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Hey Guys, This is my first diesel engine and I've spent the last 3 days trying to figure this out the main cause with the use of a service manual and some internet information and stumbled upon this site. Today, I am taking a different approach and see if I get somewhere. I've read the "FAQ for newbees" and have posted the diagnostic checklist below:

I will say that this is the most methodical approach and I'am glad there is a website like this.


The Diagnostic Checklist:
Please fill out to best of your knowledge.

1. Describe the problem you are having in detail:

Bus will crank but won't start. First off when I bought the bus it was stuck on 2nd (and reverse) but wouldn't shift to higher 3,4th gear. Thinking it was due to low voltage or something electrical I had the batteries checked to eliminate that issue and replaced the one under the hood but not the second one since it was showing 13V. I installed it and it started fine. I checked the OBD1 scanner and it was not communicating with my ECM so I tried a couple of times again. I then noticed the the "WTS" wait to start light was not illuminating anymore and when I tried to start it again it would just crank and not start like it always did. Checked all the fuses and they were all good. I checked the fuel supply and it was getting fuel up the the fuel filter management and "t" handle drain but when I loosen the injection line at the injector It doesn't get any fuel when I crank it over. I also noticed that it was leaking fuel under the FFM due to a worn o-ring seal. It also sat for a month but started first click when I got back so I probably have to change diesel soon.

2. Year of truck/engine. 1995 Chevy G30 Detroit diesel 6.4 V8
3. Odometer reading (indicate miles or kilometers). 345k miles
4. Indicate the model number on the Injection pump (starts DS4 or DB2......). Will check.
5. Indicate if you know if it’s a 1500, 2500, 2500HD, 3500, 3500HD. Don't know
6. Do you have an EGR on the engine? (An F or an S engine code 8th VIN digit) "Y"
7. Air Filter condition (visual check). Cleaned it
8. Fuel filter condition (freshly changed, mileage since changed). Don't know exact age but looks good.
9. Location of PMD/FSD? (ex. on pump/remote over intake, behind bumper). Will look for it.
9a. If remote mounted, describe wiring harness (homemade or purchased from which vendor). TBD
9b. Indicate the location and condition of the FSD/IP grounding wire. TBD
10. Outside Temperature (C or F). __65F___ °

11. Service Engine Light while running?- on/off/intermittent ON
11a. Service Engine light does glow during start/cranking/bulb check: Yes
12.Have you scanned for engine codes? Yes
12a. List exact results on engine codes. Didn't get any

13. Condition of Battery terminals (removed, cleaned and tightened). Clean and new
14. Known condition and age of Batteries. 1 is less than 4 and the other is new
14a. Are batteries a matched set of same age? No
15. Condition of Major Grounds (removed, cleaned and tightened) cleaned and tight.
15a Have the batteries been individually load tested? Yes

16. Does engine crank, or "turn over"? Yes
16a. Does engine start and run? no
17. If engine does not start- Crack injector line: do you have fuel? No
18. Does your Wait To Start light come on? No
18a.Number of seconds WTS light is lit. N/A
19. Engine Cranking speed (if you have an accurate tachometer). No accurate figure but cranks very strong.

20. Are you experiencing Stalling? N/A and didn't stall when it was running
20a. Describe the event (upon startup only, down the road, hit a bump, etc...)
20b. Do you notice loss of dash or instruments? Instrument cluster lights went off
21. Check turbo inlet and air filter for obstructions.N/A
22. In a no-hot start, pour a bottle of room-temp water on the injection pump. Does it start now? N/A
23. Lift pump test - Describe results. Working Fine

24. Upon cold start, does the radiator hose get hard quickly? No
25. Upon cold start, do you have excessive white smoke? Yes
26. Do you have excessive cranking time before the engine starts? N/A
27. Have you used the block heater? Does it affect engine starting? (only try for starting problems). N/A
28. Are all glow plugs in proper working order? New

