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Failing Injector Pump Symptoms?

70K views 10 replies 8 participants last post by  JCDiesel 
#1 · (Edited)
What are some of the symptoms of a failing injector pump? I have been experiencing what seems like a dead cylinder (seems to be getting worse like 2 dead cylinders now). I thought it might be a bad/clogged injector. I would say it sounds like a dead cylinder not just an occasional miss.

It doesn't seem to be get better when warmed up either. I was looking around under the hood last night, and the IP sounded a little "grindy", but this is a recent purchase, and I don't now what it's supposed to sound like.

1. Does the engine crank, or 'turn over'? yes
1a. Does the engine start and run? yes, quickly within 1-2 sec crank
1a1. If the engine does not start - Crack injector line: do you have fuel? Yes/No
1b. Do you have a Wait To Start Light & the amount of time (seconds) lit. ~10sec
1c. Ambient Condition (temperature outside indicate F or C) ___50°-70°F
1d. Engine Cranking speed (if you have an accurate tachometer).
1e. Are you experiencing stalling? No
1f. If Stalling, describe (upon startup only, down the road, hit a bump etc)
1g. If Stalling, do you notice loss of dash or instruments?
-note if experiencing stalling,you must indicate PMD location in #24.

1h. Check turbo inlet and air filter for obstructions. Cone filters have lost disk and stopped air to turbo. Seems fine
1i. In a no-hot start, pour a bottle of room-temp water on the injection pump.
1.1 Lift pump test - - lots of fuel
2. Service Engine Light while running?- off
2a. Service Engine light does glow during start/cranking/bulb check: bulb check only
3. Model year 94
3a. Odometer reading (indicate if in miles or km) 300600m
3b. Miles on major engine components if been replaced (example Injection pump) unknown
3c. Indicate the model number on the Injection pump (starts DS4 or DB2......) will check ,did notice a metal tag with what looked like orange paint securing the screw
4. Have you scanned for engine codes? (varies by pre/post 96) not lately
5. List exact results on engine codes:
6. Air Filter condition (visual check) seems well K&N cone
7. Fuel filter condition (freshly changed/condition unknown/mileage since changed) changed this week, old one did not look bad
8. Condition of Battery terminal connections (removed, cleaned and tightened) One side is good, had it loose within a month
8a. Known condition and age of the batteries. cranks easily
8b. Are batteries of differing age or are they a matched set? matched set
8c. Condition of Major Grounds. (same drill as batt - removed, cleaned, retightened) unknown
9. Upon cold start, does the radiator hose get hard quickly? replaced thermostat 600m ago
10. Upon cold start, do you have excessive white smoke? puff
11. Do you have excessive cranking time before the engine starts? no
12. Have you used the block heater, and does this effect engine starting?(only try for starting problems)
13. During hard acceleration, do you have excessive black smoke? no
14. Do you have any unusual exhaust smoke issues? no
15. Turbo check out - pass
16. Do you have an EGR on the engine? (An F or an S engine code 8th VIN digit) no
17. Indicate if you know if it’s a 2500HD
18. Indicate fuel that you are using: #2 Diesel,
18a. If running a VO (Veggie Oil fuel) setup, indicate details of your conversion (homemade, or packaged system)
19. Are you using any fuel additives? If so, please list. tried fuel injector cleaner on current tank, will check brand
20. Please indicate geographic region you are in: (example: Texas or Canada) Oklahoma
21. Do you have any service history available that might pertain to the problem you are having?
22. Please indicate any modifications to the vehicle that might help us diagnose better. 3" downtube into 4" exhaust from muffler
23. Upon unscrewing the fuel cap, do you have a large vacuum formed in the tank? have seen some pressure diff on accasion but unsure if pressure or vacuum
24. Location of PMD/FSD? On the pump/remoted over intake/remoted out of engine bay (please specify placement specifically) bumper
24a. If remote mounted, describe wiring harness (homemade or purchased from a vendor?) purchased
24b. Indicate the location and condition of the FSD/IP grounding wire. unknown
25. Are ALL glow plugs in proper working order as per this thread?
unknown but starting is no issue
 
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#2 ·
can you hold a steady 2000RPM in park? and a steady idle of about 650?

if you have 1 or 2 cylinders missing, i'd suggest you do a compression check.
 
#3 ·
Mine started with random shutoffs. It would fire right back up and then you could drive it 30 minutes or so and it would do it again. Then it got to where it would crank up and shut off after about 1 minute. Let set for a bit and it would crank back up and run for a minute or so.
 
#4 ·
It seems to idle fine at around 650rpm, And I don't see why it wouldn't idle at 2000 with my foot on the throttle.

It seems to drive OK, It just feels rough especially at higher loads i.e. driving down the highway. At idle it's hardly noticeable.

I had it idling in the driveway this morning, and from inside, I could here a definite miss, it wasn't a smooth rumble, but a rumble with a missing beat.

What's the best way to check compression? pull glow plug? I take it there is a special gauge for diesels. I can't really pull a spark plug and use my tester.
 
#5 ·
lol, nope you cant. you need a diesel compression tester kit. goes in the glow plug hole, and the gauge will read a minimum of 800 if you want it to survive. i think most of them go up to 1000, and these engines are specced for 400(399 or something like that..400 is good)
 
#6 ·
Bobcat sounds like you had PMD issues not IP. Correct me if I'm wrong.
 
#8 ·
Bobcat sounds like you had PMD issues not IP. Correct me if I'm wrong.
Replaced the lift pump to start with and then the PMD trying to figure out what it was. It would still run at this time for 30 minutes or a little longer. When it got to where it would just crank up and run for a minute or 2 and then quit replaced IP and now all has been good for 10,000 or so miles. I think the OPS was maybe what started it all though by not letting the lift pump work thus making it harder on the IP.
 
#9 ·
Hello everyone I'm new to this and the diesel word I have just bought a 99 chevy 3500 dully with the 6.5 and it all seemed fine when I test drove it so I bought it and as I got on the freeway I noticed it would not do 70mph and I had a hard time keeping g it at like 67-68 Mph.i know they are not the fastest motors on the road but it seems like I have to feather the gas pedal to get it to shift and get it up to speed any help on this issue would be great full so I do think have to play the guessing game or the part changing game I don't have that kind of money to just guess with thank you again
 
#10 ·
Welcome to the forum :thumb:

First, I would create a new thread here in the 6.5L section to give you a good set of responses instead of being crammed up in this thread and possibly confusing others. :HiHi:

Second, be sure to fill out your signature by clicking on " User CP"
then click on " Edit you signature".
Fill out your vehicle information and any modifications know about it.
Be as descriptive as possible then click on save.
 
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