Please Help Running issues!
#1
02-11-2014, 03:45 PM
Please Help Running issues!
Hey peeps,
I am hoping that someone here can give me some assistance with my issue..
My truck is a 1994 GMC K2500 6.5L diesel VIN F 4x4
Truck has about 192K miles on it. About 6 months ago I swapped out the motor as the stock one blew up from lack of oil.. I installed a 1996 Chevy 6.5 with 201K in it. I swapped out the injector pump from my motor,the intake, the drivers side head and some other stuff.
When I first ran the motor is had somewhat of a skip to it, but was only noticeable if you revved it up in neutral.
A few months later I was pulling my bobcat up-hill in a snow storm and the thing started to pop and skip bad. Since then no matter what I have tried I cannot get the skip and lack of power to go away.
Truck seems to act up more when its under a load: like plowing or climbing a hill even if its empty. I don't notice the issue much on short local trips. It really gives me trouble during snow storms when I have her running for 12+ hours at a time.
Here is what I have done: Since issue started
8 new Injectors (Bosch)
AC delco lift pump
Fuel Filter (napa)
Crankcase Depression Breather (napa)
AC Delco crank Pos. sensor
Since I bought truck 1 year ago:
Remote mounted PMD (behind front bumper w/ heat sink) Grounded straight to battery
2 New batteries
Starter
Alternator
Airtex sending unit (in tank) Have AC Delco one that i plan to swap out..
8 AC delco Glow Plugs
a/c compressor
thermostat & Coolant
air filter
oil and filter changes
Oil pressure switch
coolant temp sensor
drivers Head gasket
Serp Belt
Diamond eye 4 inch turbo back exhaust (no muffler)
I am sure there are tons more things I can't think of off the top of my head right now
Any idea?
---AutoMerged DoublePost---
also wanted to add:
When the truck starts to really act up, it runs so bad that it wont really stay running! I pops and skips and puffs tons of white smoke. when you rev it in neutral you get black smoke which i think is kinda normal.
I am hoping that someone here can give me some assistance with my issue..
My truck is a 1994 GMC K2500 6.5L diesel VIN F 4x4
Truck has about 192K miles on it. About 6 months ago I swapped out the motor as the stock one blew up from lack of oil.. I installed a 1996 Chevy 6.5 with 201K in it. I swapped out the injector pump from my motor,the intake, the drivers side head and some other stuff.
When I first ran the motor is had somewhat of a skip to it, but was only noticeable if you revved it up in neutral.
A few months later I was pulling my bobcat up-hill in a snow storm and the thing started to pop and skip bad. Since then no matter what I have tried I cannot get the skip and lack of power to go away.
Truck seems to act up more when its under a load: like plowing or climbing a hill even if its empty. I don't notice the issue much on short local trips. It really gives me trouble during snow storms when I have her running for 12+ hours at a time.
Here is what I have done: Since issue started
8 new Injectors (Bosch)
AC delco lift pump
Fuel Filter (napa)
Crankcase Depression Breather (napa)
AC Delco crank Pos. sensor
Since I bought truck 1 year ago:
Remote mounted PMD (behind front bumper w/ heat sink) Grounded straight to battery
2 New batteries
Starter
Alternator
Airtex sending unit (in tank) Have AC Delco one that i plan to swap out..
8 AC delco Glow Plugs
a/c compressor
thermostat & Coolant
air filter
oil and filter changes
Oil pressure switch
coolant temp sensor
drivers Head gasket
Serp Belt
Diamond eye 4 inch turbo back exhaust (no muffler)
I am sure there are tons more things I can't think of off the top of my head right now
Any idea?
---AutoMerged DoublePost---
also wanted to add:
When the truck starts to really act up, it runs so bad that it wont really stay running! I pops and skips and puffs tons of white smoke. when you rev it in neutral you get black smoke which i think is kinda normal.
Last edited by Repomatt; 02-11-2014 at 03:45 PM. Reason: Automerged Doublepost
#2
02-11-2014, 04:20 PM
Diesel Enthusiast
#3
02-12-2014, 04:09 PM
Couple of things that I notice were not mentioned.
Did you buy a new PMD when you remote mounted it? Or the same one?
Have you checked for proper operation of the turbo and vacuum system?
Have you checked for computer codes?
When you replaced motor, did you perform the TDCO relearn?
Did you buy a new PMD when you remote mounted it? Or the same one?
