All,


As you may have seen, I had installed a CAT filter post-OEM. http://dieselplace.com/forum/forum_posts.asp?TID=3511&PN=2 I changed the OEM filter at the same time. The past couple of "cold" starts, I noticed a engine stumble, but then the truck would run fine after that. Yesterday after work, the stumble was pretty bad, so I shut the truck off and bled from the CAT getting a minor bit of air out. I also cracked the OEM after bleeding the CAT, and no air.


This morning though, it started and as I was backing out of the garage, die it did. Bled again from the CAT and then the fuel rail service port on the front of the engine. Good amount of air from the CAT, little bit of air from the port.


The truck has always ran fine after being bled, so that is fine. I know some have resorted to the lift pump setup to cure this. I, like most, do not want to have to bleed constantly, and would like to avoid the pump. Could something be wrong? One thing I did not do was pre-fill the filters with fuel, although I doubt that is the case. Have some here had better luck not bleeding and without liftpump installs? (VR or Frank if I recall correctly??)


The post-OEM setup is what I want, but without the issues. I am sure I can get this sorted out, but could use some of your guidance.


Thanks,
MN.

sounds like air is getting into the fuel. double check all your fittings of your filter install. also did you replace the rubber o-ring on the oe filter and the water sensor. i think checking for air at your fittings on the supply side you wont get leaks becaues that side of the system is vaccum. just retighten and look prime the oe filter 30 times then crak the bleed do this 3-4 times as with a break system and air in the fuel will rais havoc in the fuel. good luck

Agree, you didn't get all the air out initially or the air is getting in somewhere. Should be no need for a lift pump. I bleed mine after install about 150 pumps on the OEM filter housing to be sure all the air was out. Has not skipped a heartbeat in 5-6 months since install. Just open the bleed screw on the housing a little and pump the SH&^ out of it until you see no more bubbles in the fuel coming out the bleed port. Start and should be good to go. If it does it again you have to check/tighten all the fittings you installed. Something is leaking and sucking air into the system.


Go back through the install instructions and see if you missed something. Don't add anything else until you find the problem as you will just keep having the same issue until it is solved.


Good LuckEdited by: Chevysrus

All,


As you may have seen, I had installed a CAT filter post-OEM. http://dieselplace.com/forum/forum_posts.asp?TID=3511&PN=2 I changed the OEM filter at the same time. The past couple of "cold" starts, I noticed a engine stumble, but then the truck would run fine after that. Yesterday after work, the stumble was pretty bad, so I shut the truck off and bled from the CAT getting a minor bit of air out. I also cracked the OEM after bleeding the CAT, and no air.


This morning though, it started and as I was backing out of the garage, die it did. Bled again from the CAT and then the fuel rail service port on the front of the engine. Good amount of air from the CAT, little bit of air from the port.


The truck has always ran fine after being bled, so that is fine. I know some have resorted to the lift pump setup to cure this. I, like most, do not want to have to bleed constantly, and would like to avoid the pump. Could something be wrong? One thing I did not do was pre-fill the filters with fuel, although I doubt that is the case. Have some here had better luck not bleeding and without liftpump installs? (VR or Frank if I recall correctly??)


The post-OEM setup is what I want, but without the issues. I am sure I can get this sorted out, but could use some of your guidance.


Thanks,
MN.





To my knowledge no-one to date that has any manufacturers Filter installed PRE-OEM has an air problem.


I know this has been discussed in great length.


IMHO a PRE-OEM install will give you the same benefit as a Post-OEM install without any of the headaches.


Try replumbing the install under your hood making the CAT the first filter and the OEM the second one. Maybe you can solve the problem.


Thttp://www.dieselplace.com/forum/smileys/Confused.gifNYEdited by: GMC-2002-Dmax

nassdmax,
I am running the same mounting system you are with a Cat 750 filter & a Perma Cool head, & with 4 months & about 3,000 miles of service I haven't had any air problems. You have apparently got a vacum leak in your installation.It doesn't take much of a leak to cause the problem you are having.

nassdmax in your pics it almost looks like you used teflon tape to seal the threads (if not I apologize now). If you did, that may be a source for a vacuum leak (you need to use a liquid/paste sealant). My Racor 660 was missing the filter gasket on my initial install and caused a vacuum leak (no problems since adding the gasket--2,000mi.). Like everone else has suggested check all your fittings & gaskets. Hope you find the problem!


