Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

startingproblems sometimes when halfwarm

Discussion in '1982-Present GM Diesel' started by ronny.f, Jun 1, 2003.

  1. ronny.f

    ronny.f Registered Member

    Joined:
    May 20, 2003
    Posts:
    8
    Likes Received:
    0
    Location:
    Vetlanda, Sweden
    Hello Sweden calling !

    I have a problem with my 6.2, sometimes it won´t start when it´s halfwarm. The engine starts with no problems but after about 5 seconds it´s stops again and after that it doesn´t start, if i wait for 10-15 minutes it will start with a wery irrating idle for 4 secunds and then its go back to normal. These problems comes only when the engine is halfvarm. Please help me with oppinions on this.

    / Ronny
     
  2. rugger03

    rugger03 1/2 ton status

    Joined:
    May 14, 2000
    Posts:
    829
    Likes Received:
    0
    Location:
    around
    Ronny- Good to see you here. Few questions first how many miles are on your engine total? how many on the injector pump and injectors? Whens the last time you've replaced the fuel filter? Be able to help more with more information, will check back in soon.
    cheers,
    rugger
     
  3. BlueBlazer

    BlueBlazer 1/2 ton status

    Joined:
    Feb 15, 2001
    Posts:
    1,940
    Likes Received:
    0
    Are your glowplugs turning on at the time you have starting troubles? It seems most 6.2s need a little glow time even when they are partially warmed up. If the glowplugs are working, then does the truck start OK when fully warmed up?
     
  4. ronny.f

    ronny.f Registered Member

    Joined:
    May 20, 2003
    Posts:
    8
    Likes Received:
    0
    Location:
    Vetlanda, Sweden
    Hello again !

    I just bought the van for 1 month ago and the previous owner told me that the pump was rebuilt for 2 years ago or around 20000 km = 12500 miles so i don´t thats the problem. Regarding the total amount of miles the odometer says 81490,5 miles, i will try to replace the fuel filters this weekend

    / Ronny
     
  5. ronny.f

    ronny.f Registered Member

    Joined:
    May 20, 2003
    Posts:
    8
    Likes Received:
    0
    Location:
    Vetlanda, Sweden
    i have bought new glowplugs and a controller because the old ones didn´t work so i have used startgas for starting the engine but when it´s halfwarm that doesn´t work either.
    I will replace the parts this week.

    / Ronny
     
  6. doctor4x4

    doctor4x4 1/2 ton status

    Joined:
    Jan 22, 2002
    Posts:
    1,450
    Likes Received:
    0
    Location:
    Los Angeles
    First of all Welcome !!!
    2nd of all :

    DUDE D O N T USE START GAS !!!!!!!

    if its any thing like our startingg fluid you might Blow up your motor does it contain Eather or Ethinal ??? if so DONT USE IT
    ya wanna use wd-40 do ya know what that is ?? i don tknow if they sell it there or not ??
    any ways i just went through this my self Exactly what u are and 4 me it was a combo of things but mostly a air leak in the system and glow plug wernt "recycling"
    hope it helps
    Randy
     
  7. ronny.f

    ronny.f Registered Member

    Joined:
    May 20, 2003
    Posts:
    8
    Likes Received:
    0
    Location:
    Vetlanda, Sweden
    i have changed the controller and glowplugs to 60g:s and the controller from 85-94. The result is that the glowplugs recycling the way thay skould and the engine starts fine when cold. Don´t know how it´s is when halfwarm but i havn´t noticed something strange yet.

    THANKS / Ronny /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif
     
  8. Ronnie4wd

    Ronnie4wd 1/2 ton status GMOTM Winner

    Joined:
    Jun 4, 2002
    Posts:
    749
    Likes Received:
    0
    Location:
    Stockholm.Sweden
    Yes we have WD-40 here don´t know if it´s the same though.If the problems remain the same I think you should try to cool the injector pump just take a can of water and pour it on the pump.Do you run any additive in your fuel? The diesel fuel here is very dry.
     