29. During hard acceleration, do you have excessive black smoke? Not when it started
30. Do you have any unusual exhaust smoke issues? Just when starting.
31. Turbo check out - Pass/Fail - N/A
32. Indicate fuel that you are using: Bio-Diesel, #2 Diesel, SVO/WVO, other Diesel
32a. If running Veggie Oil fuel setup, indicate details of your conversion (homemade or packaged system). N/A
33. Are you using any fuel additives? If so, please list.
34. Upon unscrewing fuel cap, do you have a large vacuum formed in the tank? Yes
35. Do you have any service history available that might pertain to the problem you are having? NO
36. Please indicate any modifications to the vehicle that might help us diagnose better. Moved ECM under the driver seat.

Please let me know if I am missing anything and thanks in advance.
 

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You need to do LOAD TEST on batteries not Voltage test.
Batteries can pass voltage test but not LOAD test which measure the amp-acity (amperage capacity) of the battery.
I had battery with good voltage but when the load is applied, it shows some shortage aka voltage goes to 0.

Just saying.

Besides, replacing 1 battery in this truck can be detrimental to the new battery.
In other words, the old battery will take out the new battery to go bad.
 

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You should not have a vacuum in the tank. Leave the fuel cap loose for now or do the fuel cap mod in FAQ's
 

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How did you perform the lift pump test, as in FAQ's?
 

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Also no wait to start may indicate a faulty glow plug controller.
 

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Un-screw the gas cap first, then check if the glow plugs are working with a multimeter, and finally do the lift pump test before moving on to something else.
 

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You need to do LOAD TEST on batteries not Voltage test.
Batteries can pass voltage test but not LOAD test which measure the amp-acity (amperage capacity) of the battery.
Glad to hear somebody agrees with me about testing a battery.
 

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34. Upon unscrewing fuel cap, do you have a large vacuum formed in the tank? Yes
Are you sure it was vacuum and not pressure? I checked my cap by removing it and cleaning the threads with a clean rag. I put my mouth around the threads and blew, could not blow through it. I then sucked on it and it was clear, pulled air no problem. Cap has a one way check valve that allows air in but not out. Normally has pressure on the tank. Please no comments about my testing method, I know how it sounds. :)

If the bus was running and then the WTS light quit coming on and the bus wouldn't start, it just seems to me that the glow plug system has taken a crap. I would test that first. JMO
 

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Bad battery will cause WTS light aka GPs to not function.

It takes a lot of amperage to operate the GPs.
In a 95, if we unhook the batteries, the GPs will not turn on the first start after that.
That may be the same quirk.
Bad battery will cause no electric which means it is similar to the action of unhooking the batteries..
 

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Discussion Starter #10
First off, thanks to all that responded. All good points.

You need to do LOAD TEST on batteries not Voltage test.
Batteries can pass voltage test but not LOAD test which measure the amp-acity (amperage capacity) of the battery.
.
I had the battery checked both for voltage and load tested okay.

I am going down the list of all possible "will no-start cold" list per manual.

FUEL SUPPLY:

a faulty fuel filter.
b quality/grade or incorrect fuel (most likeliest cause per manual)
c air leaks fuel suction lines
d restricted fuel return line
e fuel tank cap not vented
f faulty injection pump
g faulty fuel supply
h water in fuel tank or filter
i faulty engine shut off solenoid
j inoperative fuel line or filter heater
k no fuel delivery

* As mentioned above, I check fuel delivery up to the fuel filter management and "t" handle drain and it delivers fuel but when I crack the injection line loose it does not get fuel. Now, if I have bad fuel wouldn't it still come out but just won't combust?