Josh

I appreciate all of your responses.


I know the filters are good and tight, with new o-rings in the OEM also, and light grease on all the gaskets for that good seal.


Before #1 - if it still starts good after this mornings bout tonight when I go home, maybe no issue, if she stumbles still...


#1 - If it means a good bleed, then I will open the bleeders up and pump the sh*& out of it as Chevyrus has suggested.


#2 - I have never had an issue with teflon tape on other joints, but I know how "sensitive" this system is, so this may be my first... If I still get air, that's one I will go after. Any issues with barb fittings and the wide clamp? I always tighten to the point just before the housing starts to get cut.


#3 - permacool head may be less prone to air? if it comes down to that... $35 and I will change out.


I agree with you all that a lifter should not be necessary, and I would not like to post-OEM the filter. Thanks for the advice again, and I will keep you posted...


MN.

All,


As you may have seen, I had installed a CAT filter post-OEM. http://dieselplace.com/forum/forum_posts.asp?TID=3511&PN=2 I changed the OEM filter at the same time. The past couple of "cold" starts, I noticed a engine stumble, but then the truck would run fine after that. Yesterday after work, the stumble was pretty bad, so I shut the truck off and bled from the CAT getting a minor bit of air out. I also cracked the OEM after bleeding the CAT, and no air.


This morning though, it started and as I was backing out of the garage, die it did. Bled again from the CAT and then the fuel rail service port on the front of the engine. Good amount of air from the CAT, little bit of air from the port.


The truck has always ran fine after being bled, so that is fine. I know some have resorted to the lift pump setup to cure this. I, like most, do not want to have to bleed constantly, and would like to avoid the pump. Could something be wrong? One thing I did not do was pre-fill the filters with fuel, although I doubt that is the case. Have some here had better luck not bleeding and without liftpump installs? (VR or Frank if I recall correctly??)


The post-OEM setup is what I want, but without the issues. I am sure I can get this sorted out, but could use some of your guidance.


Thanks,
MN.





To my knowledge no-one to date that has any manufacturers Filter installed PRE-OEM has an air problem.


I know this has been discussed in great length.


IMHO a PRE-OEM install will give you the same benefit as a Post-OEM install without any of the headaches.


Try replumbing the install under your hood making the CAT the first filter and the OEM the second one. Maybe you can solve the problem.


Thttp://www.dieselplace.com/forum/smileys/Confused.gifNY





I have had one of the manufacter's filter setups in a pre-configuration and had to bleed the system every other tank of fuel to avoid air issues as well. My cure was to mount my pre-OEM filter in the "nictane" location. No more air problems. Could be that my quick disconnect line was leaking and now that it has been removed, the problem has resolved it self.

Perhaps the air is being trapped in the HIGHEST point of the system? The stock OEM and the NICKTANE locations are all lower in the system, allowing the air to pass until it accumlates enough in the high spot and then sends a slug of air and kills the engine.


I am not sure but all the things I have been reading the OEM is the highest piont in the system normally. The air bleed piont is there and it may hold a greater amount of air than your installation.


I do think pre filling the filter and getting as much air out as possible first will greatly help.

well now I am stupmed. After getting home last night, I pumped and bled the system quite well. I took her for a spin, and I still found air in the system. After that I took Josh's advice for the teflon paste sealant. Did a run to a meeting, ran back and checked for the presence of air.....NONE. I was feeling real good this morning when there was no stumble.

I ran into work (~1 hour) and she sat outside until lunch. She started with a stumble and then die again. grabbed the wrench and rag, and bled the air out, running again.

Tonight I am going to put a fitting between my two hoses at the filter (taking the filter out of the loop) to see if I still get these issues. If so, it is the head and not my other connections to the OEM nipples.

This does bring one thought though... Of who has used the CAT head, what sealant did you all use for the gasket between the cover and the head?

I'll get this eventually, just don't like bleeding at 7 degrees with wind howling up my backside.

MN

nassdmax that sucks! Sounds like a good idea to use a nipple and take the filter out of the loop. If you have the recources, you could put a Schrader valve on the filter unit, plug the other ports, pressurize the unit and stick it in a bucket of water and watch for bubbles. Or you could use a vacuum pump on it to see if it will hold a vacuum. Good luck!


