So a few weeks ago I did a compression test on my 2010 GSR just to verify it's internal integrity. I did some research on how-to before I did the procedure, pretty simple so I gave it a go.

First I ran the car around my block a bit to get it warmed up then I took it to my driveway. THere I parked it, removed each coil pack pigtail, each coil pack, each spark plug, and the Inj. PTC relay.

I performed the test once without WOT and results came up fine (150 psi across the board, plus/minus 1psi). So I buttoned up everything and went for a drive. *Immediately* I noticed itd miss when I applied load after letting the clutch go into first or second gear, or anything like 25-30% throttle around 3krpm.

I didnt think anything of it. So I just went home, and read up on here about my results, someone sugested I redo the test whilst holding the throttle WOT. SO i did... removed the same stuff, got the same results. Put it all back together and drove it around. Still missing randomly (no CEL tho) and I didnt think anything of it.

The issue finally surfaced more prominently when I tried to do WOT pulls.... it completely falls over itsself at about 3100rpm. Misfiring.

So Idk what I couldve done when I did my compression test, but im about 90%-95% sure that something I did then had messed something up....

-Checked frp hose
-checked plug condition and gap
-checked fic1100 injectors (swapped back to stock, same issue)
-checked fuses and relays underhood

i really dont know what else to check/do. could something mechanically gotten ffed up when I cranked the engine over during the compression test? like the chain, or sensors or something?

gimme some more ideas, i'm at a dead end :/

thanks

-Steve

 

Disconnect and inspect every connector that you touched, checking each one for broken contacts and/or debris. My money is on one of the coil-pack connectors being an open circuit, but check them all.

 

I will go and do that, thanks for the reply

although, wouldnt that yield a misfire code for a specific cylinder/car not running well at all?

it drives around the town great

but, nonetheless, ill go clean all the connectors and check em out (again lol)

 

If the issues mostly surface when going WOT then it's possible your plugs are having issues. Check that the gap is around .022" and verify that they are in good shape. Seems odd that the compression test would trigger these issues but another possibility is that something in your ignition system is shorting out somewhere.

 

This was what I was thinking. A partially connected wire is enough to fire when not in boost (only).

 

all plugs are at 0.022"

hmm... interesting, well I'll triple check all the pigtail connections

 

Make sure your plug wires are going to the right cylinder... I had this problem on an old GSX of mine and it was because swapped #3 and #4 cylinder plug wires...

 

...there are no plug wires

 

Ever figure this out.... caught my interest.

 

sadly, no I'm literally at a dead end. if the plugs don't fix it (they should be arriving on Friday) then I'm bringing her to SpeedCircuit

 

Did you ever find out what your issue was?