Roosa Master IP solenoid issues on Miller Welder

Have an '81 Miller Wildcat 350D with the Waukesha VRD155 4cyl diesel. It has the 1800RPM Roosa Master IP. Model 3245170 (seems it's that # or the following) C-207634-C. It's 12 volt.

Was redoing the tailgate on my dump truck, went to start up the welder but no go. Not even a faint puff out the stack. There's fuel and power going TO the pump but that's it. Even changed the wire to the other terminal on the IP with no change.

The rig is used sporadically...but during the last half dozen or so times when it came time to shut down...the solenoid has clearly been sticking since even with power cut off to the solenoid it would stay running though roughly since the solenoid was turning off maybe half-way. Would have to tap on the top of the IP before it would finally shut down.


Since 95% of the time when using the welder the panel is always within arms reach...had to bypass the defective Murphy Switch and had rigged the solenoid directly. Had installed a 12V ballast resistor in-line with the toggle switch and solenoid since it was clear after the 1st time that direct 12V was TOO MUCH since it would stick...hard. With the resistor in place it engaged smoothly. This setup was done a few years ago and has ran without incident until the previously mentioned...

Since I would have to pull the top of the IP regardless...does this appear to be the right one? http://www.ebay.com/itm/171755384961?item=171755384961&viewitem=&vxp=mtr
 
The serial# starts with DB and am sure if it matters little but to be sure it is known exactly what pump, the distributor head is ported on the outside closer to the main body, rather than out the back.

Since that first link looks as if it it is showing USED rather than new solenoids...might this be it? http://www.ebay.com/itm/Shut-off-Solenoid-6-2-6-5-chevy-ford-john-deere-allis-IH-Roosa-Stanadyne-6-9-7-3-/281983777220?hash=item41a78af9c4:g:pVwAAOxyOMdS8PKj&vxp=mtr
 
Yes, that should work. Might want to take it apart first to see what is going on. The solenoid only uses power to turn the engine "off", not "on." Spring pressure turns it "on." So it cannot be an electrical problem. Sounds like mechanical linkage is hanging up. Linkage might be outside the solenoid, or inside where the plunger rides. Very possible you can fix it with no new parts.

The resistor thing makes no sense to me. Wiring problem in the charging circuit? The solenoid will turn the engine 'on" even with just 4 volts, so it will not work right if there is any charge feedback.

There are three different designs of solenoids. All can interchange. First design has no plunger.
a165962.jpg
 
"The solenoid only uses power to turn the engine "off", not "on."

Say WHAT?????????

I agree with you, though, about the plunger sticking in the solenoid.

The solenoid, being magnetic, attracts any and all ferrous particles that get near it, I've seen many with little "whiskers" of metal built up around the plunger and coil area.

If the governor damper ring has failed and the governor parts are rattling against each other, it's common for enough particles to stick to the solenoid that the plunger can't move freely.

Also, if there's been any moisture in the fuel, that area of the IP can rust.

That being said, to the IP... pop the cover off and have a look at the solenoid before shelling out $$$ for a new one. They can be dis-assembled and cleaned, compressed air works to blow the metal particles out.
 
It's a very definite "ON" to run and "OFF" to kill the engine in this case.

For the question regarding why I had installed a resistor...

As mentioned in post...when I had first applied full 12V to the solenoid...it would operate it...HARD. Whether this was an end result of wear and tear when the welder saw undoubtedly heavy use in the New Mexico oil fields and so countless ON/OFF cyccles or a defective replacement...IDK. I've only owned the welder for a few years where it sits looking pretty in its fading primer red paint. The resistor appeared to soften how it engaged...no harsh engage.

However now, when it would be used even after turning power off...there was a clear and definite change in how the engine sounded...it would lug like it was starving for fuel which itself was also a sign of the solenoid hanging up. Or I certainly HOPE that is it anyway.

This weekend (today was my Friday) I'll pull the top to see what is going on. Will also see for certain which type it is. Even though new is a tad pricey, I'd rather have a spare and not need it. It will be Monday before a replacement could be shipped anyhow. If salvageable the new might still go in but just keep the old on hand.