Have you checked for proper operation of the turbo and vacuum system?
Have you checked for computer codes?
When you replaced motor, did you perform the TDCO relearn?
Yes the PMD was new when i relocated it.
Yes the turbo and vacuum are working fine.
There are no codes in the computer.
what is a TDCO relearn??
#4
02-13-2014, 03:44 PM
Diesel Enthusiast
Top Dead Center Offset. When the IP physical timing is reset, the TDCO relearn tells the computer the new timing offset, so that the computer adjusts correctly. Racer or someone more knowledgeable about the electronic IP can tell you more and use the correct terminology.
Search the forum for "TDCO" and you should find plenty of threads on how to do it.
Search the forum for "TDCO" and you should find plenty of threads on how to do it.
#6
02-17-2014, 09:09 AM
#7
02-17-2014, 10:10 AM
Diesel Enthusiast
That being the case, I would look at your fuel system very closely.
Run about 3/4 gallon out the T drain, Note the flow and look for crud.
Have you redone the fuel lines under the intake?
The sending unit could present an issue, I've heard the screen on the suction tube is not as good as the AC Delco's and blocks up easier.
I'm assuming you cleaned the tank when you changed the sending unit.
I'm also assuming you cleaned the bowl when you changed the fuel filter.
When changing the filter, I fill the bowl about 1/2 full of Sea Foam. Hot wire the lift pump, bleed the filter. Turn the key to run for about 15 minutes or so with the lift pump hot wired.
Turning the key to run should open the Fuel shut off solenoid and allow some of the Sea Foam to get in the Injection Pump.
Check all battery connections and cables. Check and clean all grounds, Add additional grounds, try a known to be good PMD. Even on a heat sink, PMD's can have a terribly short life span. They have even been known to be bad out of the box.
I also do the allen screw battery bolt upgrade. I use a 1 1/2" or 1 1/4" stainless allen screw in place of the battery cable bolts then washers and a nut.
The brass seals for your from brake lines work well - or any similar sized washer- I prefer brass, copper or stainless washers. I always save them and end up using them. I coat everything with Kopper-Kote - all connections to prevent corrosion in the future.
I remove the passenger side battery and add a ground to the battery box bolt, to the frame ground by the starter, to the PMD heat sink and to the stud at the back of the engine - by the firewall that has the really important grounds attached to it - I have seen these studs lose ground or have intermittent ground - many times.
I also add a ground from the heater blower to the dash bracket just inches away. Make sure the ground to the top of the Injection pump is there. I also run a ground wire from there to the ground cable from the battery close by. I use at least 10 ga black stranded wire for all the additional grounds with the exception of the ground on top of the IP. That I generally use 12 ga.
I like to solder my electrical connections.
If you redo the battery cables, do not use the cheesey clamp on battery cable ends. Get the solder on/crimp on style. I crimp them and then fill them with solder. I have recently had trouble finding this style of side post connector and ended up using heavy duty 3/8' eyelets instead. I need to find more of the appropriate connectors and order them.
On a 1994, you will want to do the dual lift pump relay upgrade. You can google for a schematic by Buddy. You can check my threads on dieselplace.com and the truckstop for when I did mine on my 1994.
Use an AC Delco lift pump for a 1993 - they have slightly higher flow - if replacing with an OEM style lift pump.
I'd do the ground and dual lift pump relay upgrades first.
What brand of PMD did you use? Every brand is hit and miss. I've had 3 short lived gray Standynes while others have had good longevity - so far from them.
I've heard bad reports on the Dorman made in China PMD's - angelofishes says that he has sold 140 plus of those with lifetime guarantees and no returns.
For now I am sticking with Flight Systems PMD's only.
Run about 3/4 gallon out the T drain, Note the flow and look for crud.
Have you redone the fuel lines under the intake?
The sending unit could present an issue, I've heard the screen on the suction tube is not as good as the AC Delco's and blocks up easier.
I'm assuming you cleaned the tank when you changed the sending unit.
I'm also assuming you cleaned the bowl when you changed the fuel filter.
When changing the filter, I fill the bowl about 1/2 full of Sea Foam. Hot wire the lift pump, bleed the filter. Turn the key to run for about 15 minutes or so with the lift pump hot wired.
Turning the key to run should open the Fuel shut off solenoid and allow some of the Sea Foam to get in the Injection Pump.
