XtremeDime

iTrader: (16)

I got it, its just a matter of when I can get out there to help him out.

-Q-

iTrader: (10)

I appreciate that. Ak95TA also offered to bring his HPT over to run some logs, so hopefully between us all we can get it fixed up.

I got an email back from Steve, and he says the values I posted up from the engine at idle are great. Everything is as it should be. So somewhere after the point that I begin to apply throttle is where something is going haywire...

-Q-

iTrader: (10)

Got an update. Ak95TA came out last night and was kind enough to take some logs for me to send to Steve at Frost. Steve quickly replied, and is certain there is a vacuum leak somewhere. Idle air is trimming an "insane" -20g/sec, and there is still multiple misfires.

So I guess its back to the drawing board. I'm going to disconnect my entire PCV/catch can setup and plug all the ports for starters, and see if its something there. Then I guess I'll turn my attention to the brake booster hose where I'm tee'd off for the gauge and bypass valve, and possibly pull the injectors back out and reinstall those as well.

This **** is going to be the end of me...

-Q-

iTrader: (10)

Still no luck. Disconnected and capped the entire PCV system...no luck. Pulled the rails and injectors and re-seated everything...no luck. Checked all the brake booster hoses and tees....no luck.

Get out the gasoline and matches...

chevybowtie

iTrader: (16)

Any sensors that may not have seated right that could cause a vacuum leak? Maybe the oring on one of the sensors has been pinched..... This would cause a leak that would be really-really hard to detect.

XtremeDime

iTrader: (16)

I feel your pain. Come over tomorrow, maybe my POS will make you feel better.

-Q-

iTrader: (10)

I get off at noon...I'll give you a call around then.

Not that I can think of. The only one I fooled with at all was the IAC, and I just swapped in my old throttle body to see if that was the issue, and got the same results.

XtremeDime

iTrader: (16)

Sounds good man, Im gonna start working on it around then too. I checked your IAT sensor when I was over there too, lol.

chevybowtie

iTrader: (16)

At this point I would highly suggest taking off the intake. I know it sounds stupid but it may at this point help alot to find the leak. It's somewhere on that intake...... Maybe the nipple in the back. I heard people cracking or breaking them.

ak95ta

iTrader: (3)

What time is everybody showing up over there?

Here is -Q-'s log we did if anybody else wants to take a peek

odarabla

iTrader: (1)

+1 on the intake.

AFASTYZFR1

iTrader: (55)

Check intake and maybe re-do all the vac lines just to be sure. I'm about to have to do the same thing because of a fuel system problem, but this car runs fine in speed density even if there is a vac leak.

https://ls1tech.com/forums/forced-in...c-build-6.html

-Q-

iTrader: (10)

Well, I set the car on fire last night. Insurance adjuster is coming by today...hope I can get away with this...

Only kidding. I am really hesitant to pull the intake, only because it has been my experience (meaning "my luck") that doing it would probably cause more problems than I have now. I could see me pulling the intake, breaking the oil pressure sending unit, and creating an additional vacuum leak all at the same time...and probably not finding the one I have now...

I am going to pull my triple pod pillar down and check the back of the boost gauge to be sure that line isn't loose or off, and then check all the hoses one last time by hand before I consider pulling the intake. I'm suspicious of that other small hard line on the back of the intake for the HVAC...the one with the little filter or valve on it? Don't know how I could go about troubleshooting that one...

-Q-

iTrader: (10)

Still no luck. I hate this car. Checked all vacuum hoses AGAIN, brake booster tee again, pulled the pillar pod and checked the boost line, even sprayed some more carb cleaner...nothing. I am starting to wonder if there is anything else that could give me these symptoms.

When I start the car, the idle is perfect. Really smooth, about 900rpm. As it warms up, the idle falls to about 750-800rpms, and begins to get a little rough. By the time its at operating temp, I can hear a slight surge at idle...but only like 50rpms or so. It's barely detectable.

As soon as you crack that TB, all bets are off. Hesitation, followed by the rpms coming up to match the throttle position. Tonight it held rpms at 1500rpm for a good 8-10 seconds before it started surging. Then it surges like 300 rpms, down and back up.

I really do not want to pull the intake, but I don't know what else to do. I borrowed a lighted scope so I could look at all the connections on the back of the intake, and everything is plugged in and looks as it should. Really starting to think there must be something other than a vacuum leak that could cause this...

AFASTYZFR1

iTrader: (55)

Pulling the intake is a piece of cake, maybe it is cracked....?

WS6Drop

iTrader: (10)

I know under boost my MAP sensor in the back of the intake popped off and then I had a big vaccum leak. This was on a fast 90, but it would be something I would check even if you have the stock intake.

AFASTYZFR1

iTrader: (55)

I have never had an issue breaking oil sending unit, I don't know what everyone does to do that but just be gentle......I have had my intake off more times than I care to remember and I have had a Fast 90mm, Fast 92mm, and a ls6

I really think you need to check it out Just be careful

-Q-

iTrader: (10)

I just don't understand how an intake can crack itself. I've never had the thing off, never fooled with anything around it except the TB. The car is pulled into the garage last fall, runs like a top...now I put a procharger setup on, and it's cracked over the winter?

I'll probably pull the damn thing off....

Frozen WS6

Q. You could have called me. I have efilive and a tech 2. Also I'm just up the street. Definately listen to Dustin. He knows his ****!!

-Q-

iTrader: (10)

Bro, I'd be happy to have you take a look. If its a vacuum leak, I can't find it.