6.2L MPI compression test help

[johndoe]

preparing to buy 2004 Regal 2665 Commodore with 100 hours on 6.2L MPI 300 HP, and having the survey done this weekend. ($400.00)<br />not sure why the surveyor won't do compression test, but he reccomended I have the shop do it. The shop wants $200.00 to perform a compression test. I have a $60.00 Craftsman compression test kit that I have used before... on an old chvy 350.<br /><br />How hard is it to do this myself on a marine engine with fuel injection? I have a remote starter button but afraid of causing a problem when hooking it up to crank the engine... Is this the correct way to do it in order to avoid the fuel being injected during the test? Since I do not yet have any manuals for it, I thought I better check with a reliable source... any tips or thoughts would be appreciated.<br />thanks

 

[ron7000]

Re: 6.2L MPI compression test help

not hard at all, the only difference here is you want to disable the fuel pump and fuel injectors, both of which are electric. You don't want to be shooting fuel into the cylinders when it's cranking. You can probably do this by pulling a fuse from the fuse panel. I'm not familiar with the motor, so someone here may be able to post the specifics of how to do that if there's a better way.<br /><br />Other than that, you'll also want to disable the ignition coil (fuse probably), remove all spark plugs, put throttle wide open to open throttle body flap or manually prop it open. You can use a remote starter if it's easy to attach but I find it just as easy if not easier to lay the tester down in the bilge and just crank the engine via the key on the dash.

 

[johndoe]

Re: 6.2L MPI compression test help

thanks ron...<br /><br />anyone know if this can be done by simply upplugging the leads to the fuel pump and/or injectors? is there an easier way.. since its not my boat yet, I want to be sure I don't harm anything...

 

[rodbolt]

Re: 6.2L MPI compression test help

and thats why the surveyor wont do it either, that 200 buckswill be the best or worst ya spent but spend it.<br /> if the tech is good he will hunt for you. most techs I knoe get very thoughrouh when they have to sign the workorder. but dont just ask for a compression test or thats all you may get, ask for a mechanical survey.

 

[Don S]

Re: 6.2L MPI compression test help

And just think, if you screw something up, you have to fix it and it won't even be your boat.<br />Personally, if I was selling a boat, I wouldn't want every perspective buyer that came along taking things apart and doing things they aren't qualified to do.<br />A 6.2MPI is a long way from that old Chevy 350 you are talking about.

 

[johndoe]

Re: 6.2L MPI compression test help

good point rodbolt. I think i talked to you sometime ago and you helped me order some parts for my 1966 Chrysler... I went back looking for you and you were no where to be found. <br />Doesn't matter anymore, I sold that boat...<br /><br />On a 2004 6.2L with 100 hours I don't expect many problems... it is a very clean and well cared for boat. the owner got transferred from WA state to TX and doesn't have a trailer or a means of towing it down there, so eager to sell.<br /><br />Compression test seems easy in my head, I am mechaninc and been around boats a long time, just never done a 6.2L or a fuel injected engine... <br />You think paying another guy to do it is smart investment...? probably less work for me, but I feel capable and like to save money...<br />hmmmmmmmmmmmmmm