Comp testing a V6

[losh1971]

Umm my way bypasses all the stuffing around. You give the starter power it spins the engine and the ECU has no power so not input to the DFI or the injectors.
All you have to do is pull the starter relay get a paperclip and jump the relay.

What about just pulling the engine fuse? Also if you have a wire bridging the starter relay, how can you hold it WOT at the same time?

 

[shane_3800]

What about just pulling the engine fuse? Also if you have a wire bridging the starter relay, how can you hold it WOT at the same time?

You don't need to. But just grab the throttlebody and open the butterfly.
I've tested WOT vs no throttle on the test all it does is get to the same reading one rev quicker thats about it.

 

[losh1971]

Think it will be easier to just pull a few things and then use the pedal and key. I will need a second person if I try it your way.

 

[shane_3800]

Think it will be easier to just pull a few things and then use the pedal and key. I will need a second person if I try it your way.

No you don't. Try it my way without touching the pedal the do a test WOT just let them botb pump up to max it will only take 5 cycles max. Then report back if there was a difference.

 

[EYY]

Could always just hold foot flat on pedal anyway. Pcm will enter clear flood mode and won’t fire injectors lol

And yes, as immortality said, the oil pressure switch works as a backup in the event of a relay failure. I also learned that the hard way.

 

[shane_3800]

Could always just hold foot flat on pedal anyway. Pcm will enter clear flood mode and won’t fire injectors lol

And yes, as immortality said, the oil pressure switch works as a backup in the event of a relay failure. I also learned that the hard way.

Hence why again if you just jump the start relay nothing happens.

 

[losh1971]

So it turns out a Buick has a deeper hole than some, and my comp tester being a 2 size plug hole one, won't go in deep enough to grab the threads in the head..... Spewin, because I just pulled all the plugs and the DFI plug.....

 

[woteva]

So it turns out a Buick has a deeper hole than some, and my comp tester being a 2 size plug hole one, won't go in deep enough to grab the threads in the head..

Had the same problem years ago when comp testing a misfiring engine and it was a sticky valve.
I made an adaptor from I think it was M14 high tensile all thread with a hole drilled through it and a M14 nut welded on the other end. Not sure where it is now because I haven't needed it for over 10 years.

 

[losh1971]

Had the same problem years ago when comp testing a misfiring engine and it was a sticky valve.
I made an adaptor from I think it was M14 high tensile all thread with a hole drilled through it and a M14 nut welded on the other end. Not sure where it is now because I haven't needed it for over 10 years.

I have now have two choices grind down my fitting or put it back together and pay to have it done. Replacement comp tester is about 80 bucks. Considering I haven't used it in years i am considering getting on the bench grinder....

 

[Lex]

I have now have two choices grind down my fitting or put it back together and pay to have it done. Replacement comp tester is about 80 bucks. Considering I haven't used it in years i am considering getting on the bench grinder....

You can buy compression tester extenders.
ex.https://www.aircraft-tool.com/shop/detail.aspx?id=E14MM-XT
Might be able to get one local, cheap?