Hey guys, I have a 1996 Sub w/ 6.5TD. I've had some major problems with it recently: On start (winter) it would start fine, idle for about 3 mins, then die. I'd restart, it would work another 5 mins, then die again. After about 10 mins idling to warm up I take it on the road and it drives fine. This was LAST winter.


During the summer I decided that I didn't want a repeat of last year so I took it to my GM dealer's shop where they changed the fuel pump (warranty applied then) and the fuel filter. Truck still stalled on starting. Had major starting problems again and took it to the same shop again. They changed the ECM and the temperature sensor.


Guess what: Problem got WAY worse! http://dieselplace.com/forum/smileys/Angry.gif In addition to stalling on starting it would now start stalling on me on the highways going at 50+mph, 60+mph, 70+mph. Sometimes it would kick back up when I press the pedal but mostly it doesn't. Almost got rear ended several times!


The main problem with it not restarting again is that the glow plugs would NOT light up (the wait to start light) and the lift pump doesn't pump fuel when that happens. Sometimes I have to flick the ignition back and forth 50+ times until the glow plug light goes on for a split second and then the pump would work too and I could start it if lucky.


Help me out folks, what can I do and what could be the problem? I'm tired of dropping $600 at the dealer each time they want to "experiment" with my truck by changing things that are not causing the problem only to make it worse and cause me to risk my family's life each time we go someplace.


All suggestions welcome and appreciated!

could be either the Oil Pressure switch, that controls the lift pump or some guys have had problem with the ignition switch. I don't think either are very costly and I would change them both out. Edited by: 16gaSxS

16gaSxS, thanks for the reply. Unfortunately I don't think either of those components are to blame because the lift pump works well and the ignition switch shouldn't have anything to do with the stalling or no glow plugs. I mean, I can crank the engine when there are no glow plugs so the ignition switch is fine. It's just that the engine doesn't fire up for one reason or another.


Some of techs I spoke to said it could be a bad PMD but it doesn't really make sense to me: Why does it only cause problems in the winter (when it's cold) and not at all during the summer (when it's hot)? Why does it stall when the engine is cold but not as often when it's nice and warmed up?

L65 nonEGR?


The wastegate solenoid will make it stall if it's not working.but it usually comes with black exhaust when you accelerate.(The unboosted aircharge incompletely burns the fuel.)


L56 w/EGR?


Ok now it's three solenoids and an egr with vacuum lines in between.

L65 nonEGR?


The wastegate solenoid will make it stall if it's not working.but it usually comes with black exhaust when you accelerate.(The unboosted aircharge incompletely burns the fuel.)


L56 w/EGR?


Ok now it's three solenoids and an egr with vacuum lines in between.








Quantum, not really sure what you mean by L56 w/EGR or the other option. I'm guessing it's w/EGR since fuel pumps after 1994 have come with EGR. A question for my interest: Is the wastegait solenoid the little black thing with two hoses (red and black) coming into it? If that's the one then I did replace it just a few days ago because when I was trying to take the cover off it broke so I put in a new one.

Partial:


L56 is emissions engine, with egr valve on top center of upper intake manifold, and cataylitic converter. Normally only 1500 series trucks/burbs. L65 no cat and no EGR on most 2500/3500 series trucks. EGR should not do the things you are desribing, a problem in WG very well could be culprit. go to this post for a pic of the EGR http://dieselplace.com/forum/forum_posts.asp?TID=4842&KW


For your pump/filter replacement which pump lift or injection pump, if your lift pump is bad or you are having power problems with it that could be part of the problem as well, do a search on OPS and lift pump OPS can have bad contacts that cause intermittent problems. OPS is tied to lift pump,


Could be ignition switch also, intermittent fault there could be culprit; again search that topic or PMD on the side of the IP


Lets try 1 at a time, for lift pump start truck run at idle open drain valve from filter bowl, that is the brass valve sort of center front of engine standing at hood looking in, chrome tee handle open it if truck sarts to stumble there, maybe a problem with lift delivery.


As a 96 you should have a vac WG not spring loaded, so do a hand over hand of all vac lines, a vac leak could be a problem, if no leaks found check for main vac, should be min 22" go to your solenoid bank at drivers side of engine the line from pass side of engine at vac pump to 1st solenoid is main line that you need to check for vac. check those things and get back to us.


Also update your sig line which burb do you have, you might as well look up your RPO codes in the glove box sticker that will tell you lots about your buggies equipment. Do a RPO search I posted them some time back


Knowing that info like L56 or 65 helps us to try and figure out what to recommend next. Do you have a digital camera that you can send us a pic of what you broke.