"new" 93 wont start....please help...

[Uncle Joe]

HI there great diesel gurus

I just picked up a 93 5 speed and it wont start up, it shows 250k so I whold think the comp is still good, it does get fuel to the injectors (loosened the nut and fuel came out), there is power to the shut off solonoid.

It cranks fine yet wont start..... any Ideas?

Amy help will be apreciated!... ... ... Joe

 

[BushWakr - RIP]

I know you've checked the fuel supply at the injectors but it should be a fairly vigorous blast of fuel when the nut is loosened.

Next, the start/stop solenoid has two wires attached to it. One is black and, one blue.

One wire carries an initial "trigger" voltage that is 12 volts... this in turn activates the solenoid... then once the truck is at or over cranking voltage the second wire provides a maintainence voltage. . I believe it is stepped down to 10 VDC.

Do you have those cirucuits operating correctly??? If not, you may have a sensor that is faulty. . or the solenoid is failing/weakening.



Since I really suck at electrical things, that's about all I can offer on this particular aspect. Maybe a couple of the other guys can jump in here and help with other diagnostic suggestions... . yes, this is a test you guys... .



pastor bob... .

 

[bgilbert]

How long has it been since it ran? Sounds like air in fuel, or s/s solenoid as Bob said. Do you get smoke from the exhaust or not when engine is cranking? Need two sets of hands, one to crank the starter, one to crack open each injector line one at a time, check to see if inj pump is pumping sufficient fuel to each inj, plus this will bleed off any air that may be in the system. Fuel filter clogged? Water in fuel? Fuel in tank? Its all just nuts and bolts, mechanical engine, can't be too tough Let us know.

 

[Jdonoghue]

I know you've checked the fuel supply at the injectors but it should be a fairly vigorous blast of fuel when the nut is loosened.

Yep, you should get lots of fuel with the lines cracked at the injectors - when I put my truck back together after the head gasket replacement, I cranked it w/ the nuts loose, made a *really* big mess. But after I tightened the nuts it fired right up. Then it was off to get the hose and clean up the mess.

 

[Paychk]

Next, the start/stop solenoid has two wires attached to it. One is black and, one blue.

One wire carries an initial "trigger" voltage that is 12 volts... this in turn activates the solenoid... then once the truck is at or over cranking voltage the second wire provides a maintainence voltage. . I believe it is stepped down to 10 VDC.

PB the FSM shows that the Black wire at the fuel solenoid is for power and the dark blue provides power from the fuel solenoid through a thermo switch to the KSB. So if the FSM is right the black should be 12 volts and the bark blue will be at some level below 12, cause the fuel cutoff is using some to stay open.

 

[dpuckett]

Bob, the solenoid will stay open at 3. 5 volts. Found that out when the alt locked up on my first one. Battery only had 3 or so volts, and would only hold 6V of charge. And, why does my pcikp run with only one wire (the blue one)? No black wire on my pickup.



Back to the subject at hand. Sounds like a fuel delivery problem. Start at the fuel filter, and crack open the 10mm bleeder screw at the top of the filter housing. Make sure fuel is getting there, no foaming or bubbles, as you crank. Then move to the injectors. Crack them about 1/4 to 1/3 turn- NO MORE- then make sure they spray fuel up a good ways (like 6-10 inches) when you crank it. Like bgilbert said, one injector at a time. If it just dribbles fuel at the injectors, you have a supply issue. If the spraying is uneven (say, #1 shoots up just fine, but #3 and 4 just dribble), it is most likely the pump. Good luck and keep us updated.



Daniel

 

[BCaldwell]

If you are going to crack the fuel lines and crank the engine over remember not to crank for long periods as this is hard on the starter contacts.



Good luck Bill

 

[1stgen4evr]

hard on the starter contacts

Unk. Since you have the manual transmission you can get a friend and use the chain drive starter to get it going after you have determined that there is a reliable fuel supply to the pump. That will save the contacts. Nothing will make it run till you have fuel at the injectors. Be carefull what you hook to on the towed and towing truck.



James

 

[Uncle Joe]

Thanks to all of you for responding... .

Isaw a blue wire to the pump and I checked that for power,gota look for the black wire,

The truck hasnt run for at least a year, someone was "working" on it and the claim was that it started about 6 month ago, I need this thing like a hole in the head but couldnt resist the price... ..... the truck's electrical system is in shambles (the fuse box is zip tied to the steering coulumn,figure that one out!)

Any way, I wont get to it till saturday when I can check more things out , will post a report then... ... thanks to everybody ... ... ... . Joe

 

[bgilbert]

Joe, I love those kind that havent been run for some time and someone couldn't get it running, sell for cheap, then I step in and buy it and get er running. A good factory service manual, a test light and meter, it shouldn't be too tough to get back to running like a champ. Or just pass it on to me, I love challenges!