Check all battery connections and cables. Check and clean all grounds, Add additional grounds, try a known to be good PMD. Even on a heat sink, PMD's can have a terribly short life span. They have even been known to be bad out of the box.
I also do the allen screw battery bolt upgrade. I use a 1 1/2" or 1 1/4" stainless allen screw in place of the battery cable bolts then washers and a nut.
The brass seals for your from brake lines work well - or any similar sized washer- I prefer brass, copper or stainless washers. I always save them and end up using them. I coat everything with Kopper-Kote - all connections to prevent corrosion in the future.
I remove the passenger side battery and add a ground to the battery box bolt, to the frame ground by the starter, to the PMD heat sink and to the stud at the back of the engine - by the firewall that has the really important grounds attached to it - I have seen these studs lose ground or have intermittent ground - many times.
I also add a ground from the heater blower to the dash bracket just inches away. Make sure the ground to the top of the Injection pump is there. I also run a ground wire from there to the ground cable from the battery close by. I use at least 10 ga black stranded wire for all the additional grounds with the exception of the ground on top of the IP. That I generally use 12 ga.
I like to solder my electrical connections.
If you redo the battery cables, do not use the cheesey clamp on battery cable ends. Get the solder on/crimp on style. I crimp them and then fill them with solder. I have recently had trouble finding this style of side post connector and ended up using heavy duty 3/8' eyelets instead. I need to find more of the appropriate connectors and order them.
On a 1994, you will want to do the dual lift pump relay upgrade. You can google for a schematic by Buddy. You can check my threads on dieselplace.com and the truckstop for when I did mine on my 1994.
Use an AC Delco lift pump for a 1993 - they have slightly higher flow - if replacing with an OEM style lift pump.
I'd do the ground and dual lift pump relay upgrades first.
What brand of PMD did you use? Every brand is hit and miss. I've had 3 short lived gray Standynes while others have had good longevity - so far from them.
I've heard bad reports on the Dorman made in China PMD's - angelofishes says that he has sold 140 plus of those with lifetime guarantees and no returns.
For now I am sticking with Flight Systems PMD's only.
#8
02-17-2014, 04:08 PM
TDCO relearn can only be done with 1 of 3 scan tools on 94/95 trucks.
Tech 1,TechII with OBD1 expansion module or GMTD ScanTech pro version.
AC Delco ONLY for OPS.parts store OPS are often bad straight out of the box.
OPS relay mod mandatory for long term reliability.
I would also with the engine running,carfully crack each injector loose and then tighten 1 at a time and note what if any difference ther is in how the engine runs-don't get hurt or caught in moving parts!
A dead or weak cylinder could mean a bad injector or low compression and could help narrow down an issue with an affected cylinder.
Tech 1,TechII with OBD1 expansion module or GMTD ScanTech pro version.
AC Delco ONLY for OPS.parts store OPS are often bad straight out of the box.
OPS relay mod mandatory for long term reliability.
I would also with the engine running,carfully crack each injector loose and then tighten 1 at a time and note what if any difference ther is in how the engine runs-don't get hurt or caught in moving parts!
A dead or weak cylinder could mean a bad injector or low compression and could help narrow down an issue with an affected cylinder.
Last edited by racer55; 02-17-2014 at 04:11 PM.
#9
02-19-2014, 09:31 PM
TDCO relearn can only be done with 1 of 3 scan tools on 94/95 trucks.
Tech 1,TechII with OBD1 expansion module or GMTD ScanTech pro version.
AC Delco ONLY for OPS.parts store OPS are often bad straight out of the box.
OPS relay mod mandatory for long term reliability.
I would also with the engine running,carfully crack each injector loose and then tighten 1 at a time and note what if any difference ther is in how the engine runs-don't get hurt or caught in moving parts!
A dead or weak cylinder could mean a bad injector or low compression and could help narrow down an issue with an affected cylinder.
Tech 1,TechII with OBD1 expansion module or GMTD ScanTech pro version.
AC Delco ONLY for OPS.parts store OPS are often bad straight out of the box.
OPS relay mod mandatory for long term reliability.
I would also with the engine running,carfully crack each injector loose and then tighten 1 at a time and note what if any difference ther is in how the engine runs-don't get hurt or caught in moving parts!
A dead or weak cylinder could mean a bad injector or low compression and could help narrow down an issue with an affected cylinder.