Solenoids fouling//sticking...whatever their design/type and application they all function the same. In the end they just operate a lever or or have soft tips to seal off bleeder openings or allow spring backed diaphragms to open, etc. With the very heavy mineral water (and can't forget the iron manganese) at work I get to deal with those latter 2 points quite often...among other more serious problems due to said water.
 
Yes, I said it "back-a*sward." That is what happens when I type faster then I think.

The old solenoids had no plunger to get debris inside. Just an electromagnet that pulled on a metal swing-arm. The newer ones with plungers in a plastic-line bore can stick. Especially, as you mentioned, when the weight-dampener has been broken for two years and the pump is full of ground-up steel rivet powder.
 
You may get the new type high force solenoid that's longer than the original. It can be tricky to install correctly to keep from jamming the metering valve linkage during installation. Best way is to have twelve volts on one terminal with a jumper wire, and another jumper wire to ground on the other terminal, pulling the plunger in. Now the cover will go straight down in place with no worry of having an engine runaway due to jammed linkage..
 
No, solenoids do not all work the same. At least not in the normal context of the meaning of "solenoid." To be technical, a
solenoid is just type of electrical helix winding and no more. Most people I know who turn wrenches or run wires call a
solenoid an electromagnet that creates movement - of a mechanical part, or of electrical contacts.

I was just making the point that the "solenoid" in the Stanadyne DB or DB2 pump is just an electomagnetic winding that pulls
on a chunk of steel. No contacts to go bad. Just mechanical linkage to hang up, or in a rare case, a winding to go bad. More
often when the magnet stops working it is because of 20 cents worth of rubber insulator boots.

That pump likely has a plastic vibration damper inside that is broken causing debris to go floating around and hang up the
solenoid. Or possibly, the fuel metering valve is not working correctly. It is a rotary fuel valve that is what actually
turns the pump "on" or off" and is held in "on" position by a spring. When the solenoid is turned "off" is has an even
stronger spring that pushes that metering valve closed. There is no direct connection between the solenoid and the metering
valve.

You still have me a little stumped with the need for a resistor unless you have some charging system feedback problems.
 

Not sure how charge feedback would be possible with solenoid wire coming straight from switch. Even the push-start (also fed by switch) and AMP light are fed by it. The switch which isn't a modern cheapo....would have to suffer an internal mechanical failure enough to cause random internal arcing of contacts.

Best I can tell because the resistor steps the voltage down slightly and keeps the current even. Just as running without one can burn up some ign coils...or in a somewhat crude but effective analogy...using 12V to start an engine using a 6V starter (ie mid 50s fords). Makes them engage a bit...energetically...and can cause their bendix to jam.

Original wiring through the Murphy box probably supplied lower than battery voltage for all I know.
 

Since other post won't let me edit...

Hence why I added "etc" to to how they work. No magnetic field w/o power...even if you're just using DC to make a nail have poles.
 
I have seen many diesels with Stanadyne pumps have trouble shutting off after an alternator swap was done. I am talking
tractors. I have no idea how your welder is set up. All it takes is something like a Delco 10SI or 12SI wired in, and then
charge feedback into the ignition circuit lets enough voltage bleed to the pump, it will not shut off. I tested a few and it
has to drop below 4-5 volts to collapse. On the Delco swap, a resistor is often added into that field-excite circuit for the
alternator and that is enough to allow shut-down with a gas engine. Often not with a diesel IF it has a Stanadyne with an
electric shut-off.
 
(quoted from post at 06:39:39 07/16/17) I have seen many diesels with Stanadyne pumps have trouble shutting off after an alternator swap was done. I am talking
tractors. I have no idea how your welder is set up. All it takes is something like a Delco 10SI or 12SI wired in, and then
charge feedback into the ignition circuit lets enough voltage bleed to the pump, it will not shut off. I tested a few and it
has to drop below 4-5 volts to collapse. On the Delco swap, a resistor is often added into that field-excite circuit for the
alternator and that is enough to allow shut-down with a gas engine. Often not with a diesel IF it has a Stanadyne with an
electric shut-off.

