Sooo I've had a few random misfires over the past few weeks under full boost, checked/changed plugs, no change in problems. Well last night I was taking a buddy home, around 40mph in 2nd I got on her, not hard just moving around traffic, and she missed like a ****, enough to flash the CEL numerous times, I quickly got off the Go pedal, let things settle and tried again to see if it would happen, well I couldn't get over 7lbs of boost without major issues.

I got home and checked everything out, did a compression test, numbers were golden across the board, also when I scanned my CEL I got misfire detected, and misfire cyl 4.

Popped the valve cover off and found to loose rockers, on the exhaust side of cyl 3, so not the issue but getting replaced.

My next shot after doing some reading is the seal for #4 injector, Got the mani out the way, Got the rail off the car, but injectors still in the head, how do I get them out, Just pull I assume but I want to make sure before I mess something up.

-Alex

 

PM chevycobaltss3(James), monograt, or IamBroke(Tom). They know for sure.

 

You have to unbolt the fuel rail and unhook the fuel inne and they just pull out.

 

Cool thx guys I got them out 4 had carbon baked all over the tip, I cleaned it up, swapped with 1 and now I just need to button her up, either it will fix it or migrate to cyl 1

 

Did you put in new seals? You have to replace them every time you pull the injectors.

 

I have a seal kit on order, I figured I'd jump the gun a lil the car isn't even drivable, well all said and done, 4 still misfires hard as hell at idle and any kind of gas and it sounds like a subie.

I did another compression check and everything comes out good, at idle I am running super lean

-alex

 

Swap coil packs and if it still doesn't move, swap plugs. You WILL need new inj seals though.

 

^x2

 

Already did that, I've swaped Coils, Plugs, Inj, Compression test (checked good), and cyl 4 still misfires bad as ****, I've made sure she is getting spark and fuel, but the car sounds like a a subie.

At idle i see 14.8-15.01 AFR if I blip the gas it goes into subie mode and my AFR goes to 18+ at idle, give it a lil gas and she goes to 10- the entire time sounding like a subie. If I drive it it misfires no mater what!

I'm at a complete loss as to what to do or what is going on...

-Alex

 

How many miles on the car?

A few other things you could try is the universal fix, disconnect battery and hold terminals together to reset everything, seafoam the car if its never been done, and do a running compression test since it passes the static Comp. test

 

I'm sitting at 40k, Ill try the battery trick, either that or I'm gonna torch the car

 

The subie sound still makes it sound like your having a lifter/lash adjuster issue. Did you replace the cylinder 4 lash adjusters/lifters?

 

You may have to do a leak down test.

 

4 and 3 have new adjusters, the misfire is out of 4 now, but 2,3 and are missing horridly now

-Alex

 

did you check the spark plugs? just sayin..

whats the gaps?

 

In the end there were a few problems. He had two broken cam followers. Replaced them. Better. Still not right.

Changed his coil packs around. The misfire moved. Grabbed one out of my car, put it in his. Fixed. Got a new one from the dealer. Replaced mine. Took his car for a ride. Damnit! It started misfiring again. Getting worse and worse. Mind you this thing never threw a CEL other than misfire through the whole deal, until just as he got it home when it finally said cam position sensor.

Got it in the garage again and it sounds like something is rattling under the valve cover. This ain't good.

Got the valve cover off and nope it wasn't good. the left hand cam retainer had a broken bolt and the other was lose. (the lose one was popping up and hitting the underside of the valve cover) The next one to the left? Same thing. The cam was actually floating around.

Luckily for him one of the bolts broke was sticking out of the block and came out with needlenose pliers. The other one was broke off IN the head. This didn't look good at all. Son of a gun though, he stuck a tiny skinny screw driver in the hole and actually turned the remaining piece right out of the block. So lucky!

Bolted it back together with some spare cam retainer bolts (or whatever they're really called), torqued it up to spec, reassembled the car and it's now purring nice and smooth again.

Totally frustrating day but it ended ok.

Oh, he did all the work. I just watched and drank coffee. I'm exhausted!

 

ya im glad we finally figured it out, i drove his car and it was horrid, even driving behind him the car sounded shitty. we literally took it all apart and put it back together. But glad we got it fixed!

 

I'm still tired from watching you guys work. I need a nap.

 

Was this a result of forgetting to tighten the bolts after installing lash adjusters/rockers?

 

That seems to be the conclusion we all reached, yes.

 

Well, I'm sure glad you guys got it fixed. Congrats!

 

How did the car idle when you had this issue?