no power low idle smoke

[isaacucv]

The problem I'm having ; I noticed the other day that I was losing power, and smoking a lot as I pulled into the driveway. I have replaced the lift pump with an electric fuel pump. I converted to a spin on filter and replaced all rubber fuel lines up to the injector pump. The truck starts OK, but idles very low. When I rev it up, the rpm's climb very slowly and there is a lot of fuel smoke, enough to make your eyes water. I have to put the throttle to the floor to get the truck to move at all. The smoke is coming out of both tailpipes , so I don't think its a bad injector. I have been in the tech manual enough to make my eyes hurt, and ask for help. So, what are your experiences here? I have read some other threads and found similar problems but no solutions or updates. I am open to suggestions...

 

[Cleptomaniac]

What color is the smoke?

 

[moriboy]

Any chance the intake is plugged? It sure sounds like it's not getting enough air to me.

 

[isaacucv]

What color is the smoke?

I see it as blue, but it isn't oil its definitely fuel.

 

[isaacucv]

Any chance the intake is plugged? It sure sounds like it's not getting enough air to me.

Yes I thought that. I ran it without the air filter and there was no difference. I looked in the intake with a light but I can't see anything out of the ordinary.

 

[mistaken1]

White smoke = unburnt fuel

Black smoke = lack of air

As I understand the diesel they need air. Basically the air flow is always wide open (or should be) and the throttle controls the amount of fuel injected (unlike a gas engine where the throttle controls the air flow).

You checked the intake, did you check the exhaust?

What about the return check valve? Is it clean and passing fuel?

Is it safe to assume you downloaded the manuals and followed the troubleshooting steps in them?

These are from the 34 manual

27. NOTICEABLE LOSS OF POWER
Step 1. Check fuel injector pump timing. (See paragraph 3-44)
Step 2. With engine running, check for compression leaks at all fuel injector nozzles and
glow plugs.
Tighten any leaking glow plugs to 10 Ib, -ft. (14 N.m). Tighten any leaking fuel
injector nozzles to 50 Ib, -ft. (68 Nom). Repeat check. If leaks are still found,
replace glow plug (see TM 9-2320-289-20) or fuel injector nozzle gasket (see
paragraph 3-5).
Step 3. Test each fuel injector nozzle. (See paragraph 3-36)
Step 4. Test compression of each cylinder, (See paragraph 3-2)

33. BLUE SMOKE (ENGINE OIL BURNING IN CYLINDERS)
NOTE
Foamy or milky oil or rust on engine oil level indicator are evidence of
contamination,
Step 1. Check engine oil level indicator for evidence of contamination.
Replace engine oil and engine oil filter if contaminated. (See
TM 9-2320-289-20)
Step 2. Replace crankcase depression regulator valve assembly. (See TM 9-2320-289-20)
Step 3. Check compression of each cylinder. (See paragraph 3-2)
Step 4. Remove cylinder head. (See paragraph 3-7) Inspect valve oil seals and valve
guides for damage.
Replace any damaged valve oil seals. (See paragraph 3-8 ) Repair valve
guides if damaged. (See paragraph 3-8 )

 

[mistaken1]

From the 20 manual

28. NOTICEABLE LOSS OF POWER
Step 1. Inspect air cleaner filter and polywrap.
Replace air cleaner filter if required. Clean polywrap if required. (See
paragraph 3-9).
WARNING
Diesel fuel is flammable. When disconnecting fuel lines to test fuel flow,
direct fuel spray away from source of ignition. A fire extinguisher must be
on hand in work area. Failure to follow this warning may result in serious
injury or death to personnel.
Step 2. Check for restricted fuel filter. Bleed air from fuel system. (See paragraph 3-17)
If fuel flow is insufficient, replace fuel filter. (See paragraph 3-17)
Step 3. Check for leaking or restricted fuel lines.
Tighten fittings or replace leaking or restricted lines. (See paragraph 3-13 or
3-14)
WARNING
Before checking for improper positioning and damage, allow exhaust
system to cool. Failure to follow this warning will result in serious burns.
Step 4. Check tailpipe, muffler, and exhaust pipe for improper positioning and damage.
Reposition and tighten mounting hardware.
Replace any damaged components. (See paragraph 3-27)

