1996 6.5td

[Irish_Alley]

so we picked up a 1996 ¾ ton ext cab 4x4 for $600 we knew the truck used to be a plow truck so we expected it to be all rotten out. the P.O. parked it 2 years ago (think he got a new truck) and its been sitting at his dads place since. plans where to rip the motor out and put in a 88 3+3 this would be my company truck. but then we saw the truck and for its history we both where shocked at how good it looked and might just keep her this way. but anyway to the question.
so upon putting 2 batteries in her we tried the key. no click or clicking or anything, so we double checked the battery cables. all is good still nothing. then we test the signal wire to the starter its getting power, and we'er able to jump the starter and turn over the engine. (so bad starter for one)
it seamed like for ever then she finally fired up. real high rpms dont know for sure but it seamed like 2k then she would drop to 1k then back up to 2k it wouldnt stop surging and with the surges would be white smoke then black smoke. dont really know where to start with diesels and im looking online for possible ideals. anyone have a clue? my buddy wanted to replaced the fuel pump just because we had another just laying around, it didnt help. next on his list is the "black box" (PMD)its already been remounted from the Ip to the fender. dont think thats the problem but i dont know anything about these things. also during this brief time we had her surging the gas pedal wouldn't effect anything leads me to the accelerator pedal sensor thingy(apps)?. on a gas motor i think we would call it tps

[Irish_Alley]

another thing (i didnt see it but my buddy saw it) the glow plugs seamed to been damaged at one point and are bypassed?

[Irish_Alley]

ok found this

"The PMD (pump mounted driver) is that small black box mounted on the side of your injection pump. It is a signal amplifier that powers the fuel solenoid. It contains 2-500 watt transistors which create a lot of heat. The factory mistakenly mounted this PMD module on the side of an already hot injection pump and in the engine valley below the intake manifold where temperatures skyrocket. As everyone knows, electronics do not like heat and they will fail prematurely. Symptoms of failure are stalling, hard starting, surging, poor fuel mileage, erratic idle and finally no-start. When they go it usually will not give any codes with the SES (Service Engine Soon) light. This American Made Cooler kit, relocates the PMD to a cooler area of the engine compartment, above the intake, on a massive oversized heat sink. A proven design. Our design has some distinct advantages over all the competition\'s. Please check our "advantages" section on our homepage and our FAQ section for details."
http://www.ssdieselsupply.com/p6_gm_6.5_diesel_fsd_heat_sync_kit_includes_pmd_and_resistor.html

now we already have a relocation kit installed, so im thinking we need to find a used but good pmd to test


Edit: remembering things as i go. when we first tried to start the truck we didnt hear the fuel pump. opened the bleeder on the rear of the motor and no fuel. i think he tested the fuel pump signal but he said there wasnt any power to it and he tried to jump it with his tester but couldnt even get it to power up then. so when we hooked up the other fuel pump we bypassed everything and ran a wire directly to the battery and still same deal as before with the surging idle and smoke.

[fitz]

My limited diesel experience comes from playing around with the CUCV Military pick ups with the 6.2 but the info should be the same on the 6.5 TD.
You have to get the glow plugs working.  You should be able to run them off a push button switch to bypass the factory system.
Did you bleed the fuel system after you replaced the fuel pump? I know on the 6.2's whenever you get any air in the fuel lines (like when changing fuel filters or pumps) you have to bleed the system to get them started. Sometimes they will fire over with some air in the system but they will surge and smoke till the air works its way out.

[Powerdriver1958]

X2 on the air in the fuel system . Diesels will surge and rev high when air is present . Eyeball the lines for any fuel stains . After sitting for so long I am happy it fired up . Most times you have to bleed the air from the very beginning .

[Displaced_Txn]

definitely would need to bleed the air out of the system after changing pumps. Did you also replace the fuel filter and drain the diesel out of the tanks? I'd also rig a bypass up to the glow plugs that way it will be easier to start when the engine is cold and in colder weather. The tps will be called the same on a diesel motor unless it is actually attached to the pedal then it would be called a apps so you were correct on that. normally they dont completely fail all the way normally just in one certain area, think of a fuel level sender same idea it can get worn out in one area and work in the other areas. Not sure on what the specs should be on it but if you can get the specs on what the voltage readings should be you can test them with an digital mulimeter.

[Irish_Alley]

never got around to testing the apps. but did put a new starter in her and the lift pump is now getting power and engine is turning over faster than before when we had her started. but my buddy noticed the pmd box wasnt getting hot unplugged it and she was melted. got a new one with a new lead now the new one aint getting hot. so were lost now dont know where to start looking. all fuses look good. the fuel solenoid clicks when the ignition is turned on and gets warm, dont know if thats good. but thats something we noticed

[Irish_Alley]

ok so i got a check list from a diesel page. and started to do the check list for the pmd . tested the new pmd all went good till the last step between "B" and "F" supposed to get a ac reading of .8-1.0 we got .2. just for craps and giggles I put the old melted pmd box in just to see what she was reading. very first rotation of the crank she wanted to fire up. so we got her started and she went back to the surging idle she will go to 900 with a touch of white/gray smoke then up to 2k with black smoke. so we might try to borrow someone's pmd and see what she does then.

 but before calling about receiving a bad pmd I put the new one back in to try and test the f and b post. Well she started up and idled at 800-900 rpms still smoked a little but it was more gray. Went to see if she will rev up, it went to 1k and wouldn't go any higher would start to miss and blow more smoke. Shut it off and restarted it only to have her idle at 400. But on my tester I wasn't getting any reading while cranking (B&F)