Join Date: Mar 2007
Thanked 134 Times in 130 Posts
Pull them out and hook them to a 'pop stand' that will apply pressure to check for leaking, spray pattern and pop pressure.
My Isuzu pops at 1700psi and when 1500 psi is applied should not drip fuel but at + or - 5% should open the pintle and spray on an even pattern to the side.
Others spray cone and pressures vary with the brand and appliction.
With the voltages my next step would be the relay, if it is seperate from the controler. Or put a jumper in for 12 v to the glow plugs. The resistance readings are the same on all glow plugs - the do not normally fail as a set and any continuity is most often a working plug. Things change at about 20 F so if they are marginal and the temps go that low get the specs.
If you can see water, take a thin tube ( aquarium air hose works well) and put it in the water bubble and apply vacuum to the hose. Poking a couple of holes in a jar lid makes a catch container. Diesel is not recomended for beverage.
Black smoke when you bump the throttle on a non turbo is normal, black smoke when you load the engine at less than operating rpm is normal, it should start blowing smoke as it drops below the peak torque.
The failure to bump off on glow plug but to do a good job starting after first start has a pretty short list to look at. leaks that drop the fuel available at start, glow plugs and cranking rpm.
If you have compressed air you can disconnect the fuel return and clamp off to the tank and then put 3-4 pounds air pressure in the tank and see if the fuel comes out the return fitting instantly or sputters first. If the fuel system is liquid full the fuel from the return will be smooth, if it has air it will not be smooth and steady.
The little ones often have a lever on the side of the lift pump for priming. When I see 'crank 20 seconds and wait 6 min to prime' I see poor design that the Japanese are seldom guilty of. Middle size is often a plunger that looks like a cap or accumulator. Big ones have air.
The 12.5 is not a fully charged battery. 12.6 after setting a week and up to 13.6 after shut down, an hour later probably 13.2.
93 Dodge /CTD, IC, 518, club cab LE, BHAF, KDP fixed, kelderman air ride
81 Isuzu /C223na, 5spd