How do you check for vacuum leaks? (code 44 AGAIN!)

[d0n_3d]

Originally posted by BobbyBuick
YES,the computer is adding fuel and adding at a rate that you still get no cross counts .if you go off idle and it gets cross counts you need to look for a vacume leak .have you checked your pcv valve like i posted twice.if you have than look for another vacume leak.obviously the upper plenum needs fixed and can be the culprit.have you plugged the pcv valve yet?

yes i have tried all of the above with the pcv valve...that is not the issue...i also added the inline check valve i have for it...still the same...took it off...still the same...plugged it...still the same...

i am thinking it's the plenum...we'll see...thanks for the help though

 

[JayLashua]

look
CHASING THE WRONG PROBLEMS.

wha tabout your ECM harness?

there is obviously NO SIGNAL !!!

22 mv, no cross counts.. come on..

get a volt meter, or continuity tester.

on gnttype there is an ECM pinout
like D4 and D5 or something like that are the o2 leads (im not exactly sure)

test them both for continuity ..

make sure none of the wires got pushed out of the wire harness (happens sometimes, if youve ever taken it apart for some reason)

finally, the ground for the o2 sensor should be attached to a bolt which goes to the head.

this definitely seems liek an electrical problem..

I blew the bolt out of my turbo braket and had a HUGE vac leak from that, and all that ever did was make it a pain to take off from a red light.. and make a loud noise in boost ;P

ok? check the damn wires you're going to stress yourself out over this vac leak crap!!

just my $.02!

 

[Eric Stage I]

With no connection to the o2 sensor, you would see a constant voltage of about .400.

 

[QuickWE4]

Probably not the plenum - most of us who have had the plenum off are running around with a stripped pass side bolt. If the others are holding, it's probably not leaking at the plenum.

But if you need to helicoil it, get the kit for an 8mmX1.25 bolt. I did mine last time I had the plenum on.

Rich

 

[d0n_3d]

Originally posted by JayLashua
look
CHASING THE WRONG PROBLEMS.

wha tabout your ECM harness?

there is obviously NO SIGNAL !!!

22 mv, no cross counts.. come on..

get a volt meter, or continuity tester.

on gnttype there is an ECM pinout
like D4 and D5 or something like that are the o2 leads (im not exactly sure)

test them both for continuity ..

make sure none of the wires got pushed out of the wire harness (happens sometimes, if youve ever taken it apart for some reason)

finally, the ground for the o2 sensor should be attached to a bolt which goes to the head.

this definitely seems liek an electrical problem..

I blew the bolt out of my turbo braket and had a HUGE vac leak from that, and all that ever did was make it a pain to take off from a red light.. and make a loud noise in boost ;P

ok? check the damn wires you're going to stress yourself out over this vac leak crap!!

just my $.02!

no i didn't think it would be an electrical problem...but i swapped o2 sensors and now i am getting 100+ mv at idle in closed loop and a few cross counts pop up here and there while idling...blm is still STUCK at 150...maybe you are right? i will check the continuity of all the wires and such tomorrow...this car has had electrical problems before...

note i also sprayed carb cleaner in various areas with the car idling...i sprayed at the stripped bolt area...no change in idle...sprayed tons of vacuum connections...all around the plenum, vacuum block, fpr, you name it...no change in idle anywhere...i still need to get a gauge and get readings of vacuum...

 

[d0n_3d]

TTT

 

[JayLashua]

you might ocnsider switching your boost gauge for one that reads vacuum as well as boost?

 

[d0n_3d]

Originally posted by Eric Stage I
With no connection to the o2 sensor, you would see a constant voltage of about .400.

guys the problem is still going on...here's some more tests i have done

i unplugged the o2 sensor while the car was running...voltage was .396 steady

plugged the o2 back in...unplugged new ls1 maf sensor...no change in idle...i know my maf is good...it registers about 4-5 GPS at idle when warm and it goes up when i cruise accordingly...

i now get cross counts at idle with this new GNX o2 sensor...i never got cross counts before...idle mv is around 400-700 and then sometimes dips in the 100's

this is not o2 sensor related...i am working on getting a vacuum gauge to test my vacuum...where should i hook it up at? which lines? will they all read the same?

i am also getting a new ecm to see if my current one maybe bad...

i checked all ground and i don't have a problem with the grounds...i am still getting a code 44 at idle in traffic after car sits for 60 seconds...

blms are always around 150 and integrator always above 128...so if there was a vacuum leak it would have to be a MAJOR one because the car is adding fuel like a 502 big block! smells extremely rich...i don't get it...i am also going to spray more carb cleaner in areas to see what is going on....when i installed my powerplate it was installed with BOTH gaskets top and bottom...i get this code 44 with the pcv valve by itself...with the inline check valve and pcv, and just the inline check valve...so that is not the issue...

running out of hope here guys...i was also told that this is probably internally related like a bad cam lobe or lazy rocker arms or a bad valve...

 

[Iceman]

Did you have this problem before you put the Translator and LS1 MAF on your car?

 

[d0n_3d]

yes i have had it with the stock reman maf sensor...a new tomco unit...and now the ls1 maf sensor...does not matter which maf i use...

i just bought a vacuum gauge and i am getting 20-22 at idle, car warmed up, closed loop, this is plugged into the vacuum line going into the fuel pressure regulator...on the gauge it has a green shaded area that says normal and i am in the normal range...so what is up? no vacuum leaks?

