STALLING 6.5

[jimmie]

hello everyone.about 3 months back i bought a used 96 model 3500,with a 6.5 and a 5spd.the owner said the truck was low on power and hard to start.well i buy the truck and expect to drop some coin on a new pump.after checking for bad fuel,leaks and lift pump probs,fuel filter with no found problems,i invest in a pmd driver off ebay[little black box],trying this changes nothing.i buy a rebuilt inj pump with pmd off ebay.install and drive approx 50 miles before i take to dealer to get it timed.in the 50 miles that i drive the vehicle,it performs without a problem.[note,the truck is a little hard to start,wether hot or cold].after takeing the truck to the dealer for timeing,my problem begins.before leaving the dealer i check to make sure its cranking as should,which it does.less than two miles from the dealer the truck stalls,is hard to crank,when it does crank it misses and blows blue smoke really bad.turn around and go back to the dealer for help,they tell me i must have gotten a bad pump, to bad.drive 25 miles home,truck stays running at every stop light but runs bad,smokes and loses power.once i get to highway speed,it has normal power and the smoke all but quits.approx halfway home my brandnew altenator also quits working,tach quits working and the battery light comes on.drive approx two miles,it all starts working again for a few miles,then quits again permanatley.[previous altenator did this same routine].now for the kicker,i get home and let the truck set for about 2 hrs,truck will then crank and drive like it has no problem,untill the coolant temp gets near the normal mark[runs flawlessly for approx 6 to 8 min before symtoms start].let it sit over night and i get the same results.tried changing out the black box but this made no difference.all battery connections are clean and tight also. does anyone have a clue as to what might be wrong with this thing? i'am takeing it to a mechanic to get codes read on monday,but this guy is not a diesel mechanic,so other than having the code info ,i doubt he can help me. is there something that the dealer who timed it could have done to create a problem? i have had no trouble fixing my pre computer 6.5 or my 6.2 trucks,but this thing is eating me alive!! thanks for any input....

[Hubert]

I would check battery connections again and all grounds. Add some more to be safe. Passenger side I run a second to the back of head where other grounds connect.

Check wiring connections at PMD/FSD and all else you see.

Get codes and post back info.

[Bnave95]

after takeing the truck to the dealer for timeing


I'll bet they did not do the TDCO (top dead center offset) right.
A learn setting with the Tech II.
When you replaced the pump it still had the TDCO set as with the old pump. The new pump may have only been off on crank Deg. that would not effect the running to much.
I'd go back and ask at what TDCO learn did they go with.
Most of us are running a TDCO of -1.95.
This learn is tricky and can only hope the dealer Mech. knew what he was doing. :eek:

[twaddle]

I would second that one on the dealer not setting the timing properly.
Don't think the tech knows what he is doing, perhaps their diesel guy on holiday that day?

Is this a GM dealer and are they ok to talk to or are you going to have to look elsewhere?

Good luck

Jim Twaddle
Biggar, Scotland

[jimmie]

thanks for the quick replys,like i said this is really frustrating. i bought this truck as a standby.my old 6.2 was stolen and finaly a month later recovered,with some body damage and some other stuff wrong.need this 6.5 to work out of while i'am restoring the 6.2. the dealer i dealt with was a gm dealer thats been around for aleast 25 years that i know.they have been one of the few dealers that would even carry 6.5 trucks on the lots.before taking them the truck,i called and ask if they had a mechanic thats familar with the computerised 6.5,service man said they had two.maybe i need to go back and reread the diesel page clip on surviveing at trip to the mechanic! acording to the invoice,timing was set at 3.5. does this mean anything good or bad? as mentioned i will add another ground strap,and reclean my connections.the truck shows 98k on the odo,but the previous owner said the spedo quit a couple months before parking,wonder if gm would honor extended warranty? i will also ask about the tdco,anymore thoughts,keep them coming.just seems strang everything was fine untill i left the dealer.i have gotten a bad 6.2 pump before,[2 in a row]but they both showed problems as soon as i cranked the truck,not after nearly 50 miles of driveing like this one..

[Mark Rinker]

Don't forget to check all your fuse connections. One of my '94s has loose fuse connections and it mimicks a bad FSD.

The most likely culprit for what you describe is a 25-amp fuse labeled 'FSOL'.

[jimmie]

thanks mark,i have checked the fuses to see if all were working.but i havent checked them for a poor contact connection,will do.proably be wise to pull all of them and chk for corrosion,might get some contact cleaner also..ideas and past experiences of others are sometimes what gets a problem solved.thanks everyone,keep them coming!!

[twaddle]

Jimmie,
I would recommend using the contact cleaner on just about all the fuse and relay pins located at the fuse/relay box on the drivers side fender.

I had a intermittant No glow plug light fault for a while although it usually only showed up when the weather was below freezing point. since then I haven't had any problems with the glow plug light, touch wood quickly as I say that.

Regards and good luck,

Jim Twaddle
Biggar, Scotland

[jimmie]

will do jim.had to work yesterday,and the weather was cold with constant rain today.going to get the codes read tommorrow i hope,i will get the contact cleaner and start pullin fuses regardless.

[Bnave95]

Then after the cleaning,use some dielectric grease.

[jimmie]

well,as expected we had a small ice storm move in and the roads are in semi poor condition,not to mention the trailer is coated with about a 1/4 in sheet of ice.wont be able to load the truck and haul it to town,but i will do the fuse cleaning procedure and reclean all the battery connections.sure would be nice if that solved my issues.