I have replaced the sensors with AC Delco that have gone bad. I will not use NON-AC Delco stuff at all in the future.
Yes my buddy that is a tech for the US Army recommended the cracking of lines with the truck running but that is easier said than done as you cannot get to the pass side lines with the upper intake and turbo stuff connected.
I will have to do the compression check when i get a bit of time. Truck is just sitting collecting snow at this point.
---AutoMerged DoublePost---
That being the case, I would look at your fuel system very closely.
Run about 3/4 gallon out the T drain, Note the flow and look for crud.
Have you redone the fuel lines under the intake?
The sending unit could present an issue, I've heard the screen on the suction tube is not as good as the AC Delco's and blocks up easier.
I'm assuming you cleaned the tank when you changed the sending unit.
I'm also assuming you cleaned the bowl when you changed the fuel filter.
When changing the filter, I fill the bowl about 1/2 full of Sea Foam. Hot wire the lift pump, bleed the filter. Turn the key to run for about 15 minutes or so with the lift pump hot wired.
Turning the key to run should open the Fuel shut off solenoid and allow some of the Sea Foam to get in the Injection Pump.
Check all battery connections and cables. Check and clean all grounds, Add additional grounds, try a known to be good PMD. Even on a heat sink, PMD's can have a terribly short life span. They have even been known to be bad out of the box.
I also do the allen screw battery bolt upgrade. I use a 1 1/2" or 1 1/4" stainless allen screw in place of the battery cable bolts then washers and a nut.
The brass seals for your from brake lines work well - or any similar sized washer- I prefer brass, copper or stainless washers. I always save them and end up using them. I coat everything with Kopper-Kote - all connections to prevent corrosion in the future.
I remove the passenger side battery and add a ground to the battery box bolt, to the frame ground by the starter, to the PMD heat sink and to the stud at the back of the engine - by the firewall that has the really important grounds attached to it - I have seen these studs lose ground or have intermittent ground - many times.
I also add a ground from the heater blower to the dash bracket just inches away. Make sure the ground to the top of the Injection pump is there. I also run a ground wire from there to the ground cable from the battery close by. I use at least 10 ga black stranded wire for all the additional grounds with the exception of the ground on top of the IP. That I generally use 12 ga.
I like to solder my electrical connections.
If you redo the battery cables, do not use the cheesey clamp on battery cable ends. Get the solder on/crimp on style. I crimp them and then fill them with solder. I have recently had trouble finding this style of side post connector and ended up using heavy duty 3/8' eyelets instead. I need to find more of the appropriate connectors and order them.
On a 1994, you will want to do the dual lift pump relay upgrade. You can google for a schematic by Buddy. You can check my threads on dieselplace.com and the truckstop for when I did mine on my 1994.
Use an AC Delco lift pump for a 1993 - they have slightly higher flow - if replacing with an OEM style lift pump.
I'd do the ground and dual lift pump relay upgrades first.
What brand of PMD did you use? Every brand is hit and miss. I've had 3 short lived gray Standynes while others have had good longevity - so far from them.
I've heard bad reports on the Dorman made in China PMD's - angelofishes says that he has sold 140 plus of those with lifetime guarantees and no returns.
For now I am sticking with Flight Systems PMD's only.
Run about 3/4 gallon out the T drain, Note the flow and look for crud.
Have you redone the fuel lines under the intake?
The sending unit could present an issue, I've heard the screen on the suction tube is not as good as the AC Delco's and blocks up easier.
I'm assuming you cleaned the tank when you changed the sending unit.
I'm also assuming you cleaned the bowl when you changed the fuel filter.
When changing the filter, I fill the bowl about 1/2 full of Sea Foam. Hot wire the lift pump, bleed the filter. Turn the key to run for about 15 minutes or so with the lift pump hot wired.
Turning the key to run should open the Fuel shut off solenoid and allow some of the Sea Foam to get in the Injection Pump.
Check all battery connections and cables. Check and clean all grounds, Add additional grounds, try a known to be good PMD. Even on a heat sink, PMD's can have a terribly short life span. They have even been known to be bad out of the box.
I also do the allen screw battery bolt upgrade. I use a 1 1/2" or 1 1/4" stainless allen screw in place of the battery cable bolts then washers and a nut.
