onefast ls1

Recently just put on a z06 intake and headers no tune, I have a oring leak on fuel rail right by cylinder8 in which I have encountered a misfire in. Car was running 13.7 now runs 14.7 is this a common problem running untuned? And am I hurting the car by running untuned? And I was also told most cars that throws a misfire in cylinder 8 is normally on its last leg !!! Need help

Bowtie316

iTrader: (1)

Need more information.

What did you put the intake and tune on?

What o-ring is leaking, injector to manifold? Vacuum leak?

Car was running 13.7 when? during wide open throttle? And how are you measuring it?

onefast ls1

The intake is on a 99z28 and no tune at all.
The oring injector to mani.
And the car ran 13.7 before I added intake and headers wot at track. With headers and intake untuned 14.7 wot

Bowtie316

iTrader: (1)

How are you measuring afr? Wait are 13.7 and 14.7 track times or air fuel ratio???????

If those are track times, I think you might have an injector (#8 likely) unplugged or malfunctioning. Does the car run clean and smooth?

I don't think people usually slow down when adding intake and headers, but they won't gain much without a tune. I suspect something is wrong at this point.

You must get the intake leak fixed before going any further.

onefast ls1

Oh sorry about that it's track time 1/4. Okay thanks for the help also

Bowtie316

iTrader: (1)

Yeah, I was confused, I edited my post to relate to track times.

With a vacuum leak, the computer will have to add fuel trims to compensate and is probably dumping a lot of extra fuel during wide open throttle because of it. Also, need to figure out the cause of the misfire and get it fixed.

onefast ls1

Ok I'll be working on it. And one more question have u ever hear of ls1 motors throwing cylinder 8 misfire right before engine failure? That's what I was told by someone

The car runs pretty decent overall. But a few nights ago I got the p0300 code and it had starting missing bad but I haven't really driven it since

Bowtie316

iTrader: (1)

I have never heard of that, but there are lots of things I have never heard of.

onefast ls1

I found the problem and fixed it. Person who installed my intake put my injector oring in at an angle and that caused it to leak out. Car now feels a little better. Thx for your help