MECHANICAL SYSTEM:

a broken /scored piston rings (possibly not this because it started well when it did)
b incorrect rod bearing clearance
c low cylinder compression
d timing retarded
e timing advance
f starter cranking speed/batteries
g improper starting procedure

ELECTRICAL SYSTEM:
(this is what I suspect it to be but then again...)

a inoperative glow plugs (likeliest cause) I replaced all 8
b inoperative glow plug controller/relay
c housing pressure cold advance solenoid or switch

This came from the GM service manual. I posted it for future reference for anyone experiencing the same issue.

"Also no wait to start may indicate a faulty glow plug controller." my thoughts exactly

As far as the glow plug working properly, does the glow plug relay have anything to do with fuel delivery? Do combustion have to be present to suck fuel? my understanding was the PMD pump mounted driver was the one responsible for sending the signal to the injectors. So even with a proper working glow plug system if I don't get fuel it still won't start. Again, I am new at this.

"How did you perform the lift pump test"

I listened to the pump activate while someone started cranking the engine.

"You should not have a vacuum in the tank. Leave the fuel cap loose for now or do the fuel cap mod."

Do you mean leave the cap loose and then try to start it?

"Are you sure it was vacuum and not pressure?" It might be pressure.

"Bad battery will cause WTS light aka GPs to not function.

It takes a lot of amperage to operate the GPs.
In a 95, if we unhook the batteries, the GPs will not turn on the first start after that.
That may be the same quirk.
Bad battery will cause no electric which means it is similar to the action of unhooking the batteries.." I'm hoping that this is it. I checked how much a relay is and I might order one to eliminate this part.

I truly appreciate all your input as looking for a competent and trustworthy diesel mechanic where I am is hard and very expensive.
 

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Welcome to DieselPlace

Batteries need to be a matched set. If you have one that is new and the other is 4 years old then that could be an issue.
Make sure you have 12v. going to the Glow plug Controller and 12v leaving the Controller going to each glow plug with Ign on..

If you have issues with the Glow Controller then replace with AC/Delco brand #212-366.

Next, perform a lift pump test correctly: https://dieselplace.com/forum/showthread.php?t=39350
Also, make sure you have 12v. going to the lift pump at the connector.
If the liftpump fails the test replace the lift pump with AC/Delco EP158 and also replace the OPS ( AC Delco: D1815A -Vans).

Install a clear piece of fuel line on the return side of the Injection pump to help locate any air in fuel gremlins:
https://www.dieselplace.com/forum/63-gm-diesel-engines/21-6-5l-diesel-engine/736442-1999-gmc-bluebird-6-5l-td-pmd-resistor-settings.html#post7305306
 

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What means: "1 is less than 4?" Years? Months? Days?
 

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I truly appreciate all your input as looking for a competent and trustworthy diesel mechanic where I am is hard and very expensive.
By the way since OKDually hasn't done it, welcome to DP! From my experience here these guys are the best. So far everybody has been nice to me and more helpful than I ever dreamed. Kudos to the guys and or girls here at DP.

If you can read a volt meter and have some tools and aren't afraid to use them you can get help doing anything you need done. :)
 

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Discussion Starter #14
"By the way since OKDually hasn't done it, welcome to DP! From my experience here these guys are the best. So far everybody has been nice to me and more helpful than I ever dreamed. Kudos to the guys and or girls here at DP.

If you can read a volt meter and have some tools and aren't afraid to use them you can get help doing anything you need done." - This is really great to hear.

"Next, perform a lift pump test correctly" I have performed this by loosening the t handle and fuel come out when I crank it.

"Batteries need to be a matched set. If you have one that is new and the other is 4 years old then that could be an issue.
Make sure you have 12v. going to the Glow plug Controller and 12v leaving the Controller going to each glow plug with Ign on.." Might have to get another battery and GP relay.

Since I have fuel going to the fuel filter but not the injectors. I replaced all the glow plugs already because it was blowing white smoke at start up but since the "WTS" is still not illuminating I might as well replace the relay to eliminate that part.
 