Josh

Hi,


i don't use any sealant between the cover and the head (if you mean the block-off plate for the priming pump). i just use the CAT gasket. the O-ring boss fittings don't require any sealant either. as for the filter media i just put a bit of oil on the seal when i screw it on..

I do the same as you Nick. Good to know that there are no issues there.


I will do the bypass deal tonight. Run her for a while and see where we get. If all goes well, then it must be the CAT and not the other connections.


The suggestion of using air to "pressure test" is a good one. Just regulate the pressure low enough to not cause harm. On the other hand, the primer pump is capable of getting the pressure in the filters pretty high, and I still haven't seen any wetness around any joints.


Thanks again, MN.

nassdmax,


I do after 8-9 days of good running seem to collect enough air to start the stumbling you mention. If I don't bleed in a day or two after the stumble I will have a stall like you.


I'm a little lost on this. Either there's a bubble somewhere in my system that I never quite get out and the setup of our fuel systems exacerbates the bubble to a troublesome size after X amount of run time or my filter head is leaking. When I moved from the airbox to the alternator locale I left the feed line in place and ran OEM for a little over 2 weeks with no issues so i know that lines good.


So if I have a small leak, it takes it a while to build up enough air and it's coming either from the out line of the OEM to the Cat or the Cat head itself. I'm considering the PermaCool head as well(I'm thinking maybe the flatter head design might be more friendly to our vacuum systems, or even considering trying to get Kennedy to part with just one of his filter heads he's having made for his new Cat setup to see if it makes a difference.

Nassdmax, I'm posting again on this thread for 2 reasons.


One is to report that I have journeyed down to the dealer where I bought my truck, and to the much larger dealer here in town.


Showed a print of your setup to both Ser Mgrs, and both responded that they liked your setup and both made copies of the printout. Both stated that theu could see no reason that this would affect warranty, and that GM should be happy that you were trying to improve filtrarion. The regional man from GM hasn't been in yet, but my tech friend will call when he is in town.


My other reason is to get this thread back on page one and request that you keep us filled in on your air problems.


It looks as if the cat filter is the highest point in your setup, is there a bleed port on it? Also, how do you get air out of the line from cat filter to the pump? Could this be the problem?

My Racor is mounted under the airbox. No air issues since installed about 8 months or so ago.

Thanks guys... I don't know what I did wrong, but I am going back at it soon. I for now have removed it from the system and I have not had a stumble yet. Obviously something wrong with the CAT head, filter, or my connections at the head.


It is good to hear that Hoot and others with the POST-oem setups have had no issues (although non CAT head). Maybe there is something to do with the height here that we are all missing, but then again, where is the air in their setups.....HMMPH. Frank Blum has his up in the same spot (although not a CAT head), as well as others and I have heard nary of a complaint. VR seems to have my issue on a lesser scale with his CAT head. Makes me wonder if it is the CAT head design in the post-oem position. Anyone else with a CAT head up high?


Could it be that the high cat head traps the air before it is "recycled" to the tank as is the case with the OEM. My theory is that there is always air being "generated" and it is taken care of because it is recycled to the tank through the return lines. Am I all wet??


My next step is to pressure check the head and fittings with PSI and soap. If all is good there, I will find a new lower location rather than buy a new filter head. Any other suggestions?





Dirty Old Man,


Good to hear your news. That would be a great thing to have IN WRITING that there is no effect on our warranties. As far as the bleed, there is one at the "top" of the cat head. I can bleed just that and get the truck running fine. To do a total bleed, there is a fuel rail service port just below and to the left (if your looking from the front of vehicle) of the Alternator. I can get a bit of extra air out there, but it does not help the situation as I always got more air out of the filter head.





Thanks guys... Feels good to sound off.


MN

NassDmax, I have the Nictane Cat mounted in the usual position Pre-OEM (left rear fender well with the Nictane bracket), so it is as high as anyone else's using this setup. Have never had a stall or a stumble (we're talking aboutb the truck right) since the minute it was installed and we fired it up after pumping it for about 15 minutes or 100+ pumps.


If you have the same setup, it would seem that the connections is where you should look. Something is sucking air past a fitting or connection. It would be rare for you to have a defecive head, but I guess that is possible. I don't think that mounting location is the problem by itself as there are a lot of us that have the same setup with no problems.


Has to be a connection somewhere sucking a tiny bit of air that builds up over a few day or two.


