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*UPDATE* Truck hard to start. Dieseldan look Think I got it!!

Discussion in '1982-Present GM Diesel' started by 84CUCV, Jan 21, 2003.

  1. 84CUCV

    84CUCV 3/4 ton status Premium Member

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    Dieseldan, I don't see how the sensor can be leaking there. It looks new brand new. I just changed the fuel filter. GP are new so is the relay and the controller. How do I check them? maybe I was sold a bad one? I have no clue what it could be. Any other ideas? Thanks again Mike
     
  2. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    I'm a total newbie to diesels too and my 6.2 that i recently swapped in seemed difficult to start for a while. I had a small leak at the supply line to the lift pump. It was still kinda tough when cold but I've learned to hold the key a little longer and it usually flashes up after 5 or 6 seconds now.

    One thing I found was some instructions on the visor of our parts truck. It said for temps above freezing hold the gas pedal down halfway...temps below freezing hold it to the floor. I find that works pretty good for my truck.

    Rene
     
  3. 4xfreak

    4xfreak Registered Member

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    One thing I found was some instructions on the visor of our parts truck. It said for temps
    above freezing hold the gas pedal down halfway...temps below freezing hold it to the floor.
    I find that works pretty good for my truck.

    Rene /forums/images/graemlins/thumb.gif
    This is really good advice I found this trick out as soon as the cold weather headed my way and sure enough it works every time, awesome advice! /forums/images/graemlins/cool.gif
     
  4. Tybee

    Tybee 1/2 ton status

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    What about you lift pump? And does it start right up after its hot?
     
  5. DieselDan

    DieselDan 1/2 ton status

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    Do you have a (lack of) fuel problem, ie: no smoke at start up OR do have a glow plug problem: smoke but no start?

    The health of the GP can be checked with a voltmeter connected to the GP solenoid mounted on the firewall. 24V (battery voltage +/-) with the GPs OFF (going to the solenoid). 12V +/- (coming out of solenoid) with the GP cycled ON. Check this and tell me what ya got.

    That filter-mount air leak thing is like that sometimes. I never could "see" where the problem was. There are other places it can leak air, but the mount is definately the most common. /forums/images/graemlins/wink.gif
     
  6. 84CUCV

    84CUCV 3/4 ton status Premium Member

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    My friend checked the gp with a wire that clips on the ends and a light bulb. You know how it goes. You put it on the positive post and clamp each gp and when lights is on it good. All gp are good. Relay cycled fine. Could it be the resisters? My 1009 is all stock. Had to use it so this is what I got. It was 20 out and the motor was cold. GP were on for 11 seconds. One side of the truck had white smoke the other had black smoke. First try 30 seconds of cranking with a cloud of smoke. Second try 30 more second with one more cloud. Third try about 47 seconds and with a cloud it started. After it was started white smoke out both sides. I went out it was fine or so I think. it was in a parking lot for about an hour and a half. Took about 11 seconds to start. how do I check the fuel system for a leak? Any other advice? thanks Mike
     
  7. BARRAZA

    BARRAZA 1/2 ton status

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    This is really strange, white smoke out one side and black out the other??? I agree it sounds like an air leak, but also think you need to go back to the basics and answer some questions so everyone can help track down the problem:
    1. Do you know that this truck ran and started ok before you started the latest work?
    2. Have you ever checked the compression, if so what were the numbers?
    3. If this truck was a non-runner when you got it, have you drained and or pulled the tank for a look inside? When I got my CUCV, it hadn't been run in years and had about a pint of water and lots of mud in the tank, and the pickup was nearly blocked.
    4. Once it finally starts and is warmed up, how does it start after a 15 or 30 min shut down, ie long enough for air to leak in from a leaky injector, but not long enough to cool off.
    5. Did you have the injector pump rebuilt?
    6. Have the injectors been tested?
    7. Are you sure the pump is timed right?
    8. Have you tried putting a clear piece of tubing on the fuel return line? If so, do you see bubbles at startup? Or continuously?
    9. Is your HPCA hooked up and working?

    Some things you may want to try:

    Rig up a way to feed fuel straight to the fuel pump inlet to eliminate tank and line problems upstream. When I was doing mine, I used a plastic jar hung from the hood like an I.V. Put two nipples in the lid, one feed and one vent - worked fine. You can also use the same rig to feed fuel straight to the injection pump line, the pump only needs 2 psi to operate so it should probably work.

