Ok, to start off here's what is on the car:

-LE 1 heads (flow 262/183)

-Speed Inc. LT1 ported intake with 58mm throttle bores

-LE 1 cam (224/224 .573/.566 108LSA with 1.6 rockers) ...this cam was ground a year ago and setup for what I wanted, so it's prolly not anywhere near the same as anything lloyd's making now for a basic LE 1 cam.

-ARP head bolts

-Comp 7/16 rocker arm studs

-ARP polylocs

-Comp 5/16 flat pushrod style guideplates

- NGK TR6 plugs

-COMP chromoly pushrods

-CSR Electric waterpump

-3600 Vigilante converter

-3.73 gears, on 10 bolt

-Transgo Shift kit

-hypertech 160 degree termostat

-groty 1 3/4 long tube headers

-BBK 58 mm TB

-1.6 Comp pro mag 7/16 Rocker arms

-SVO 42 lb/hr injectors

-Cold Fusion Nitrous kit (150 wet Shot)

-MSD window switch

-Cold Fusion fuel pressure safety switch

-walbro 255 fuel pump

-B&M trans cooler

-MSD ignition Coil

-UMI Lower Control Arms

-UMI panhard bar

-Moroso cold air intake

-BFG drag radials

-Clevite H main bearings

-Clevite H rod bearings

-Clevite cam bearings

-ARP main bolts

-Total Seal file to fit, ductile iron piston rings

-Moroso high volume oil pump

-GM Tall, polished valve covers

Here's a little background information:

Ever since I my motor refreshed and threw on a heads/cam package I haven't been able to get this car running right. The problem for the longest time was that it runs extremely extremely rich (the plugs foul out after every run and it drops a LOT of gas into the oil pan in a couple mins of run time.)

So far here's what I have looked at:

-The tuning was done 3 times on 2 different chips by Ion, the tuning is done for 42# SVO injectors, I swapped the stock 22# injectors back in and it would still runs rich enough to foul out all the plugs after every run. Also the injectors are NOT leaking and when the car is off (there is no fuel dripping through them into the cylinder.)...

-The injector duty cycle was close to 10-15% at idle!!

-It is set to run in open loop and the O2s are removed, the EGR, Canbon Canister, and the AIR pump are also removed and the codes for them are deleted, but all the sensors that are still hooked up are working perfectly (I checked a few of them with the multimeter and ALL of them through datamaster DA.)

-I ran a compression test and all the cylinders make very good compression and the highest to lowest cylinders are at a 6-7% variance. (the motor has only been run for the cam break in and then for a few minutes here and there and thats it.)

-I just double checked the valve timing and it was dead on with the cam and crank gear.

-I also just double check the Opti and it was installed properly and was reinstalled properly (the missing tooth on the opti rotor and cam gear and lined up with the missing gear on the splined shaft.)

-I check ALL the valve lashes and when every valve is closed the pushrod can spin by hand, which would not be possible if the it was adjusted to tight and the valve was sticking open.

-All the vaccuum hoses are hooked up.

-I just started up the engine again with this warmer weather it appears to warm up right away and there is literally no backfiring (it is really apparent when it backfires at all through the open headers.) and it appears to run just fine and also drives fine (I drove it down the block and back around), minus all the smog all the unburned gas running through it.. (ON MY 3RD TUNE)

-Fuel pressure sits at 39PSI with the vaccuum line attached.

-The one thing I did notice is that the thing literally makes near no vacuum at lower RPM's.. It's hard to tell because it won't idle by itself at all, but to try and compensate for the next to no vacuum I had Ion retune (4th tune) to lean out 60% on the tables at lower rpms. Now with the stock 22# injectors in there is no smell of fuel at all even with the open headers.. it actually smells cleaner than it was with stock a stock cam in closed loop (didn't have a catalytic converter on at that time either tho). So if anything it is running a little lean now on the 22# injectors, which it should be..

BUT the problem now is that with the next to no vacuum the ECM has no way of knowing how much air is entering in through the throttle body, so as of right now if I keep the throttle stop screw completely closed and keep snapping the thottle open, it will keep running but if I try to crack the throttle blades a bit with the stop screw and/or holding the thottle open constantly it won't put in enough fuel to keep it running... Even if I hold the throttle at 40% at 800-900 rpms it just dies out.

I am really thinking that this problem is a bad leak at the intake somewhere, because when I went to unplug the IAC before messing with the stop screw I pulled off the PCV hose the hose right below that on the throttle body I forgot to put them back on and fired up the car and took a datalog and then I realized I forgot this after a few seconds and went out and hooked them back up and took another datalog and it appeared to have made a very small if any difference in vacuum whether or not these very large hoses were hooked up or not, which should have caused I pretty big difference in vacuum.

So my question is, in my case, where the car won't even idle by itself, how can I find this intake leak?..
Would it be possible to just unplug all the vacuum hoses that hook up to the intake manifold and plug them up somehow (if so, what to plug them up with?) and then try to breifly run the car to see if that makes a differene in vacuum??..
Cuz if I could do that it would atleast narrow down the possibilities of a leak to one of three things, a leak at the manifold between the heads and intake ports (would probably have to be a very small leak there for it too stay running as long as it can) or it would be at where the AIR or EGR is blocked off..

Also here are some datalogs of the car.. maybe someone can see something else also wrong with the car?