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Unless you have deep pockets and little time, I would do checks before replacing parts. Get somebody to turn the key on while you have your hand on GP controller. It should click on when key is turned on and back off after about 8 seconds. If yes, with a test light check for battery voltage on the glow plug controller large lugs. One has power all the time, the other when key is turned on for about 8 seconds. Who knows you could have a burned out bulb in the instrument cluster. If no power coming out of GP controller you will need to refer to the service manual listed in the sticky FAQ and do a diagnostic check on GP system. You really need to rule out the GP system before going any further.
 

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You also mentioned that you hear a large "Whoosh" sound when you open the fuel cap.
This indicates you have a vacuum built up in the fuel tank and is not good.
You will need to modify the fuel cap by drilling a small hole for better ventilation as shown here:
https://www.dieselplace.com/forum/63-gm-diesel-engines/21-6-5l-diesel-engine/648770-fuel-cap.html#post6387506

Here is some more info on "No wait to start light":
https://www.dieselplace.com/forum/63-gm-diesel-engines/21-6-5l-diesel-engine/474063-my-glow-plugs-wont-cycle.html#post4750177

Go through and inspect all fuses and replace any that are bad
 

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Discussion Starter #19
Unless you have deep pockets and little time, I would do checks before replacing parts. Get somebody to turn the key on while you have your hand on GP controller. It should click on when key is turned on and back off after about 8 seconds. If yes, with a test light check for battery voltage on the glow plug controller large lugs. One has power all the time, the other when key is turned on for about 8 seconds. Who knows you could have a burned out bulb in the instrument cluster. If no power coming out of GP controller you will need to refer to the service manual listed in the sticky FAQ and do a diagnostic check on GP system. You really need to rule out the GP system before going any further.
I 100% agree. I can turn on the ignition and reach the GP controller/relay since it's arms reach because access to the engine is from inside of the bus. And no, I don't have deep pockets and have little time although I wish I did.
 

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Discussion Starter #20
PROBLEM SOLVED....well, at least for the first part. Bus starts and runs on 2nd and reverse.

Here's what I did:

Added 3 gallons of fresh diesel to rule that out but still no fuel in the injectors. Replaced 2nd battery with the the same brand (interstate MT-78) and replaced GP controller relay as well with OEM AC Delco, although still didn’t start and “WTS” light still did not illuminate. Fixed the leak under the fuel filter management by adding an extra seal. Tried spraying starter fluid but still wouldn’t start (I know I shouldn't but I was desperate). Was going to give up until I pulled the DRAC Module 16185965 VSSB Module Calibrator, Reman Vehicle Speed Sensor thinking it was the PMD because I couldn’t find it, while moving it I saw the "WTS" light come on and then I fired it and it started. Wire got loose while installing the battery. Starts better with a lot less smoke with new glow plugs. learned a lot and it definitely was a great feeling to hear it fire up again and to know that the injectors didn't crap out on me.

There's a great site called acuratediesel that has a step by step procedure on how to diagnose a 6.5 diesel. I should have caught it on step 1:

" 1. Visual inspection solves a large percentage of problems that would take much longer to diagnose by conventional techniques.
Spend a minimum 10 minutes in the engine compartment going over everything. Do not rush. Pay very close attention to wiring connectors and grounds.
There are a number of wires grounded at intake manifold bolts near the rear of the intake. Be sure that these are clean, tight and not broken.
There is a large round 15-way connector near the back of the intake manifold which joins the injection harness (which contains all the wires to the injection pump) to the main engine harness. Open this connector and ensure that the terminals are in good condition and not corroded as is common in northern trucks. If corrosion is present clean the terminals with a good electrical contact cleaner. Do not spread the terminals by inserting objects into them.
Pay special attention to any wiring looms where they pass over other objects such as A/C lines. Pick them up and be sure that no wires have rubbed through."

I am going to spend some time off and enjoy my second gear and reverse before moving forward to the transmission issue - lol.

I can't thank you enough to all the responded. I truly appreciate all the input and help.
 
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