Good luck, you will find it!

nassdmax, It looks like your filter is higher than the OEM just like mine. I installed an air bleed in the top of my filter on the discharge side. If you don't have one that is the problem. I don't use the OEM bleed at all when changing filters. The bleed on top of my secondary fills the filter and line all the way to the pump. I have done several of these without a problem. There is nothing wrong with Teflon tape except it will contaminate the system if you have to remove it. Later! Frank

nassdmax, It looks like your filter is higher than the OEM just like mine. I installed an air bleed in the top of my filter on the discharge side. If you don't have one that is the problem. I don't use the OEM bleed at all when changing filters. The bleed on top of my secondary fills the filter and line all the way to the pump. I have done several of these without a problem. There is nothing wrong with Teflon tape except it will contaminate the system if you have to remove it. Later! Frank When you install a new fuel filter, do you fill the filter up with fuel before installing it to cut down on air ?.

I have the bleeder on the discharge side. It just doesn't look like a petcock, but rather a bolt. Thanks for the sanity check on the teflon.


As for pre-filling, I did not, but it shouldn't matter because you are filling with the primer. It just would cut down on the amount you have to push that bulb. Maybe I am all wet...


I am going to give her a shot once more in the current location, re-doing the connections again. If I still get the stalls, I am going to move it low in the system. Maybe this will prevent a suction of air into any leaking joint, because there will be gravity pressure to hold fuel there. If that doesn't work, I will scrap the CAT head and move to a permacool or racor head. What is the permacool head part number???


My Dad has seen this and he feels the same that way I do, coming from a completly blind look. He is a ASE cert, Master Diesel mechanic that is quite good and sought after in Western NY.


Thanks, MN

nassdmax, I have been following this thread since you have posted your photos and writeup. I have purchased the Cat stuff and then tried to find the other misc fittings elsewhere to no avail. I went back to cat and found the stock boy had stuffed a wrong fitting in for the pieces that go into the in and out of the head. The parts guy on the computer decided I had the wrong fitting and went in the back and found them. He helped me get the hose fittings and elbow.I asked then if I should use tape on those fittings and was told that the O ring would seal it when snugged up. The bleed nut also has an O ring that if missing would not leak fuel while in operation due to a "suction" type of setup with the pump (or when the switch is off since it is higher that all else) but will allow a slow leak to allow the fuel to drain toward out of the top of the filter when sitting.


Another thought is as to whether the line running to the fuel rail has a sag in it like a big "U" when it goes across the engine and under the black "thing" which would be an area to trap air on the pump side.





My 1/2" hose came in yesterday and I have to find some scrap to make my bracket and I will duplicate your idea successfully I hope!


Good luck


Hoagie

FYI: Certain manufacturers will void warranty on their products if teflon tape is used.


Suntec is one of those companies. These fuel pumps generally operate under 150 psi, in residential and light commercial applications.


Not sure I'd want it contaminating the fuel system on my truck...


That's all on teflon tape...


Suction leaks are a bitch. That's all there is to say about that. There are a lot of quick disconnects in our fuel system...

Some trucks just seem more prone to this. I've had guys swap filter setups to their new trucks, and some inherited problems not there with the old one, while others have lost the problem.





One thing's for certain, vacuum draw systems SUCK....

Hoagie, The o-rings are all in place. Good luck to you and please do post your results with your new setup.


There is always the option of making it a pressure setup..... A 6.5 lift pump would do it, but I'd rather get the problem solved right. If I get it down to a stumble once a week, I would probably add some pressure.


This weekend is going to be the re-do everything and try it again, then when that fails do something different weekend. What fun, NOT!


Thanks for all your encouragement.


MN

Just a thought..........Being that this is a post OEM setup, When you bleed the air out of the Cat head it only bleeds the line from the OEM hand pump to the CAT head, correct? Where does the air go that is in the long fuel line from the CAT head to the motor?


Once the system is bled for the very first time after install, wouldn't the exit line from the CAT head still be full of air?

Update... I had generally checked things over yesterday, and noticed a wetness at the bottom of the OEM filter. This is never good, so I removed the OEM and re-did all of the o-rings. Tightened her up good and no leaks. At the same time I put the CAT back in line. Bled only from the CAT head.