This is one on 3RD tune where it was dumping in so much fuel it would foul out all the plugs after every run and dump 3 quarts of fuel into the oil pan in just a couple minutes of running it:
http://www.yourfilehost.com/media.ph...e=datalog8.uni

Here it is again in .csv format:
http://www.yourfilehost.com/media.ph...47datalog8.csv

Here is a log when I forgot to re-hook up the 2 vacuum lines that go to the throttle body and had the thottle blades cracked open to 1.18V (4TH tune, leaned out 60% at lower rpms):
http://www.yourfilehost.com/media.ph...g11_novac_.uni

And once again in .csv format:
http://www.yourfilehost.com/media.ph...g11_novac_.csv

Here is one on the 4TH tune with those to vacuum lines on the thottle body hooked up, still held at 1.18V on the thottle blades (as you can see it didn't make too much of a difference):
http://www.yourfilehost.com/media.ph...=datalog12.uni

And once again in .csv format:
http://www.yourfilehost.com/media.ph...=datalog12.csv

And lastly, one more with the 4TH tune, the vacuum lines to the thottle body still hooked up and the thottle blades fully closed:
http://www.yourfilehost.com/media.ph...e=datalog9.uni

And in .csv format:
http://www.yourfilehost.com/media.ph...39datalog9.csv

 

Sounds like an intake gasket leak or the rockers are as little too tight. I didn't read it all though. That's too many words on a Sunday to read.

 

Haha yea that is a lot to read I am going to agree with whitehooptie on the intake gasket leak !! Keep us informed bro

 

I would recommend using starting fluid, but it's going to be hard to tell since it won't idle. If you can get it to smoothly run by itself at all (even at a higher rpm), you could use the starting fluid method. If it was an internal intake gasket leak I would believe you would have oil on the plugs.

 

lol

I was looking at it and the intake is sealed so well with RTV, so I don't quite want to jump ahead to pulling the intake off yet, but I was thinking that this might be a possibility as well.

 

Yeah, I kinda wish it would idle by itself at all so that I could try that starting fluid idea. I dunno, I was talking to my buddy yesterday tho and we were thinking, what if I were to just sit there and fiddle with the gas to keep it running and then he could just sit under there and smoke a cigarette and just puff out the smoke at the intake to see if it starts sucking in the smoke somewhere, only thing that wouldn't really easy to see would be in the back there were the block off plates for the AIR and EGR are.

I guess these next few questions were the reason for posting, just kind of threw in a bit of background information so I someone doesn't suggest something that I already checked a few times as a potential cause for my low vacuum. I was kindof wondering if there is a way to pull out all the vacuum hoses and blocking off all the nipples at the intake manifold (anybody got an idea of what to use to do this?) and then trying to start it and see if it makes vacuum to see whether the leak is actually at a gasket/block off plate OR at an actual vacuum line.. Can I do this, would I be able to start it with all the vacuum lines disconnected and the manifold nipples blocked off?

 

Why do you have RTV on the intake gasket? Isn't it a crush gasket?

Yes you can pull them all off. Keep the regulator one hooked up though.

 

Also try pulling the brake booster line out of the booster and plug it off with you hand. I haven't seen it happen but maybe something to check.

 

If ya got THAT bad of a vacuum leak it would not run unless ya had it very very rich.

Yes ya could start it with them all blocked off.

 

One way I have used to find a intake gasket leak is to back off all the rockers so the valves are closed. Take off the TB and use a rag around the air hose nozzle and blow in the intake. Ya will hear air coming out of the valve covers if the gaskets are leaking.

 

Yeah, its not so bad that it won't run.. I'm guessing it is around 6-7" hg of vacuum (at best) at where it would idle if it did that... so with the thottle blades cracked open to allow it to idle its probably more around 3-4" hg vacuum (at best). Lloyd was saying with the cam I got it should make 12-14" hg of vacuum at 900 rpm with everything "Dead on" including the tuning.. I really wouldn't even care about this but this tuning with speed density is apparenlty a nightmare without enough vacuum being it really has no way of knowing how much air is coming besides guessing based on the MAP sensor.

 

cool... i'll have to try and see if I can't get someone to let me borrow their air compressor to try this if the leak doesn't end up being at some hose(s).

 

it's a felpro intake gasket.. pretty sure its not a crush gasket, cuz I recall the gaskets coming with a small tube of sealant

OK, so how exactly do I go about blocking off all the nipples on the manifold then? What can I use to do this? A few layers of duck tape (lol)?

 

[QUOTE=93camaroLT1]it's a felpro intake gasket.. pretty sure its not a crush gasket, cuz I recall the gaskets coming with a small tube of sealant



OK, so how exactly do I go about blocking off all the nipples on the manifold then? What can I use to do this? A few layers of duck tape (lol)?[/QUOTE



Tape over the ends or the parts store has rubber caps in an assortment of different sizes ya could get.
Ya are NOT dealing with that much vacuum so just press some tape over the ends of each outlet and make sure it seals.

 

I used duct tape and it worked fine. Just make sure it is pinched or folded over and it will seal.

You shouldn't have to worry about the car running too lean at idle, because in the tuning tables, with that high of a MAP at idle, the car should run rich. Basically, it thinks there is a load on the car at idle and SHOULD feed it more fuel.

I would say adjust the throttle body blades open some and see if you can't get it at a high idle. If you could do this, you could test using the starting fluid method. If not, then loosen all of the valves and use racerdude1's method, which is very clever btw.