I came across the same thing on an Onan diesel but in that case it would not shut down at all without intervention.

I have had Stanadyne pumps where you would shut down the power and they would continue to run for 10 seconds to a minute, pulling the wire to the pump made no difference.

Cleaning out the junk floating around in the pump that was on it's way out the door would work for a short while.
 

As far as I know the setup is the same as when it was built by Miller. Not sure on what exact type the alternator is...not about to take apart the cowling to find out since it works. I THINK it is the type that can be found on ~81 fords. Any charge feedback...after thinking it over more...would have to end up through the charge indicator lead from the alternator to the AMP light...then to the side of the switch that the solenoid also attaches. Not sure how that would be though since I would have to be more voltage than the battery to keep the light from coming on.

If I was to power the solenoid any more crudely I'd just run a 12inch jumper wire to the battery box below the radiator. http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=ttalk&th=910433 is a link to another topic in this forum where it shows an image of another gen//welder set (for reference only). The pump is on the right side here..and outward looks identical to the one on the Miller here. It is just on the left instead and its alternator is more modern looking.
 
Just has to have 5-point torx instead of normal 6 holding cover down. Fact they are tamper type doesn't matter as those are the ones I tried. Took multiple tries before realizing WHY the driver wouldn't fit even with careful tapping on its opposite end.

Now to decide if I order the bits before ordering replacement solenoid and so lose a week or do both at once and hope it's the right one.

Is there a way at all to be sure of the exact solenoid type by going by model or serial# on the pump? I know it begins with DB and one of the possible replacements says its compatible with them and other 2-letter types.
 
Okay...after nearly a week of delay because someone in shipping screwed up on my zip code...the 5-point tamper-torx drivers finally arrived...a week after the solenoid did.

I definitely have the shorter one and I think I see where the "minor modification" is located as per the information on the new solenoid when going into the older pumps.

On the underside of the cover there is a raised semi-circle lip in the casting. The old solenoid clears this but the new one almost butts up against the end of the cover. That lip must therefore be worn down to be flush with the rest of the metal on either side?
 
EDIT: (Why is the real thing not working?) But wishing I'd paid attention to the new solenoid listing and just paid the extra few $ for another that would have included the IP top gasket and insulators for the solenoid terminals. Will have to reuse old insulators and the pump didn't even have an O (actually rounded rectangle) gasket when I pulled the top. Fortunately can either make due w/o or just make use of some left over giant O-rings from an early repair attempt at some tractor rams and jam them into place and try to overlap or butt ends.
 
Scratch that. Was a gasket...it just fell out without noticing.

HOWEVER...there is yet another problem that causes delay after delay...that makes you want to tear your hear out (if you have any) or make the thought of putting a big bore round through engine block rather tempting (intellectually only of course). New solenoid casing just HAS to have a crack in it...wish I noticed this as soon as it arrived instead of when install began. Don't need diesel soak ruining it before its time so.....

Commence tirade.
 
Got it sorted out...more or less.

Research of related pump designs have the solenoid foot hooked around the tab while on another it simply works against 1 way and releases the other.
Installed new solenoid...arrangement seems the lever presses on a tab on the slide below (forget name of the part) to press it into OFF position when no power to solenoid. Power on releases pressure to allow the slide to move on its own into RUN position.

However the slide seems to be jamming. Could barely move it by finger at first...but it freed up and seemed to work smoothly. Finally got it started but when attempted shutdown it STILL wanted to stay running. After several long seconds it started to shut down but took previously mentioned tapping to get it to shut down fully.
 
Your metering valve or governor linkage is sticking.

Should have figured out what was sticking and cleaned/honed/repaired it before putting the top back on.

There's a long screw/pin that the governor spring assembly has to slide on.That may be rusty/gummy, as well as the metering valve itself.

Pray that it doesn't get stuck at a high fuel rate!

