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1994 Chevy K3500 6.5 diesel 4x4

found fuel filter leaking, could this be letting air in fuel line? Would filter leaking cause truck to lose power while pulling 27 foot camper? Everything seems to be working will have to change coolant temp. sensor cause plug is broke and wires not tight on sensor. Small crack in wastegate vacuum line temporarely taped line with heat tape. Had to order vacuum lines waiting for them to come in. PMD is new and properly remote mounted with ground. Bolted to drivers fender under hood near battery, maybe should move to grill for more cool air. Thanks
 
First, solve your problems - Fuel filter leak is important - almost all of those codes will come from that. A bad optic sensor code in an OBD-I will almost certainly cascade into others. Buddy is right about your OS filter, also - it wouldn't hurt to get rid of it, either.

Leaking WG vacuum line is a biggie, as far as power goes when towing. That code 78 is caused by your engine not getting the boost the computer is calling for. Seriously, you need a chip and a turbomaster, at some point - you won't believe the difference when pulling.

We can help you a LOT with the necessary power and reliability mods for your truck - we've been there and done that, pulling big loads with the 6.5TD. That there is a good rig which should serve you very well.

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By the way - welcome to The Truck Stop!! As you noticed, this is a great place, full of great people who carry the best knowledge base on 6.5s you can find online. Take a read through our online reference library to learn more about your 6.5!

Take a minute to fill in your signature so we know more about your truck, and copy/paste/fill out the Diagnostic checklist so we can see/hear your truck through your eyes... it'll save lots of time in diagnosis, rather than asking and answering all these questions from us :)

Nice to meet ya!
Jim
 
I would for sure get the remote mounted pmd out of that location and mount it just behind or under the center of the bumper. You could be doing the pmd more harm now where you have it located rather than leaving on the pump. I would get it out of the engine compartment. I think you said the pmd is grounded at the heat sink? From what I understand the ground needs to stay with the IP.

Buddy and Acesneights have helped me out lots. I find them to be very very knowledgable.
 
your problem in concise language (ie: Cranks but won’t fire). ____________________________

Demographics: tell us about your truck and your ambient conditions:

- Year: 1994______
- Truck model and class (ie: c2500) _k3500________
- Automatic or Standard __auto________
- Mileage: (indicate miles or km) 171 thou_________
- Replaced parts and mods (IP, PMD, chip/PCM, TM, injectors etc) _new pmd ,injectors and glowplugs__________
- Model: ‘S’ or ‘F’ engine, NA or Turbo, EGR? F turbo______________
- Ambient outside temp: (indicate *C or *F) __________
- What fuel are you using? (#1 Diesel, #2 Diesel, Bio, VO, WVO, etc) _#1 diesel________
- What fuel additives are you using? __none_________
- Where are you located? _Georgia____________

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter __new_______
- Fuel filter _old________
- CDR Valve? __?_______
- Coolant – last flushed/replaced at _07-08-10____________
- Oil – synthetic/regular, changed at _07-01-10__________
- Batteries – state of charge, (matched set) replaced at _06-25-09____________
- Battery cables and grounds (removed, cleaned and tightened): _07-02-10_____________
- Glow Plugs - how many miles on them? _7000________ What type? __?___________
- Injectors - last changed at _7000 miles ago______________


History: (Describe how the problem first appeared.)
- What were you doing when it happened? _towing 27 ft camper_____________
- How was the truck running fine before this problem appeared? _fine____________
- Has this problem ever happened before? __no_____________________
- Describe any related factors that might be part of the problem. _fuel filter leaking_____________
- Have you checked for DTC (Diagnostic Trouble Codes)? (Y.N) _Y___ And? 15 18 35 49 78 85 87________


Diagnostics:

1] Starting:
1a] Does the engine start? __Y_______
1b] Does the engine crank over? __Y______
1c] Are your batteries fully charged? _Y________
1d] Have you removed, cleaned, and tightened all battery connections? _Y_______
1e] Does your Wait to Start light come on for a time? How long? _Y 4-5 sec________
1f] Does your glow plug light come on? _Y________ For how long? __4-5 sec_______
1g] Do you see smoke from the exhaust while cranking? What color? N________
1h] Does the Service Engine Light Glow during Start/bulb check? Y________

2] Fuel Issues (if not running):
2a] Can you hear your lift pump working? __Y__________
2b] Do you get a steady flow of fuel from the water drain (T-handle) ? __Y_______
2c] Loosen the inlet line from the IP – is fuel coming out (Lift Pump on)? _Y__________
2d] Loosen an injector line and crank the engine - does fuel come out? __Y_______
2e] Do you hear a vacuum (hiss) when you remove the fuel cap? __Y_________

3] PMD / IP Issues
3a] Location of PMD (on pump, on intake, remote mounted) _remote on driver fender__________
3b] Condition of Extension harness (if used) Vendor or Homemade? _new homemade________
3c] Condition of grounds / ground wires to IP / PMD. Check Harness. _good________
3d] PMD Make: _styn__________
3e] PMD Age: _07-11-10____________