I did fill up the filters before I installed them this time. I noticed that the filter was down 2-3 inches from the top. Source of air trap?? Possible. I also removed, filled, and re-installed the CAT filter. We will see how this goes. All connections are tight as far as I can tell. If this doesn't work, I am going to have gravity do my work for me by putting the CAT as low as possible (under airbox most likely).


KEVTECH, Great thought, and here is my theory on this... The fuel system is always recirculating the fuel back to the tank. Some air is acceptable and does get sent back to the tank normally. a little bit of air should be able to flow back to the tank, it just needs to be small enough to not break the vacuum. In the case of the very first time bleed, I actually bled from the diagnostic port near the alternator.


MN

Nasdmax,
Any word since you did your reinstall. Have you learned anything new about do's and don'ts of your install.
Any suggestions for removal of the hoses from the factory setup other that pliers on the clamps and pull.
I have finished fabricating my mount. It is really tight in there. I have a 2001 2500HD and the hood seems to be more streamlined(lower profile) than some of the other HD models. Maybe it is only my imagination?
Hope your bleeding has been stopped!! and all is working well. Hoagie

I just installed the Nicktane filter setup over the weekend and have several items of interest. First of all, I have a transferflow tank and found that I had to drop it in order to get to the quick disconnects. Even then it was a b***h. Secondly, prefill the Cat filter or you will wear out your thumbs on the oem pump.


In my opinion, the QD's do not appear to be a good solution for a vacuum system. Since it appears that noone is having air problems with the pre-oem Nicktane system, perhaps it is the removal of these 2 QDs from the system that is solving the problem.


I would seriously consider removing the hose from the tank to the cooler and replacing it. That may solve your air problem.

Well it is -42'C (-44'F) here this morning without the windchill & my truck & CAT setup are purring like a kitten. No troubles with my setup since install about a month ago. I am not using any fuel additives since I have not had any prblems so far with the cold weather or gelling. I think the fuel here in Canada already has additives for the cold.


I found the easiest way to take off the hoses was with pliers on the clamps & then pull & twist. It does take some time to break the seal.


I know for sure that the 2001 hood is different than the 2002 & 2003. I just ordered a new cowl induction hood for my 03 & the specs said it would not fit on a 2001.Edited by: KevTech

Unfortunatly the bleeding never stopped. I had to remove the system to take a break for a while. It was getting so I needed to do a bleed during the day in suppliers parking lots, and they are the last persons that I want to see a chevy having an issue. The attitude of "We GM are strong like bull, you must supply great parts for strong bull" just gets diluted after seeing a guy bleeding a fuelsystem after telling them that! :)


I had made sure the system was airtight via means of a pressure test. I did try to move the CAT to under the airbox, and that didn't work. It actually got worse. I have had it off the truck for about a week now and no issues. I think my system is just cranky. Kevtech has it working no issues.


My next move..............Permacool head?? I don't know why I think this, but I feel the CAT head is designed in a way that just a small bubble of air will prevent the fuel flow, and I believe that all of our systems are running on a diet of air. I don't want to discourage anyone from doing this with a CAT head. It has worked for scores of people in the pre-OEM nictane setup without issues. I don't know where else to turn.


MN

Is it possible that there is a tiny hole or crack in one of your fuel hoses, fitings, CAT filter or base? Just a thought since it may be small enough to not let fuel leak out but big enough to slowly let air in under vacuum pressure?


What if you start simple & replace just one hose at a time, then one fitting at a time & then finally the filter it self. Maybe this will lead you in the right direction. Seems like there is a very small air leak somewhere in your setup.


For some reason I don't believe it is the CAT head or myself & others would be having air problems.


Edited by: KevTech

Hose is cheap. I'll give it a shot because it wouldn't hurt. What thread sealant is everyone using? Maybe I got a bad batch of my PTFE paste. Would a Loctite form-a-gasket be better, or something else?


Thanks, MN

I used the white thread tape without any problems.

Loctite Hi-Tack gasket sealant works very good. Follow the instructions on the product. http://www.dieselplace.com/forum/smileys/Approve.gif

While it may be a leak, it is more likely vaporization (boiling) in the lines. Particularly in the EDU.





Been down this road MANY times...





Putting a lift pump on and keeping it under pressure has eliminated any air collection in my filters. I never had any starting issues, but always air. They all do until pressurized...

I used the white thread tape without any problems.


