Top end issues!

[Jaxon]

those turbo adapter plates for stock manifold suck. Seem to cause quite a bit of surge and spool late. A local here has a little larger turbo that has an adapter plate and it surges a little bit and doesn't spool as quick as a s252 with a zzp manifold even though it has a smaller turbo that SHOULD spool up quicker.

[1080112520]

if i can find someone with a k04 id be glad to trade but id need some cash as well lol....... but i dunno

[Jaxon]

You can get a custom turbo header made for a decent price. Try treadstone iirc.

[BackyardTurbo_FTW]

GMTech feels its valve spring related. So if the injectors don't cure anything, its time to dive into the head.

[1080112520]

hmmmm john did replace the lash adjusters and mkreibs is the one that did the work, i wonder if they fudged somthing up

[Iam Broke]

Nick was talking about his own car, no need to trash anyone on here. With everyone that's had their hands on that vehicle of yours , it would be a very long list to start pointing fingers.

Everyone that has tried to fix it was trying to help. Many tuners here were helping any way they could on the first iteration of the beast.

[1080112520]

^^^ I wasnt buddy calm down bro i said this " john had the lash adjusters replaced by mkreibs" so in doing so i wonder if either they didnt replace one, or screwed with the wrong thing. who knows, never pointed fingers so yourself needs to take your own statment into consideration.. And nick is haveing the same issue as i am so im hoping either him or i fix the issue with our car, ive did compression tests, leak down tests, replaced parts tested parts changed my tune, and relogged, nothing there.

thanks

[Iam Broke]

hmmmm john did replace the lash adjusters and mkreibs is the one that did the work, i wonder if they fudged somthing up

"I wonder if they fudged something up" sounds like blaming Matt to me, sorry if I read your bad choice of words in error. No harm, no foul.

[1080112520]

its cool bro..... all i know is when i bought the car john said matt worked on it. i asked john did the car wack out at 6k he said no just the normal surge sound and now since i got the car its all crappy lol. trying to figure stuff out when 10000000000000 worked on it suks lol.. im a diag tech and a itt guru and i still cant figure it out, ive yet to look at the head so i will look thanks nick for giving me a idea lol

[Iam Broke]

I had a missing injector seal on mine on #3 for ~50k miles from the factory, it didn't let go until one night during a pull. After that I couldn't boost above 0" without misfires and popcorn. Pulled the injectors & rail off and the seal was never there. No scraps, no pieces, nothing in the cyl, just carbon in the relief where the teflon seal should have been. Tight enough mech fit to run ok for a long time, compression was always ~10# lower on #3 and couldn't find out why until then. There are some strange things with these engines. Now comp is 165-167 on all 4. Much luck! Hope you sort it out.

[1080112520]

yeah i hope i find it soon if not i see the car in a big da** lake lol saying please fish me out james ill fix myself lol.. i only get kr or a misire on number 3 or 4 never anything else. the lash adjuster that was replaced was on 4, i wonder hmmm possible a bad Valve spring....

[1080112520]

hey nick btw i dont remember if i told you wut my issue was. One of the lash adjusters were cracked........ reason for the top end issue

[silverbullet08]

Still fighting this crap. I tried another set of new plugs without gapping them at all thinking that may have cause an issue somehow, no change tho. I did notice when Im below 10% ETC Pedal the trims kinda sine wave and you can feel the car doing something weird. Im thinking maybe vac leak?

Im going to try gapping my plugs down to .028 and see if that helps at all, finally rule out ignition then too.

I loaded a tune now that's 23-24 psi in the low/mid range, then tapers off hard up top with a mess of timing. Car actually runs pretty damn good and is still fun

I know what your talking about with your fuel trims waving. Mine did it when i had a coil pack go out. it would idle fine then every 3 or 4 secs it would misfire once or twice and STFTs would go from about +3 to -6 with a staedy flow. But whats different is that mine would only misfire under massive load. it got worse and worse over time but if i eased into the throttle slowly to WOT i could actually make a whole pull with out it misfiring. gas milage went down a couple mpgs aswell. I figured it out by just putting it on a tech 2 and logging each individual cylinder for misfires. It showed a steady missfire under load only on cyl 2 so i swapped packs and bam it moved. its either going to be a coil pack or injector if your compression is good and holding on a leak down test. a car i recently tuned with 15k miles had a clogged injector showing the same signs. after gm took it apart they ended up replacing two injectors and had the head redone due to massive engine carbon on the valves and combustion chamber. How did you do your seafoaming?

[T-Man]

Nice to hear that you got things fixed SB. I'd assume the seafoam would be pulled in through a vacuum source, such as the break booster line? I'm curious to know how Nick did it as well. I've always used the BB line but ya never know with this damned LNF...

[Iam Broke]

I use a .030 welding tip in a piece of 1/4" hose attached to the intake mani port next to the purge sol. It's the vac source for the acc tank vac for the boost sol/wg control. The tip limits the vac leak and I let it slurp up the seafoam & some air at idle, let it sit 5-10 mins and blow it out on the road (at night to hide the cloud). Do it warm engine.

[T-Man]

Thanks IAB

[DoMiStIc_RuSh_06]

so what would be the signs of a front o2 sensor going out?

[1080112520]

check the sensor for meltage, carbon build up, ect, if you wanna know by reading from the gauge the scale of voltage wont change alot or quickly, itll stay at one point most of the time either saying lean or rich or in between but it doesnt fluctuate as much.

[silverbullet08]

Nice to hear that you got things fixed SB. I'd assume the seafoam would be pulled in through a vacuum source, such as the break booster line? I'm curious to know how Nick did it as well. I've always used the BB line but ya never know with this damned LNF...

Yea i used the brake booster line. I am still getting a wierd missfire randomly... it usually does it bad the first time i get on it for the day then misfires once or twice second pull then none the third... On a log everything looks completly normal except for a couple degrees of kr when it misses... im still looking into it.

[MiamiFan4Sho]

Any luck with this thread?