4] Stalling Issues
4a] Do you experience stalling only when hot? ____no stalling________
4b] Does it stall under particular circumstances? (ie hit bump, or on accel) _no_____
4c] Does pouring cool water over the IP seem to help with restarting? not done_________
4d] Is stalling momentary (engine recovers)? _________
4e] Does SES light come on when engine hiccups? __no _______
4f] Does cruise control quit working when engine hiccups? _doesnt work anytime__________
4g] Does re-starting seem to reset engine, restoring cruise and power? __no_______
4h] Changes to dash lights or instruments during stalling events? ___no________

5] Running Issues
5a] On cold start, does upper rad hose get hard before engine warms up? __no_____
5b] Any bubbles or oil film in coolant overflow tank? _no______
5c] Any white slime on oil surfaces (dipstick, CDR, oil Fill cap)? __no________
5d] Excessive white smoke from exhaust on cold start? no_________
5e] Excessive black smoke from exhaust under hard acceleration? _no_________

6] Performance Issues
6a] Do you have gauges (boost, EGT) ? __no_________
6b] Maximum boost under load? ___?_________
6c] Have you added a performance PCM (reflash) or Chip? _new chip in new PMD_____________
6d] Have you changed exhaust / downpipe / crossover? ____no____________
6e] Wastegate – mechanical or vacuum (OEM)? __vacuum____________

7] Temperature-related Issues:
7a] Single or dual thermostats? __single__________
7b] Have you replaced them lately? Manufacturer of replacements? _Y Advance Auto ?________
7c] Have you pulled and cleaned Radiator and coolers lately? _new radiator on 07-11-10___________
7d] Have you replaced the fan clutch? Manufacturer of replacement? ___no_____
7e] (winter) Have you tested your antifreeze? Good to what temp? 07-11-10 -34 degrees__________
7f] (winter) Are you using a winter grille cover? _no__________

List and describe any other factors which are not addressed in this checklist. We can’t see, hear, smell, or touch your truck, so the more descriptive information you can give, the more likely it is that somebody can assist
 
your problem in concise language (ie: Cranks but won’t fire). ____________________________

Demographics: tell us about your truck and your ambient conditions:

- Year: 1994______
- Truck model and class (ie: c2500) _k3500_Chevy 6.5 turbo_______
- Automatic or Standard __auto________
- Mileage: (indicate miles or km) 171 thou_________
- Replaced parts and mods (IP, PMD, chip/PCM, TM, injectors etc) _new pmd ,injectors and glowplugs__________
- Model: ‘S’ or ‘F’ engine, NA or Turbo, EGR? F turbo______________
- Ambient outside temp: (indicate *C or *F) __________
- What fuel are you using? (#1 Diesel, #2 Diesel, Bio, VO, WVO, etc) _#1 diesel________
- What fuel additives are you using? __none_________
- Where are you located? _Georgia____________

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter __new_______
- Fuel filter _old________
- CDR Valve? __?_______
- Coolant – last flushed/replaced at _07-02-10____________
- Oil – synthetic/regular, changed at _06-25-10__________
- Batteries – state of charge, (matched set) replaced at _06-25-09____________
- Battery cables and grounds (removed, cleaned and tightened): _07-02-10_____________
- Glow Plugs - how many miles on them? _7000________ What type? __?___________
- Injectors - last changed at _7000 miles ago______________


History: (Describe how the problem first appeared.)
- What were you doing when it happened? _towing 27 ft camper_____________
- How was the truck running fine before this problem appeared? _fine____________
- Has this problem ever happened before? __no_____________________
- Describe any related factors that might be part of the problem. _fuel filter leaking_____________
- Have you checked for DTC (Diagnostic Trouble Codes)? (Y.N) _Y___ And? 15 18 35 49 78 85 87________


Diagnostics:

1] Starting:
1a] Does the engine start? __Y_______
1b] Does the engine crank over? __Y______
1c] Are your batteries fully charged? _Y________
1d] Have you removed, cleaned, and tightened all battery connections? _Y_______
1e] Does your Wait to Start light come on for a time? How long? _Y 4-5 sec________
1f] Does your glow plug light come on? _Y________ For how long? __4-5 sec_______
1g] Do you see smoke from the exhaust while cranking? What color__Y Grey______
1h] Does the Service Engine Light Glow during Start/bulb check? Y________

2] Fuel Issues (if not running):
2a] Can you hear your lift pump working? __Y__________
2b] Do you get a steady flow of fuel from the water drain (T-handle) ? __Y_______
2c] Loosen the inlet line from the IP – is fuel coming out (Lift Pump on)? _Y__________
2d] Loosen an injector line and crank the engine - does fuel come out? __Y_______
2e] Do you hear a vacuum (hiss) when you remove the fuel cap? __Y_________

3] PMD / IP Issues
3a] Location of PMD (on pump, on intake, remote mounted) _remote on driver fender__________
3b] Condition of Extension harness (if used) Vendor or Homemade? _new homemade________
3c] Condition of grounds / ground wires to IP / PMD. Check Harness. _good________
3d] PMD Make: _styn__________
3e] PMD Age: _07-02-10____________