I posted before that teflon tape on fuel sytems is a no-no. Voids warranty on low pressure fuel pumps, let alone the Duramax...


Just pass it on, as I know of SEVERAL denied warranty claims on SUNTEC fuel oil pumps due to usage of teflon tape...


Ty

Thanks Tysmith, I will be removing my teflon tape.

Put and o-ring between the filter head and filter on the nipple. air can leak by the threads. Went through this when I mad a Cat system for the VW TDI's.

Greg

Greg,


Are you saying at the 1-14 thread center post on the filter head? Seems like air would not get in there, just switching between the out and inlet.

Yes thats where I mean. depending on the fit of the thread air can leak through. I have been there and done this on my VW TDI Cat filter system that I sell.

Greg

Matt,


Long story-happy ending.Have followed the alternator location discussion for the filter and how you had issues with air. I decided that maybe your location was right for me and that I would be luckier than you. I installed a filled cat filter, tried to blead the lines from the bleader nut on the cat mount after pumping a few pumps on the factory primer and kept turning the cat bleader until finally the nut blew off and hit the the hood and fell in the yard spraying diesel all over me and the engine compartment. I then figured that bleading could only be accomplished with making sure the o ring didnot stick down in the hole- I figured it would move up as I twisted it. Pumped slowly to get the lines full with fuel and closed it back up. PUmped and blead from the schrader valve. Started right up. Next morning everything worked fine. After that every evening before going home and in the AM before work it would start, run 14 seconds, and stall. I would just pump the factory unit 10 times and get back in and start it-after about 4-5 seconds of cranking. Did this for two weeks straight.


I decided I must have a leak so I tightened everything some more. Then decided to put silicone II (high temp up to 400 degrees)on all fittings. No real difference. I posted for help on a check valve idea including whether there may be one in the cat bleader and am waiting for someone to send me one to check it out.


I decided to try something else. I originally had to special order fuel line from an auto parts store and got the whole roll for about $30 for 25 feet. I had been looking and reading and decided that with the outgassing idea and the fact that the line from the cat filter was all down hill and eventually back to the tank that maybe it was draining from that half of the of the line and not having anything there for the pump to draw on after its few drops left in the pump. This down hill was the opposite of the factory setup where the hose is uphill from the factory filter to the pump with a check ball in the factory filter head that keeps the fuel in that part of the line.


What I tried was a different route using the remaining fuel hose. Routing it from the cat filter head out in a U shape and back parallel and under the radiator hose I went out behind the driver side headlight. From there I cut a small corner off of the black molding with my leatherman saw blade and routed the hose(Put duct tape over the end before starting cause you have a few blind feeds and need to keep it clean)across the front between the grill/bumper and the radiator area making sure that I was below the level of the pump for as much as possible, across and behind the passenger headlight and into the area where Hoot installed his filter below the air box. From there I snaked it up through tight with the wheel well and out near the other hoses that run just inside the well. From there I went outside(from the engine) of the intake pipe, right next to the factory filter primer and back through the original path taken by the factory hose. Pumped afterwards about 50 times to fill this long piece of hose. Since then I have not had a single stumble stall(5 days).


I know that you mentioned that hose is cheap and I wanted to avoid any need for a lift pump. This long route around and below the level of the pump is working and a lot cheaper than buying pump and hardward, and switches.


Hope this helps,


Hoagie

What a way to do it. Odd and unconventional, but if it works, that's great. Too bad you had an issue to begin with, and now you see how batty I was!


I do have mine back on now and have installed a gasket on the threaded center nipple. I think Greg may have been on to something there. It has only been on a couple of days this way, but we'll see.


The more and more that I think about this, the liftpump may be the real way to go. Get rid of the air issue completly and not mask it by strange routings and different heads (not that there is anything wrong with either).


Later,


MN

It is interesting that some brands of engine mounted filters are having air problems when the Racor doesn't. It is also interesting that some filters don't have a discharge side air bleed. There is no way in hell to get the air out unless the bleed valve/pet cock, drain cock etc. in the right place. It takes 70+ strokes on the OEM filter pump to expel air and fill the Racor filter with fuel. On one install it looked like I was getting straight fuel after 55 strokes. I shut the valve and started the engine. It promptly stalled. I open the bleeder and gave it about a dozen more strokes. This time it started and ran normally. Moral to this story is to get all the air out to start with. Later! Frank