The brass seals for your from brake lines work well - or any similar sized washer- I prefer brass, copper or stainless washers. I always save them and end up using them. I coat everything with Kopper-Kote - all connections to prevent corrosion in the future.
I remove the passenger side battery and add a ground to the battery box bolt, to the frame ground by the starter, to the PMD heat sink and to the stud at the back of the engine - by the firewall that has the really important grounds attached to it - I have seen these studs lose ground or have intermittent ground - many times.
I also add a ground from the heater blower to the dash bracket just inches away. Make sure the ground to the top of the Injection pump is there. I also run a ground wire from there to the ground cable from the battery close by. I use at least 10 ga black stranded wire for all the additional grounds with the exception of the ground on top of the IP. That I generally use 12 ga.
I like to solder my electrical connections.
If you redo the battery cables, do not use the cheesey clamp on battery cable ends. Get the solder on/crimp on style. I crimp them and then fill them with solder. I have recently had trouble finding this style of side post connector and ended up using heavy duty 3/8' eyelets instead. I need to find more of the appropriate connectors and order them.
On a 1994, you will want to do the dual lift pump relay upgrade. You can google for a schematic by Buddy. You can check my threads on dieselplace.com and the truckstop for when I did mine on my 1994.
Use an AC Delco lift pump for a 1993 - they have slightly higher flow - if replacing with an OEM style lift pump.
I'd do the ground and dual lift pump relay upgrades first.
What brand of PMD did you use? Every brand is hit and miss. I've had 3 short lived gray Standynes while others have had good longevity - so far from them.
I've heard bad reports on the Dorman made in China PMD's - angelofishes says that he has sold 140 plus of those with lifetime guarantees and no returns.
For now I am sticking with Flight Systems PMD's only.
The Previous owner had replaced all the fuel line after the frame mounted pump to the filter housing with rubber house. What do you think of that? Do you know if there are replacement steel lines available anywhere? Far as I know there are no leaks anywhere as I have checked a few times.
I am not sure if I changed the lines under the intake, I pretty sure that I reused the lines when I swapped the motor. Should I change them?
Yea the sending unit is only about a year old, I plan to swap that AC Delco unit is as soon as I have time. Been snowing like crazy here haven’t had much time to mess with the truck. I did not clean the tank as it’s fairly new. I did look inside was nothing noticeable so I just installed new unit.
Yes when I change the filter I drain and wipe out the bowl and then I also fill it up with sea foam. I have a switch under the dash that I wired in to jump out the lift pump just in case.
The battery connections and grounds are deff good as I have an OCD with dirty battery connections. I have brass adapter on the batteries that are used to add accessories in the aftermarket world. I have tons of them from FISHER as they come with all new snow plows.
The PMD is a stanadyne brand. I was thinking that it may be part of my issue but they are $3-400 bucks and that’s a bit steep to just fire up the parts cannon in my book…. What brand do you recommend? The PMD is grounded direct to the battery. I did add a few in rear of motor but I will add more this weekend!
Hmmm I know that the ground on the top of the injector pump is off ill have to to take care of that!
I have never heard of the dual lift pump relay… I will have to do some research on that and figure out how to do it…
I was thinking of removing the lift pump yet again and installing this one:
Fuel Delivery
What do you think?
Thanks again for your input! I am ready to pull my hair out this truck is kicking my a$$!!
Last edited by Repomatt; 02-19-2014 at 09:31 PM. Reason: Automerged Doublepost
#10
02-20-2014, 09:47 AM
For a 94 GMTD ScanTech Pro version is a great laptop program and is the ONLY laptop program that can do TDCO relearn-it is money well spent for the license and cable if you intend to keep the truck for a good while yet,it is OBD1 ONLY though,great for your truck but little else.
PMD's have become much mor reasonable as of late,about $130 with lifetime warranty from Amazon,they also have heatsinks,extension harnesses and resistors available.
The brand is dorman but since they are all poor brand does not seem to matter anymore-warranty does.
Nothing wrong with rubber fuel line after the LP if it is not reacting with any chemicals in the diesel.
PMD's have become much mor reasonable as of late,about $130 with lifetime warranty from Amazon,they also have heatsinks,extension harnesses and resistors available.
The brand is dorman but since they are all poor brand does not seem to matter anymore-warranty does.
Nothing wrong with rubber fuel line after the LP if it is not reacting with any chemicals in the diesel.
Last edited by racer55; 02-20-2014 at 09:50 AM.
