Another Stupid priming question

[jasco]

Installed my electric fuel pump and now I can't get the RV started. I know the pump is getting fuel all the way to the IP. I pulled the line and there is diffenetly fuel. The IP or fuel rail is aso returning fuel (I pulled that line too and it is flowing). It started for a few seconds and then died a couple times and now it just cranks. Cracked the rear injector line and cranked it a few times, but no fuel coming out. Drained the battery last night and had to put it on a charger. My question is how long should I expect it to take to purge the IP and Injector lines? At what point should I stop trying to start it and start looking at other things? Will starting it with the accelerator to the floor help? What other things should I look at?

Thanks,

Matt

RV started like a champ just prior to starting the work.

 

[jimraelee]

there must be a crap ton of air the in lines... crack alllines and spin the engine. I usuailly dont crank more that 5-8 sec at atime, giving 20 sec break in between.

 

[jim_22]

Are you sure there is fuel squirting out after the fuel filter when you crank?
This narrows down the issue quite a bit.
Holding the accelerator down helps let more fuel through (but pumping does no good, except psychological).

 

[TWeatherford]

Make sure the fuel shutoff solenoid is getting fuel... even if you didn't mess with it you could have bumped it in the process. I just crank 10-20 seconds at a time, full throttle, letting rest a minute or so in between, and I like to keep a charger on the batteries the whole time. You can disconnect the fuel return fitting on the ip, crank and verify that its coming out of there, that way you know you have fuel to the ip. After that its best to crack all the injector lines. Once there is fuel around all of them, snug them back down and you should be running. Last time I did this it only took 5 cranking cycles between and empty IP and a running truck, and thats with a mechanical pump, not electric.

 

[MIDNIGHT RIDER]

Drained the battery last night

Even with a perfect fuel-system, the battery(s) must be strong enough to crank with authority to start a compression-fired engine.


That being said, the way you describe the engine starting, then dying and refusing to start again, it reads like a fuel starvation issue, either from sucking air, sucking a fuel line together, or something obstructing the flow of fuel on high demand.

 

[RLDSL]

make sure to loosen all the lines at the injectors a few turns. Floor it and crank the thing while someone is watching, if fuel starts to come out of one of the lines, tighten that one down, it may go quick, or you may have to stop and put a charger on the batts 2 or 3 or more times before it fires. There is no science to it. I've had them fire to life after tightening down 2 lines before on a fresh rebuilt engine where the pump has been bone dry , and I've had pumps that were full where the lines were just removed to change injectors take a day and a half.
If it's real ornery even an e pump usually doesn't put out enough push for some reason ( I imagine they go into internal bypass )and I have a rig for priming that I made from a outboard boat fuel tank with a boat lone with a primer bulb on it with a fuel filter installed in the line. I set that tank on the roof for a gravity feed and attach it directly to the pump and have someone floor it while cranking while I pump the bulb like crazy and it builds more pressure than an epump and it forces the fuel right on through and it will usually have the things firing with fuel spurting up around the injector lines at full pressure so wear eye protection.

 

[Agnem]

From the description of the work you did, there should be no air in the injector lines. How did you tap power for the electric pump? I'm suspicious that your FSS is not working. Is it clicking when you apply and remove power?

 

[jasco]

I'm pretty sure I put a hefty dose of air into the system. Like an Idiot I did a bit of cranking before realizing that the pump and lines were not fully primed. I think the short running it did do just emptied out what was in the IP and inector lines.

Power for the pump is straight off the battery to a 30A relay with a fuse between the battery and relay. Relay is trigered by the GP controller. The post at the back that has 2 or 3 red wires connected to it. Checked with volt meter to pick the right one.

I'll have to check the FSS tonight. Does it have power all the time when the ingnition is on?

Thanks,

Matt

 

[MIDNIGHT RIDER]

From the description of the work you did, there should be no air in the injector lines. How did you tap power for the electric pump? I'm suspicious that your FSS is not working. Is it clicking when you apply and remove power?

Power for the pump is straight off the battery to a 30A relay with a fuse between the battery and relay. Relay is trigered by the GP controller.

I'll have to check the FSS tonight. Does it have power all the time when the ingnition is on?

Thanks,

Matt

I tend to agree with Mel to some extent.


Also, I am not understanding this glow-plug controller business that you trigger the fuel-pump relay with.

Is this trigger source HOT at all times the key is in RUN position ??


The FSS should be HOT at all times the key is in RUN; turn the key OFF and the FSS stops flow of fuel in the I-P.

 

[jasco]

Pulled the line before the IP and let the pump run. there was still air in the line. I think it is mostly cleared now. Engine will start after a bit of cranking, but then dies after a couple seconds (have to feather the accelerator pedal to keep it running at all). I was able to do this 3 or 4 times tonight before the I had to give up for the evening. Checked the FSS and it is working. May still need a bit to get a full prime. I could also have air entering the system somewhere. I'll try again tomorrow and see if I have better luck. If not I'm going to have to go over all of my plumbing. Does anyone know where i can get a sight glass so I can see if there is any air in the lines before the IP?

Thanks,

Matt

 

[jasco]

I tend to agree with Mel to some extent.


Also, I am not understanding this glow-plug controller business that you trigger the fuel-pump relay with.

Is this trigger source HOT at all times the key is in RUN position ??


The FSS should be HOT at all times the key is in RUN; turn the key OFF and the FSS stops flow of fuel in the I-P.

connected relay to the post with the three red wires at the bottom of the pic. I think that is the switched source. Please correct me if I'm wrong.

Matt

 

[plywood]

Yep, that should have power with key on.

 

[jasco]

Yep, that should have power with key on.

Thanks,

I think you probably told me to use that one in another post. it really is a good spot. No splicing into wires. Really easy to get to in a van too.

 

[RLDSL]

Not sure where you can get a sight glass, but a goot independant motorcycle shop will have some transparant fuel line that you can put on there so you can see what's going on. It'll be a rather stiff stuff, can't remember what's its made of, teflon base or something but its not that wimpy vinyl stuff.

 

[redneckaggie]

check this thread for the collapsing problem that i had it would cause symptoms like you are explaining.

http://www.oilburners.net/forums/showthread.php?t=36264&page=2&highlight=carter+pump