bubbles when running, and also about the return line to tank back siphoning.

Im gonna believe it was my 90 barb on my racor gradually unscrewing over the years until finally it lets enough air in to cause a big bubble upon settling. Will keep updated! Thanks!

I wouldn't do several things at once. You might solve one problem and create another! It sounds like the most likely is air coming in at the Racor fittings. Tighten them up and try again. I wouldn't fiddle with the aluminum washers, bleed screws, etc. at the same time. Just do one thing at a time, and try it, before moving on.

Just my humble opinion. Good luck!

[Movinon1]

I have eliminated low pressure side by running fuel hose from tank to low pressure pump, with clear tube just before LP pump. Bypassing filters and whatever else is between tank and LP pump. I could use gravity to bleed new line into a container. Sounds like you know about the 3 points to bleed engine.

[Gavino]

Have had the same troubles....with our Perk.. if we left it for a day or so....then it was nearly impossible to start without doing a full bleed through again.... the trouble turned out to be the lift pump.....losing pressure and the fuel was draining back...... if we before trying to start the motor...pumped the lever on the lift pump about 10 -12 times until you could feel that you couldn´t pump it up any more....the motor after the usual pre heat and putting on the half a throttle position...it would start within 2 seconds..... there was never any visible leaks, and we tried this out over quite a few times....give a pump and it would start...leave it...and it would need a new bleeding again... good luck with your fixing....

[Doldrumdayz]

Yesterday i rerouted the hoses and replaced the racor with a different one,, bled the entire system again. Its quite messy and im running out of rags. Finally started.

Still no start again rhis morning. There is a tiny tiny air bubble in the newly installed racor on the underside of the centrifuge stuck there.
But engine ran fine for an hour last night with no hiccups while that was in there.

This is quite depressing, i sure do miss my one cylinder yanmar.

A couple thoughts,, since it always happens overnight, and its a no start in the morning, would it be likely that the air trapped or coming in is close to the IP? Or can a tiny stuck air bubble in the line anywhere cause this? Say right at my tank petcock? (The shut off valve on my tank lets fuel drip slowly when its in the off position..) could this be a culprit?

Scorpius yes you're right I should not try many things at once.

Im going to do simple tests for now.
The damn things just such a pain to bleed over and over again.

Its a new lift pump and every connection near there has been removed, olive replaced, and sealed with thread sealant.

I havent checked my hard lines from 2nd filter to IP because theyre in a crammed spot. But i see no visible leaking at them.

Gavino i replaced the lift pump, so i dont think thats it,,


Ill route a clear hose from my return line on top of the filter housing to my tank directly today and try to rebleed and watch for air.. this has got to indicate some air, right? Because its the last route from the engine low pressure side?

Skipgundlach good to hear from you! Dont know if you recall, but you gave me and my friend a case of beer while we were anchored in the Abacos.. 28' morgan named Bare Bones. I always love telling folks about ypur bathtub filled with cases of beer..provisions..