    If you dont want to spend the bucks to test the injectors, at least take them apart and clean them. Its very easy, the injector housing unscrews and everything inside comes right out. Just make sure you get them put back together in the right order, and it would probably be a good idea to not mix up parts from one to another. Its possible you have an injector stuck open.

    A minute forty five of cranking is a LOT. Make sure you are letting the starter cool or you'll soon be buying a new one.

    Now that I got mine fixed, it starts before I can get "one thousand one" out of my mouth, at 35 degrees. Faster than any gasser I've ever owned. /forums/images/graemlins/grin.gif

    Good Luck
     
  8. DieselDan

    DieselDan 1/2 ton status

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    Humor me and put a Voltmeter on your relay and tell me your readings (Cycle On & Off). It will smoke some til the combustion chambers warm up (engine run time and some "after glow" cycles). Your resitors could be bad but your GPs would be (will be) all dead in short order. Did I ask you to test the system voltage yet? /forums/images/graemlins/rotfl.gif If you drop just one glow plug on a CUCV, you'll soon burn out all the rest. /forums/images/graemlins/eek.gif

    Baraza brings up some good points. If your HPCA and/or high idle isn't working it's gonna start like crap in this weather. Check to see if you got power on the idle solenoid (on the linkage) or to the HPCA connection (green wire IIRC), both are powered by the thermoswitch under the right exhaust manifold.

    Hey, If it's smokin' it's getting fuel /forums/images/graemlins/thumb.gif
     
  9. 84CUCV

    84CUCV 3/4 ton status Premium Member

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    Ok.....I will let you guys know what i find. Thanks again Mike
     
  10. 84CUCV

    84CUCV 3/4 ton status Premium Member

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    Here is a list so all of you can see what is up with my rig.....

    1. Now that I think about it. It did have a hard time starting to. I never had a chance to track it down before I had to other work to it.
    2. I will check the compression as soon as I get a gauge Then I will let you know.
    3. When I first got it. It ran great. Ever since the first fuel filter change It has been all down hill. No, I never drained the water. I thought the light would come on when it was time? Never even thought of checking the tank.
    4. It starts OK, but it is not three seconds and it is going. More like 7 or 8.
    5. Yes, the injection pump was rebuilt about 3,000 ago, from a little shop. I should have gotten one from Kennedy or Us Diesel Parts.
    6. The injectors where never tested. I will let you guy know what I find out.
    7. I am going to get the pump timed.
    8. Bubbles on startup? Or continuously? That is a new one. What does that mean?
    9. The HPCA is the cold start thing on the side of the pump. that makes the rpms stay up till it gets warm? if that is it. It is working.

    Once again thanks for the help guys. Mike
     
  11. BARRAZA

    BARRAZA 1/2 ton status

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    Mmmmmmmmmm
    I think you may have a couple of things going on here, a heat and a fuel problem combining to make your misery. Starting well (comparatively) after being warmed up indicates a heat problem - compression / glow / cranking speed. But if things got worse after changing filters, you probably have a air problem also. Try these things and this is probably a good order to do them.

    1. Finish checking your glow plugs like DD said above
    2. Check that HPCA - It's not the solenoid that makes it idle fast, but it shares the 12v signal to operate. It is on the pass side of the pump. Use a jumper from the pos 12v battery terminal to the connector and you should be able to here the solenoid click. The HPCA advances the timing and makes cold starting easier.
    3. If you put in 60g glow plugs, I think they dont warm up quite as fast, try a double cycle before starting to see if there is a difference.
    4. Replace that filter and filter base. You may have cracked the base where one of the tubes enters if you rocked the filter back and forth when replacing it. Dont know about where you are, but 6.2's are starting to become common in junkyards around here, you should be able to find a used one easily.
    5. Put a piece of clear tubing in the fuel return line from the pump. Lots of bubbles is an indicator of air leaks.
    6. When you installed the injector pump, did you line up the timing marks? An old engine with timing wear will probably need the timing advanced a little to make up for the wear. Try moving the pump mark about a line width towards the drivers side to advance the pump, not more than 1/8 inch.
    7. Check the cranking speed - Disconnect the fuel solenoid wire at the pump. Pull a glow plug and count the puffs coming out in 15 seconds of cranking, multiply by 8 for RPM, 100rpm is the minimum
    8. Check the compression. This is kind of a pain if you dont already have a diesel compression tester because most gas types only read to 300psi and the min for a 6.2 is 290psi and they top out at 400 or so. I made an adapter by welding an air fitting to an old drilled out glow plug and used my gas compression gauge, I read it using a mirror from the drivers seat because I didnt want it blow up on me. Mine read about 25psi past the end of the scale. I know its not safe, try at your own risk.
    9. The water in fuel light comes on when the is water in the fuel FILTER, not the tank. I would drop the tank as a last resort.
     