<img src = "https://assets.hemmings.com/story_image/119462-500-0.jpg?rev=2">
 
The pump itself was never pulled in the 1st place. Only pulled pump top to replace the solenoid which was indeed bad...powering up there would be a spark and for it to actually engage require assistance. Unfortunately without removing the whole top shroud of the welder set I can't get a direct look-down into the pump to get a good look. I had ORIGINALLY thought it was just the solenoid sticking...but since it stayed running like it did during recent uses with new solenoid...all this is at this point is troubleshooting. For all I know maybe the solenoid foot isn't quite installed right...thus causing the CURRENT (not past) failure to shutdown right away.

Didn't get the chance during proper daylight when all was put back together...had to use a floodlight for overall and high power flashlight to see in. Be going over it again tomorrow since I'll finally have the whole day to do it instead of just the few hours after getting off work.

One thing I'm also trying to get confirmation on is if there might be a tab that the solenoid foot hooks around to ensure proper operation (saw a cutaway of a newer Stanadyne-type) that had this while another old one near this ones vintage looked as if the foot merely worked against the tab going 1 way and sits clear of it going the other way. If the pump were mounted on the right side of the engine this would be easier to see if it did...but its not. Sadly most all the older pumps I've come across to try and see all lack solenoids for me to try and find out...they have external means via cable.

A PO had set the throttle to lock in at or near its governed rate even though the linkage chain to the automatic speed control solenoid is still in place...and whether IT still works I've no idea (or even if a replacement is available anymore). Hasn't cause any issues during the few dozen times over my 3 yrs of ownership of the rig. Been the last half dozen or so uses the sticking has crept up.

I hope it doesn't runaway either. My only hope to shut it off would be to try and quickly remove the supply line...or manage to somehow choke it off if tapping doesn't do the job.
 
"One thing I'm also trying to get confirmation on is if there might be a tab that the solenoid foot hooks around to ensure proper operation (saw a cutaway of a newer Stanadyne-type) that had this while another old one near this ones vintage looked as if the foot merely worked against the tab going 1 way and sits clear of it going the other way."

Almost certainly that's the way it is. When the solenoid is energized the tab retracts out of the way of the metering valve linkage travel, when power is cut it moves in an arc by spring action and shoves the metering valve linkage to the "zero fuel" position, NO hook or direct connection involved.

"My only hope to shut it off would be to try and quickly remove the supply line."

Actually, with this IP the quickest emergency shutdown would be to pinch the return fuel line 100% closed with a Vise Grip!
 

Will be pulling the top off again to see if the slide is stiff once more and figure something out. Been watching an instructional (see link below) on the disassembly on a pump whose only difference is the throttle lever is on opposite side that has been has been informative.

https://www.youtube.com/watch?v=MpsJma1nvGg&amp;t=583s

Also the return hose had deteriorated inside...fuel still could flow back up but only through 99% blockage in a hose that felt HARD. Only reason I know fuel was making it through because after disconnecting end from pump...it took awhile to dribble drain. That is now replaced with short injector hose stubs on either end and copper tubing between. All that restriction I'm sure didn't help...back pressure.

As long as its just the upper assembly jamming due to grunge then if I have to I suppose could pull it where the pump sits.
 
Just thought of it...instead of vice grips on the return line....a small valve...ie needle type put in place just before line going back to tank. IF it tries to runaway...shut valve. Be faster than trying to hunt down vice grips unless they are already in arms reach.
 
Good new...for time being anyway. I think what was happening that since the new solenoid is longer I couldn't quite just set the top back in...the rear of the solenoid would impact the housing. I used a skinny screwdriver to move the slide towards OFF and set it down. This was probably lifting upwards on the metering rod arm. Also when I pulled the top it also would rub on the tab so when I tried moving it by finger at first it would be stiff. However if set down completely it works smoothly.

This time I got it ready and held the solenoid plunger back then lowered into place. I also bypassed the resistor that was previously installed when I had the impression the old solenoid was being moody...so the new solenoid gets full battery power now (and possibly makes its shutdown a bit more energetic). 2 start ups...2 shutdowns...and the normal 1 maybe 2 seconds of run as the slide finishes closing and inertia ceases.

No need to re-enact Edgar Allen Poe's THE RAVEN on the pump.
 

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