 

[A Johnson]

First make sure your not sucking air, then I would start by removing #5 valve cover and crank, make sure the camshaft is actually moving the valves up and down,(more than 1 case of a broken camshaft) now jump 12 volts from the battery + post to the solenoid and crank. If still no go, remove the solenoid and take the plunger and spring out, put the solenoid coil back in and see if she starts. If it does 1 of 2 things going on, bum solenoid or pump is coming apart and the shavings had the solenoid plunger hanging shut. (this should be evident by little pieces of metal on the plunger when you remove it. ) Most pumps will dribble fuel out at the injectors even when the solenoid is shut off, you can prove this by removing the wires off the solenoid crank it and watch it pump fuel at the injectors. Sometimes these won't shut off by the key, this is a sign little metal shavings are holding the plunger open. You can allways shut this off, if it does start, by the manual shut down lever on the side of the pump. (It is a lever that is spring loaded and has no linkage hooked to it.



A Johnson

 

[Uncle Joe]

All right guys... . I have an update!

Finaly it stoped raining about 12..... So I got on it

There are 2 solonoids on the pump,one on the side and one in the back(However dicided to put it there should be killed),pulled both out and verified operation, the one on the side pushes and the one on the top pulls( note :is it suppose to be spring loaded?... its not but ..... )

checked fuel delivery... ... fine.

Now I only have a blue wire going to the solonoid on the side... . no wire is avalable for the other solonoid(note condition of electrical system in prior post)... ... anyway I jumped both to + with jumpers

Finaly I pulled #1 inj out ,hooked it back onto the hi press line and cranked (with the solonoids enerjized )... ... . no spray out of the injector!

compession seems just fine... .



Any further ways to test the pump?

what is the purpose of the horisontal spring loaded shaft on the pump thats secures to the throtle bracket with springs?

How to tell if the pump is turning without pulling the front cover?

If your wrists are killing you from typing (like mine) feel free to call me @ 940 206 9747... or you can pm me with a phone #

note ... . I have experiance working on the in line pump systems (mostly M/B)

but never had to mess with the rotarys... ... ... ... . Joe

 

[Paychk]

what is the purpose of the horisontal spring loaded shaft on the pump thats secures to the throtle bracket with springs?

Is this shaft sticking out of the side of the pump or top?



If it sticks out the side, that is the manual shut down valve and it should be spring loaded so the top of the linkage is to the firewall. If it is in any other position it will shut off the fuel flow, regardless of what the solenoid is doing.

 

[1stgen4evr]

without pulling the front cover?

Take the bolt out of the strut that holds the fill neck. That will allow you to turn the fill neck at the base and remove it from the front cover. You can see that the pump is turning or not by observing the gear there. I seriously doubt that is a factor.



My guess is that you don't have fuel to the pump and / or that you allowed a good bit of air into the system when you had the solonoids open. You can remove the plunger from the on off solonoid ( the one that is so hard to get to) and put it back together. You will have to kill the truck with the manual shut off lever that paychk pointed out. The solonoid on the side of the pump is to increase the fuel during starting for quicker start up. Mine has been unhooked for years and has no ill effect.



One thing I have done in the past is to hook up a douch bag arrangment to the fuel system so that I know I have fuel at the pump. That is, provide a bit of hydraulic head to the system rather than pulling from a low mounted tank. Do this with certainty that you are clean with everything. You could rig a small thumper pump that NAPA sells to be certain that you are pushing fuel to the pump.



You didnt have to pull the injector. Just open the line at the injector. I have found it useful to open all the fuel lines at the injectors a turn, so that there is no back pressure at all on the system, allowing (I think) quicker purging and startup for less battery drain and starter wear.



Pumps do go bad but if it hasn't been tinkered with, 250k is not indicative of a problem.



I recomend the chain drive starter.



1stgen4evr

James

 

[Uncle Joe]

Well guys I got an update... .

I did all that was recomended including removal of she shut off plunger, short of the chain drive start.

I cranked it over with all the line nuts cranked loose till fuel came out of all inj lines(at the injector)... ... no start yet

finaly I got tired of playing games with it , so I unhooked rhe #1 inj line from the injector , got a m/b 617 injector and hooked it to the line and cranked hoping fo a spray..... none happened!... ... at this point Im suspecting that the pump is not developing the press required to fire up the injector.

Can any one know how to prove or disprove my conclusion?

What we have here is fuel being delivered to the injectors but non will come out of the nozle... ... ..... Joe

 

[1stgen4evr]

prove or disprove my conclusion

If the M/B injector is similar or less as to pop pressure and is in fact good, and you have cranked enough to know the MB injector is fueling along with the others lines bleeding, I think you have proven already.



It also follows from evaluating your posts (and our phone conversation) that there was some reason the previous owner couldn't get the truck to run. The failure of the injection system is first manifest by low pressure and hard starting.



Before you pull the pump, unload the truck and tighten the lines. You know that the pump is primed and should make the engine run if it isn't worn out. Pull the truck at a sufficient speed to raise the operating pressure of the pump beyond what the starter can do. If it runs at all that way and doesn't clear up, pull the pump and off to a rebulid shop.



James

 

[BushWakr - RIP]

You just proved it uncle joe... . if you're not getting a good solid spray then your pump and or delivery valve(s) are pooched... sorry man...



pb