4] Stalling Issues
4a] Do you experience stalling only when hot? ____no stalling________
4b] Does it stall under particular circumstances? (ie hit bump, or on accel) _no_____
4c] Does pouring cool water over the IP seem to help with restarting? not done_________
4d] Is stalling momentary (engine recovers)? _________
4e] Does SES light come on when engine hiccups? __no _______
4f] Does cruise control quit working when engine hiccups? _doesnt work anytime__________
4g] Does re-starting seem to reset engine, restoring cruise and power? __no_______
4h] Changes to dash lights or instruments during stalling events? ___no________

5] Running Issues
5a] On cold start, does upper rad hose get hard before engine warms up? __no_____
5b] Any bubbles or oil film in coolant overflow tank? _no______
5c] Any white slime on oil surfaces (dipstick, CDR, oil Fill cap)? __no________
5d] Excessive white smoke from exhaust on cold start? no__just small puff of grey_______
5e] Excessive black smoke from exhaust under hard acceleration? _no_________

6] Performance Issues
6a] Do you have gauges (boost, EGT) ? __no_________
6b] Maximum boost under load? ___?_________
6c] Have you added a performance PCM (reflash) or Chip? _new chip in new PMD_____________
6d] Have you changed exhaust / downpipe / crossover? ____no____________
6e] Wastegate – mechanical or vacuum (OEM)? __vacuum____________

7] Temperature-related Issues:
7a] Single or dual thermostats? __single__________
7b] Have you replaced them lately? Manufacturer of replacements? _Y Parts Master________
7c] Have you pulled and cleaned Radiator and coolers lately? _new radiator on 07-11-10___________
7d] Have you replaced the fan clutch? Manufacturer of replacement? ___no_____
7e] (winter) Have you tested your antifreeze? Good to what temp? 07-11-10 -34 degrees__________
7f] (winter) Are you using a winter grille cover? _no__________

List and describe any other factors which are not addressed in this checklist. We can’t see, hear, smell, or touch your truck, so the more descriptive information you can give, the more likely it is that somebody can assist
 
The loose filter will cause a lot of weird codes. So with that resolved run the stuff again. Most likely causing your 18 and maybe some sympathy codes.
 
bk95td said:
Where did the extension harness come from? Are all the wires in the extension harness black?
Click to expand...



Not to hijack, but the OP didnt answer either way...........

This scares me a little. I just replaced my extension cable (that had all blue wires in it, but was looking a bit frayed) with a new one, with all black wires in it.......................did I do bad?
 
Yachtcare said:
did I do bad?
Click to expand...
Nope... but it really does depend on where you got it. Some of the real cheap cables you can get on ebay aren't crimped properly, and the connectors are made of the wrong stuff... they can cause you more problems. If you bought a good harness, or extended it yourself, then you done fine.

Wire colour isn't really important, as long as nobody mixed 'em up :D

If you got it from Pensacola, it's probably fine.
 
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Thought fuel filter was leaking, it was main line from lift pump to fuel filter busted under clamp. Cut off inch and put line back on. Checked filter and clean as new also bowl clean. Bled air out of fuel filter and line. Cleared codes and drove truck. Checked codes and now have only three, 18, 35, and 49. Trans. shifting fine and oil pressure between 45 and 55. Lots more power. No wastegate or trans. codes but need to fix problem with these current codes. Dont think oil switch bad must be lift pump weak. Any suggestions? Moved PMD from drivers fender and mounted inside bumper where fog lights mount. Dont have fog lights just empty slots where they go. Should be real cool mounted there. Thanks...
 
Last edited:
fyi those aren't fog light holes unless there in the plastic air dam under the bumper. Those are extra cooling holes to bring more air to the cooling stack
 
ak diesel driver said:
fyi those aren't fog light holes unless there in the plastic air dam under the bumper. Those are extra cooling holes to bring more air to the cooling stack
Click to expand...

Shhhhh...That's a secret of the 6.5TD community...Now he knows. Forever cursed when he see's a truck go by with holes in the bumper, he will know it's a 6.5TD
 
You should check for the Optical Sensor Filter. If its there remove it. And then clear codes and run it.

It looks like this and will be plugged into the top of the IP. You want to remove it and then connect the engine harness straight to the top of the IP.
OS_harness_filter.jpg
 
DTC 18 - Pump Cam Reference Pulse Error
DTC 35 - Injection Pulse Width Error (Time Short)
DTC 49 - Service Throttle Soon Lamp Circuit Fault

Hmmm... you need to check the bulb in your STS light. The other two are common 'cascade' codes... they tend to show up when something else is whacked.

Thoughts:

1] Have you tried removing your OS filter, yet? It's a 4-wire (short) harness located off the top of your IP. If you can get at it, take it apart, remove the filter harness and plug it back together without it.

2] What do you run as a lubricity additive in your fuel? ULSD tends to make old IPs act up without it. I started putting a litre (quart) of 30wt motor oil (the cheap walmart stuff) in every tank and my codes 18 and 35 went away. Forever.
 
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