Great War truck Posted April 13, 2013 Share Posted April 13, 2013 We had some nice weather last weekend so i thought i would take the Jeep out for a spin. Battery totally dead and even after charging it there was still not enough juice to turn the engine over. So I bought a new battery. However, the next sunny day the jeep still refuses to start. It turns over nicely and I get a spark ok, so the problem must be the fuel. Took off the pipes going into and out of the fuel pump and blew through them (all fine). However, when i took them off only a trickle of petrol came out of them. It was suggested that I took the top off the carb and put my hand over it to force the carb to suck the petrol up into it. This worked a treat and the engine then burst into life only to stop 5 seconds later as i presume that all of the petrol it had sucked up had gone. The problem must therfore be the fuel pump. This must be a later one as it has a glass bowl and so i can see the petrol in it, but i cant see that it is sucking in new petrol. It does not have a priming lever however. is it worth taking it apart and cleaning it or should i just buy a replacement? if i do take it apart is there anything i need to know. Replacing it looks to be an awkward job and i am not looking forwards to it. Any thoughts please? Thanks Tim Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted April 13, 2013 Share Posted April 13, 2013 Probably fuel pump, hoses, or filter. Remember to check the sump oil level and smell, just in case a perforated diaphragm has been allowing fuel in the sump. Quote Link to comment Share on other sites More sharing options...
arcot1751 Posted April 13, 2013 Share Posted April 13, 2013 I once had a similar problem with my jeep again after standing, I tried all sorts but no change. I then decided to check the fuel filter bowl and the seal was breaking up it didn't leak fuel OUT but it was allowing air IN thus stopping the pump pulling the fuel through, a new seal sorted it and have had no problems since. Good Luck Quote Link to comment Share on other sites More sharing options...
Great War truck Posted April 13, 2013 Author Share Posted April 13, 2013 OK. it makes sense to start with the easiest one first so i will take a look at the fuel filter. I thought, and i may be totally wrong on this but as i can see that the bowl on the fuel pump is full would a leaky fuel filter seal prevent the fuel from rising from the pump bowl? Thanks Tim Quote Link to comment Share on other sites More sharing options...
arcot1751 Posted April 13, 2013 Share Posted April 13, 2013 Yes it would because if there is an air leak it will draw air rather than fuel so you can see fuel in the bowl but it won't move up to the carb, it's much the same as a diesel engine that needs to be "bled" before it will run if air has entered the system. Your problem may not be this but I would certainly try it. Quote Link to comment Share on other sites More sharing options...
deadline Posted April 15, 2013 Share Posted April 15, 2013 Since you have a glass PULSATOR (that's what its called, the air trapped in the top of the dome actually contributes as much as 50% of the fuel flow to the carb) when the motor is cranking you should see the fuel 'jump about'. If its mostly just sitting there then your valves are not opening (most likely the suction side). If you can visibly see fuel in the pulsator then the diaphragm is most likely good (on a metal pulsator you could not see the fuel, and would have to drain the oil). One more likely situation: Take the petrol tank cap off and try to start. The cap is supposed to have a vacuum and pressure release valves (like a radiator cap). If your cap is not venting properly, the tank itself may have slight vacuum and the fuel pump many not be able to overcome it. There are two seals you need to check : One under the pulsator dome, one at the fuel filter. Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted April 15, 2013 Share Posted April 15, 2013 Check all pipe connections are tight as well. Also the short hose, chassis to engine, coud be perished / cracked. Quote Link to comment Share on other sites More sharing options...
Great War truck Posted April 16, 2013 Author Share Posted April 16, 2013 Ok thanks guys. I am getting there. It is not the fuel tank cap as I cant imagine that ever creating a vaccum again. I have blown through all of the fuel pipes and cleaned the petrol filter. Still no good. Next step is to take the fuel pump to pieces and have a look in there. I will see if i can get a rebuild kit from Dallas autoparts and then set to it. I will let you know how i get on. Thanks for all the good advice so far. Tim Quote Link to comment Share on other sites More sharing options...
Willyslancs Posted April 16, 2013 Share Posted April 16, 2013 fingers crossed mate ...................... Quote Link to comment Share on other sites More sharing options...
arcot1751 Posted April 17, 2013 Share Posted April 17, 2013 Good luck, if you can't get a rebuild kit I don't believe the pumps are that expensive complete, at least if you go that route you are totally eliminating one part. :-) Quote Link to comment Share on other sites More sharing options...
deadline Posted April 17, 2013 Share Posted April 17, 2013 The valves in the pump could be stuck shut. Have you cleaned the mesh fuel strainer in the pump? That can get crusty. Take the pump off and actuate the pump lever by hand... you should hear the air move through the valves... it makes a snorting sound if all is working. There is an AC fuel pump rebuild TM TM9-1828A http://www.tm9-801.com/tm9-1828a/index.php If anything is wrong with the pump that TM will show you how to fix and rebuild it. A kit is less than $20 and takes about 30 minutes. Quote Link to comment Share on other sites More sharing options...