29. EXCESSIVE EXHAUST SMOKE DURING OPERATION
Step 1. Inspect air cleaner filter and polywrap.
Replace air cleaner filter if required. Clean polywrap if required. (See
paragraph 3-9)
Step 2. Check for contaminated fuel by draining fuel from fuel filter draincock into suitable
container. Check color of fuel to determine if the correct fuel is in fuel system.
Drain fuel and replace if contaminated or incorrect fuel is in fuel system.
WARNING
Diesel fuel is flammable. When disconnecting fuel lines to test fuel flow,
direct fuel spray away from source of ignition. A fire extinguisher must be
on hand in work area. Failure to follow this warning may result in serious
injury or death to personnel.
Step 3.
Step 4.
Step 5.
Check fuel pump operation. Disconnect input fuel line at the fuel filter. Disconnect
pink lead from fuel injector pump. Use a quart capacity container and crank engine
for 15 seconds. Container should be at least ¼ full or contain ½ pt (0.23 I) of fuel.
Install low pressure gage in fuel line. Crank engine for 15 more seconds. Fuel
pressure should be 5.5-6.5 psi (38-45 kPa). Connect fuel inlet line to fuel filter and
connect pink lead to fuel injector pump.
If fuel flow is insufficient, replace fuel pump. (See paragraph 3-10)
Bleed fuel filter. (See paragraph 3-17)
Check crankcase depression regulator valve (CDRV) and hose for restrictions.
Inspect hose and air intake manifold for evidence of oil.
Clean off all traces of oil and clear restrictions or replace CDRV and hose as
required. (See paragraph 3-5)

I assume none of these things cured the problem.

 

[bigflew]

Sounds like the injection pump to me mine did the same thing went through the tm and finaly replaced the IP runs great now. You can get them rebuilt fairly cheep (200 -300) but I bought a pump and injectors(rebuilt) at the same time.

 

[isaacucv]

Well I took the fuel return valve and broke the glass ball out. Now its running perfectly. It was full of rust colored debris. I will source an injection pump asap though because it must be going bad if there's that much crap floating around in there. Hopefully it will hold up for a couple days. I will update the post as needed. Thanks for all your help guys!

 

[dmilkman589]

there is no valve in mine, just a nipple right to the line. is that bad?

 

[isaacucv]

there is no valve in mine, just a nipple right to the line. is that bad?

That may be the return valve you are looking at. It takes a 9/16 deep socket. It's a short little valve.

 

[dmilkman589]

but there is no valve on this. ive seen the picutures of the nipple screwed into the valve. mine is just nipple no valve. could that be causeing any of the power loss im experiancing

 

[isaacucv]

but there is no valve on this. ive seen the picutures of the nipple screwed into the valve. mine is just nipple no valve. could that be causeing any of the power loss im experiancing

Its hard to say. What kind symptoms are you dealing with? I broke the glass ball out of mine and it runs and pulls better.

 

[IROC99]

Where is the fuel return valve? I want to check mine also. I am having similar problem.

 

[dmilkman589]

white smoke. blue smoke. no power. its a pice!!!

 

[isaacucv]

Where is the fuel return valve? I want to check mine also. I am having similar problem.

On top of the IP. There is a piece of rubber fuel line, disconnect it and unscrew the valve with a 9/16 deep socket.

 

[isaacucv]

white smoke. blue smoke. no power. its a pice!!!

Have you done anything to it otherwise? Is the lift pump good? Have you switched to a spin on style fuel filter? Is the smoke coming out of each tailpipe equally?

 

[dmilkman589]

equal smoke. o and it take forever to start