740 & 760 First start checklist / troubleshooting after overhaul.

JamesMJamesM (@JamesM) Melbourne
edited March 14 in Troubleshooting
Hi all,

Having recently buttoned up everything after doing some somewhat major modifications to the wagon aka Misty aka the 740t I'm seeking advice as I'm hesitant to turn the key on the off chance I've missed something and fry some electrical component or snap a belt etc.

Can some of you chime in with advice as to some sort of sanity checklist I should run through to ensure I don't do any damage that would then set me back again.

Ive outlaid to me quite a sum of money in parts on this thing and have done a manual swap, bigger exhaust valves, turbo, coilovers, wasted spark, Efan, intercooler and piping, head work among other things.

I just don't want to rush to start it and have something bad happen and not know how to diagnose it or fix it.

Car is on stands in my shed until I verify it runs as it should, then I'll be driving it straight to a wheel alignment centre while bedding in my brakes and ensuring my afrs are correct.

I'm a backyard mechanic and don't claim to know alot, 90 percent was learnt through you kind people and the greater Volvo community and forums.

Any advice would be greatly appreciated.
Thankyou :)
James

Comments

  • People learn through their own experience, or through others experiences. Get in the car, fire it up (if it will start) and hopefully you did all your jobs right. If it doesn't, something somewhere isn't working, that's when your diagnosis skills come out. Check for fuel supply, spark, compression and go from there

    Good luck
    hamsandwich
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    edited March 15
    People learn through their own experience, or through others experiences. Get in the car, fire it up (if it will start) and hopefully you did all your jobs right. If it doesn't, something somewhere isn't working, that's when your diagnosis skills come out. Check for fuel supply, spark, compression and go from there

    Good luck
    Ramrod come on please don't ever advise anyone to just start it and "hope for the best."

    There's a few steps to make sure when you crank it you won't grenade the engine.
    1. check no rags left in the turbo/intake inlet/outlet ๐Ÿ˜‰
    2. put a ratchet on the crank and turn it over by hand (clockwise) two full turns to make sure there's clearance between pistons and valve train and that your timing is basically in the region of correct.
    3. disconnect injectors and crank engine and verify you're getting oil pressure.
    4. check hoses are all clamped properly especially in the charged part of the intake

    Another thing you can do is take a multimeter in continuity mode, and check all your expected grounds have continuity to ground, and your +12V lines do not have continuity to ground. If you replaced the fuel pump, check you didn't wire it backwards ๐Ÿ™ƒ

    Now you can try to start it and even if there are electrical issues, you're unlikely to do any mechanical damage.

    Once you've got it running for a couple minutes, switch it off and slacken and retighten the timing belt tensioner.
    JamesMtimbo
  • Thanks @jamesinc there are things there that I wouldn't have known to do. This is the kind of advice I was after. Especially with hand turning the crank and checking electrical connections.
    If anyone else has any other useful advice based upon experience please feel free to chime in.
    Will update on my progress :)
    egads
  • Double check all the bolts and nuts you can reach are done and tight?
  • Sorry.

    My mistake.

    Make sure there is oil in the crankcase. Never assume it's full. Make sure the drain plug is installed. Oil filter on. Double check you have coolant in the reservoir. Radiator hose clamps on. Make sure the cam timing is right. Spark plug leads are in the right position. Crankshaft vibration damper bolt tight. Cam belt tensioner................tensioning. Starter connections intact.

    THEN start it.

    My previous contribution was assuming the above had already been done, since the OP had done all the work by himself. I guess I missed the obvious points

    So...... have you started it yet?
    JamesM
  • Is there a way to check the injectors are working correctly before starting it? I had one stay wide open when the ignition was turned on. It filled the cylinder with fuel but not quite enough to hydro lock it luckily. Less than ideal but a rare thing I would imagine.
    '88 245
    '88 245 turbo
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    edited March 18
    Is there a way to check the injectors are working correctly before starting it? I had one stay wide open when the ignition was turned on. It filled the cylinder with fuel but not quite enough to hydro lock it luckily. Less than ideal but a rare thing I would imagine.
    If on LH-2.4, it has a test mode built into it for the injectors. With debug probe in pin #2:
    Turn on ignition

    Depress diagnostic socket button three times. Each
    press should last for at east one second but not more
    than three.

    At this point the injectors will begin to operate, followed by the idle valve, etc. The diagnostic socket
    light diode will fIash in a continuous pattern.
    The control function will repeat itself until interrupted,
    either by turning off the ignition or by changing control
    function via the selector button.

    Then put your finger on each injector, you should feel it clicking as it opens and closes.
  • I believe his car is a 1989 740 turbo which will have LH 2.2
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    I believe his car is a 1989 740 turbo which will have LH 2.2
    That's normally true for an '89 740T, but OPs wagon is actually my old wagon and I converted it to 2.4 back around 2011.

    I'm not sure what car @GingerNinja is asking about, so here's a more generic procedure if you can't run the injectors in diagnostic mode.

    Pull the injectors and rail and put a small bottle over each injector, disconnect the coil (so that you don't generate lots of high-voltage sparks around open fuel sources), then crank the motor and watch the spray pattern from each injector. If you want to be even more scientific, you can weigh each bottle before testing and after, and the weight difference should be the same (indicating fuel flow is consistent across all four injectors).

    7lAauIvh.png
    JamesM
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