Great War truck Posted April 27, 2013 Author Share Posted April 27, 2013 Well i have changed the pump for a new one. I was told that the job was "a bit of a fiddle" by someone who knows and "a two minute job" by someone who doesnt. Anyway, it was a bit of a fiddle but done now. The problem is still the same. No fuel seems to be getting to the carb. I have got a spare carb to try but as no fuel is getting to the old carb i dont think that will make much of a difference. When i pump the lever on the fuel pump i can hear air going in to the carb, but no fuel. Next step is to replace the pipes going from the filter to the pump unless anyone else has any good ideas? Thanks Tim Quote Link to comment Share on other sites More sharing options...
arcot1751 Posted April 27, 2013 Share Posted April 27, 2013 Just a thought, and you have probably already checked but are you sure there is no blockage in/from the tank to the pump ? I ask because a friend had a classic car with a similar problem and it turned out the tank had had a sealant added to combat a leak and this new unleaded petrol was degrading it which eventually totally clogged the pipe from tank to pump. :undecided: Quote Link to comment Share on other sites More sharing options...
Great War truck Posted April 27, 2013 Author Share Posted April 27, 2013 Good thought. I had checked the tank and it is not that. I have however now found the problem. i painted the connections with water and washing up liquid, blew through the pipe and found the leak. I now need some replacement parts so i will be giving Mr Rivers a call on Monday. We are getting there. just slowly. Oh yes, i need it for next weekend for an area event/ fly in. The things we do for fun. Tim Quote Link to comment Share on other sites More sharing options...
arcot1751 Posted April 28, 2013 Share Posted April 28, 2013 Glad you're sorted mate, it will all be worth it in the end Quote Link to comment Share on other sites More sharing options...
Great War truck Posted May 2, 2013 Author Share Posted May 2, 2013 Gosh, when will this saga ever end? There is no fuel going into or coming out of (unsuprisingly) the new fuel pump. All the joints are sound. As i have blown through every pipe back into the tank i wonder whether as the whole system is dry all i am sucking is air. So, do i need to prime the system somehow? I have tried it on the starter but no joy. I am wondering whether a tow start might give the pump enough oomph to suck all the air through and get to the petrol. Any thoughts anybody? How did they start new Jeeps out of the factory? Thanks Quote Link to comment Share on other sites More sharing options...
Pete Ashby Posted May 2, 2013 Share Posted May 2, 2013 Some questions and some things to check: I'm assuming you'r replacement pump doesn't have a manual priming lever ? Have you checked the seal on your bulk head filter Have you cleaned the filter out (they can get very gummy if left with modern petrol in them) Are you sure that your float needle isn't jammed shut in the seat Did you check that the pump sucked and blew before you fitted it Have you checked the flexi hose below the generator it can perish so all you'll do is suck air Pete Quote Link to comment Share on other sites More sharing options...
commander Posted May 2, 2013 Share Posted May 2, 2013 First crack the nut off on the pipe that goes into the carb one turn should be enough then prime the pump and see if fuel comes out, if not next check the flexi connector to check this take the pipe out of the filter put your finger over the end then prime the pump you should get a suction on your finger if not you have a leak on the system if it has got suction reconnect the take the other pipe off the filter and prime again see if you heve suction if not the gasket on the filter is cream crackered Commander Quote Link to comment Share on other sites More sharing options...
deadline Posted May 3, 2013 Share Posted May 3, 2013 Tow starting is not going to do anything useful. You will need to check the hard lines and hoses for cracks/leaks. If you have an air compressor you could pressurize the fuel tank a few PSI and look for leaks, or do the old soapy water test. Most common problem for me is the fuel strainer gasket... if you let the bowl rotate you can damage the gasket quite easily. Quote Link to comment Share on other sites More sharing options...
Great War truck Posted May 3, 2013 Author Share Posted May 3, 2013 Some good news at last. Just been out for a drive in the Jeep. I was happy that we had checked and cleaned everything and it was all now in order, just no petrol getting to the pump. We squirted lots of petrol down the pipe from the filter to the pump until the pump could squirt it out. Then reconnected the pipe up to the carb and the one to the filter. Pumped petrol up in to the carb and then it started just like that. We think the problem must have been an air lock and getting the engine running (even just for a moment) gave the pump enough suction to clear the airlock. Thanks for all the advice everyone. Tim Quote Link to comment Share on other sites More sharing options...
Willyslancs Posted May 3, 2013 Share Posted May 3, 2013 that's great mate , hope that's it sorted now ...... Quote Link to comment Share on other sites More sharing options...
Pete Ashby Posted May 4, 2013 Share Posted May 4, 2013 Pleased you're got it running now Tim, however if everything is working correctly the lines should not need priming the suction on the pump is more than adequate for that task and can be accomplished by working the hand priming lever (if you have the correct type pump fitted). If you don't have a hand priming lever and are still on 6 volt then you may well not have enough umph in the battery to prime the system through I suppose. When you have a spare moment I would still suggest you check the items I suggested in my previous post as these things have a nasty habit of not going away :-( and letting you down in the most difficult and embarrassing situations I know I've been there :red:) regards Pete Quote Link to comment Share on other sites More sharing options...
deadline Posted May 4, 2013 Share Posted May 4, 2013 Agreed... not do pile on, but my CCKW work in progress sat for 8 months over the winter. I put 2 gallons of gas in the tank, pumped the priming lever less than 20 times and could hear the carb fuel bowl fill up. A properly sealed fuel system will prime quite well with the priming lever. If you can't just hit the primer and get fuel then you have an issue. The system works quite well. If my jeep sits a week I usually have to give it 3-4 primer pumps before I can start it.. but each time I can hear fuel squirting into the carb fuel bowl. I think the biggest issue is that the pot metal valve seats erode and no longer provide a 100% seal. I read a tip on G503.com to put use a fuel safe non-hardening sealant (so you can get the valves back out when the go). I've done that on both fuel pumps and it seems to have done the trick. Quote Link to comment Share on other sites More sharing options...
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