  12. 84CUCV

    84CUCV 3/4 ton status Premium Member

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    Here is what I got.
    DD on the voltmeter. I set it to 25 DC and it read 24 then it clicked and went to zero. What the heck does that mean??

    Barraza
    1. All gp are good.
    2.HPCA Herd it click.
    3. They are 13g gp.
    4. Need to find a filter base first. Anyone have one to sell? Or could I go with a better after market version?
    5.The clear hose I will do tonight.
    6.The timing marks are perfectly lined up. The truck had 14000 on it.
    7.Will check cranking as soon as the batteries charge.
    8. I going to get a compression gauge tonight.
    9.The water in fuel light never comes on, as a last resort I will drop the tank.
    10.How do I check the pump timing. Can I do this myself?

    How do I check the system voltage and the thermoswitch?
    What does HPCA stand for? Thanks for the help guys. I need to get this up and running. I am losing to much money on this! /forums/images/graemlins/1zhelp.gif /forums/images/graemlins/1zhelp.gif /forums/images/graemlins/1zhelp.gif /forums/images/graemlins/1zhelp.gif
     
  13. DieselDan

    DieselDan 1/2 ton status

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    Something is NOT right. Voltage going into the solenoid should be 24V - GP cycle OFF, then is should drop to near 12V when the solenoid closes - cycles ON. The ballast resistors work in conjunction with all eight glow plugs to drop 24V down to 12V. One less glow plug and the voltage will rise approximately 1.5 Volts.

    On the output side of the solenoid it should simply be 12V ON, zero V OFF.

    Assuming you were measuring the output, your have no resistance load from the Glow Plugs. Does it still start at all? If it won't start, I'm afraid all of your plugs are dead /forums/images/graemlins/frown.gif

    If it does still start, you got something really amiss and I don't know what. /forums/images/graemlins/blush.gif

    PS. HPCA- high pressure cold advance IIRC
     
  14. 84CUCV

    84CUCV 3/4 ton status Premium Member

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    Dan, What i did was I put one on top of the relay and one on the bottom. I will do this again in the morning. This is really starting to piss me off! I think I just might make it a 12v system. Thanks a lot for the help! Mike
     
  15. DieselDan

    DieselDan 1/2 ton status

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    Measure from the input terminal (ballast resistor side) to chassis ground.
     
  16. 84CUCV

    84CUCV 3/4 ton status Premium Member

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    Finally got back my TM 20. Did what it said from 2-39 on. I believe the resistors and the relay are gone. As are the gp. So this is what I will be doing next. Other then that I found that the fittings on the back of the injection pump are wet. So will tighten them down. Is there wrench to get in there after I take the intake off? thanks Mike
     
  17. DieselDan

    DieselDan 1/2 ton status

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    On the TM I looked at it 2-19. Resistor failure is not too common but it does happen. Did they fail the resistance check? Why do you think the solenoid (relay) it bad, it was switching (ON/OFF) right?

    Have you done glow plugs before? They can be fun /forums/images/graemlins/rolleyes.gif TRY not to break them.

    Some of the fuel lines can be accessed with a crowsfoot socket on an extension. (it easier on a HMMWV, you can pull the dog-house cover.)
     
  18. 84CUCV

    84CUCV 3/4 ton status Premium Member

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    The resister pegged my meter and then blow it. It was switching on and off. I had the fun with GP already. thanks Dan
     
  19. 84CUCV

    84CUCV 3/4 ton status Premium Member

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    Found a relay in all me parts. Put it on. Just to see if that would work. A few seconds right up and going. I am going to check a few things. Just to make sure everything is working right. thanks a lot for the infomation. Mike
     
  20. 84CUCV

    84CUCV 3/4 ton status Premium Member

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    Re: OK.....I am about to give up My truck is real hard to start. Dieseldan look

    Started fine when I went out last night. Now it is right back to. If I find out what it is I will let you know. Mike damn This is getting old now....
     

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