  9. rugger03

    rugger03 1/2 ton status

    Joined:
    May 14, 2000
    Posts:
    829
    Likes Received:
    0
    Location:
    around
    Ronny-
    Your truck just needs a good shot of Aqvavit or two and it will be fine, or is that me. These are some excerpts from another diesel specific online reference area, hope it helps. I know a guy here that is having the same problem hes going to try the "oil in fuel" trick to see if that will work. I would use less than more if doing it.
    No Start Hot
    High mileage or otherwise worn injection pumps can produce a "no start" or a "hard to start" condition with an engine at operating temperature. Hot summer temperatures usually make this condition worse.

    Elevated temperatures can affect the injection pump's ability to produce the necessary fuel pressure during a hot re-start. Usually, once the engine is started, it will run more or less normally, but will again be difficult to start once the specific conditions are duplicated.

    The usual test for this condition is to mix clean new motor oil in with the diesel fuel at a concentration of between 5-10% oil. The introduction of oil will raise the fuel viscosity and usually allows a worn injection pump to produce fuel pressure levels high enough for normal hot starting. If your diesel engine starts easier with the treated fuel, your injection pump will need to be replaced. However, all other possible contributors to this problem need to be ruled out before replacing the injection pump.

    Low cranking speed and/or low compression
    A diesel is a compression ignition engine. Combustion occurs when the heat generated by the high compression reaches the flash point of diesel fuel.

    A higher cranking speed doesn't allow as much time for the compression pressure to leak down during the compression cycle. If your engine cranking RPM is lower than you remember, you need to determine if the problem is caused by weak batteries, battery cables, or a bad starter. If your batteries and cables are good, and a jump from another good battery doesn't significantly increase the starting RPM, then the starter is probably close to failure and will require replacement. You should have seen a starting RPM drop at some point during the last month or so if the starter is going bad. Before buying any new parts, you should go over all of the battery terminals and cables to ensure solid connections. A corroded terminal can cause one battery to drop out of the circuit and put the full starting load on the one remaining battery.

    The Stanadyne Injection pump requires a minimum cranking speed to generate sufficient fuel pressure. A higher cranking speed makes it easier for the pump to develop the necessary fuel injection pressures. Minimum cranking speed is 100 rpm cold, and 180 rpm at operating temperature.

    Poor compression pressure rarely happens overnight. Generally, a diesel will get progressively harder to start over a fairly long period of time. Cold weather aggravates this situation and you should take ambient temperature into account when diagnosing a compression related "no-start" problem. New engines will have close to 400 psi of compression pressure at cranking speed and a high-time engine could be as low as 275 psi. If your compression pressure is close to 275, then it's probably time to think about rebuilding the engine. A high mileage engine can be helped with fuel conditioner, but if the situation persists and none of the above helps, you'll be faced with the expense of a complete or partial engine rebuild.

    Cheers, rugger
     
  10. BlueBlazer

    BlueBlazer 1/2 ton status

    Joined:
    Feb 15, 2001
    Posts:
    1,940
    Likes Received:
    0
    If you guys would read his original post, you would see he does not have the problem when the engine is fully warmed up, but when it has been sitting for a while and still warm. Obviously an injector pump would not lose its pumping ability with as he calls it halfwarm fuel. That and he already said changing the glowplugs and controllers seems to have cured the problem.
     
  11. rugger03

    rugger03 1/2 ton status

    Joined:
    May 14, 2000
    Posts:
    829
    Likes Received:
    0
    Location:
    around
    so your saying that a warm injection pump will not loose its pumping ability when warm and the warm fuel is thinner?
    He does say using starting fuel in the half warm engine will not sart it either. Just trying to help out but Obviously i shouldnt say anything seeing as your the pro.
     
  12. BlueBlazer

    BlueBlazer 1/2 ton status

    Joined:
    Feb 15, 2001
    Posts:
    1,940
    Likes Received:
    0
    Well if he doesnt have any trouble starting it when its fully warmed up, but he does when its somewhat warmed up and the fuel is cooler, theres a damn good chance its not an injector pump.

    I know you are trying to help, but when you tell a guy he might need an injector pump, he might assume you are correct, and blow hundreds of bucks on one and it wont change his hard start condition. All the symptoms point to a glow plug problem, and that seems to have been the problem, but without personally working on his truck, my diagnosis may be wrong.
     

Share This Page