 

[cjp69]

Did you ever get this figured out?

I just put switched from 36# injectors to 42#'s and all of a sudden I am having a similiar problem with BLM's reading at 150.

Thanks, Chris

 

[Roc87]

Ya, Did you ever figure it out!? I'm having the same problem with the Iroc, but I'm still thinking its a vacuum leak, I'm only getting around 8 inches of vacuum at idle, sounds like I have one heck of a cam! Have used two cans of carb spray looking for a vacuum leak and can't find anything. Turbo spools waaaayyy too slow for having a 3200 stall. If I pull off the hose going to my power brakes, my Autometer says I still have 8 inches of vacuum.

 

[Dan K]

While I'm not getting a code 44 anymore, blm at idle is pegged at 150 and int is moving back and forth around 128.
I still haven't figured out why my car is doing it either.
Funniest thing is I don't think my car smells rich at idle?

 

[d0n_3d]

my car still is pulling a code 44 at idle...but it only does it once and a while now...it doesn't do it ALL the time when i let the car idle...i don't know why...but it still does it alot...i hooked up a vacuum gauge to my fuel pressure regulator hose and i get 22 hg of vacuum so i have plenty of vacuum there...

i've done everything you can do basically to solve this problem except take off the intake manifold and replace the gasket...since i have had this problem for about 2 years now with all different kinds of combos i believe my problem is internally related somewhere...when i get a chance i am going to take it to a shop and get it vacuum tested...my car runs extremely rich at idle still and boy can you smell it...thank god i don't run a cat because that thing would be toast in a few days...

 

[SPOT MY 6]

d0n_3d,

How far are you from the south suburbs of Chicago? I live in Orland Park. I would be willing to help you with your problem. I will PM you now so check your PM's.

 

[Dan K]

I'm about an hour west of Orland Park, so if you're going to help Don out with his car I'd love to come hang out while you guys are screwing with it and help out however I can. Maybe I can learn something.

Edit: After being out in the garage for a little while, I found a crack on the driver side header between 3 and 5. Never noticed it before. Hopefully after I get this fixed the problem will be gone.
Sigh....at least I found a potential cause for these high blms.

BTW, will a cracked header cause blm's to be higher at all loads and rpm, or is it just an idle problem?

 

[mgmshar]

Here's a couple of ideas that I haven't seen anybody comment on yet...

Start the car, warm it up, and then rev the engine to about 2,000rpm for about 30 seconds. This will ensure that the O2 sensor is HOT. Better yet, go out and drive the car under a nice cruising condition (like 60mph on the highway). If your Turbolink starts showing more normal BLM's, O2 voltages, and cross-counts, then one of the following is happening:

1. Your O2 sensor is cooling off at idle, and it's not cross-counting like it should. Please note: Every un-heated O2 sensor will cool-off at idle and not respond nearly as quickly to changes in A/F ratio. In fact, I've noticed that on my GN, the O2 sensor would eventually cool-off to the point where it stopped switching entirely, if I allowed a really long idle (like 5 minutes). When that would happen, the O2 voltages would go down, and the BLM's would climb. This is why all modern cars use a heated O2 sensor. I used to test O2 sensors for Chrysler, so I'm pretty sure about this. Don't believe me? Install an unheated O2 sensor into a stock GN with a stock idle speed (700 rpm). Use DS or a multi-meter to watch O2 voltages while you are revving the engine, and then watch what happens when you let the car idle. A poisoned or "weak" O2 sensor will be even worse. Depending on how your chip is set-up, it may or may not handle this correctly.
2. You have a vacuum leak, as others have suggested. This is causing too much air at idle. Put a vacuum gauge on the car. You should be pulling about 15 to 17" of vacuum at idle in drive. If you're not, then you probably have a vacuum leak.

If, while you are revving the engine to 2,000rpm, you still don't seen normal O2 voltages and cross-counts, then I would check the following:

1. The O2 sensor is poisoned and not working.
2. The wiring to the O2 sensor is somehow messed-up.
3. The O2 sensor doesn't have a good ground path (not likely).

That's how I would tackle this, anyway...

 

[d0n_3d]

well i have tried various checks of the o2 sensor with steve wood and i never exactly came across a problem...he said it was wiring related somewhere but man i just cant find any wiring problem...

i have gone through 3 different o2 sensors INCLUDING a heated one...still got the same stuff...i am not running a brand new GNX sensor and still get the code...

i tested all the ecm wire pinouts and pretty much all of them checked out good and normal according to gnttype.org

i have checked for vacuum leaks...i pull 22 hg of vacuum at idle from the FUEL PRESSURE REGULATOR line...haven't tested any other lines yet...but according to steve wood that is well above normal and indicates a very healthy motor...my motor is bone factory stock to the valve springs btw at around 86k miles

several guys and steve wood also have suggested that i might have a leak in the intake manifold internally and i wouldn't be able to see it from the outside without taking off the manifold...i haven't exactly checked that since that would take a long time to do...but if i can't find the obvious culprit i will probably have to do that...what i need to do really is get my car vacuum tested somehow and check the ENTIRE system for a vacuum leak...i was told some shops do some kind of "smoke" test? can anyone help me as far as vacuum testing the car? i would be willing to drive out to illinois sometime if someone can help...thanks.

 

[Steve Wood]

Actually, I was never sure if it was wiring or not. To my knowledge you never got a digital meter so the quality of the grounds could be checked properly, etc.

The high vacuum bothered me a bit as not all vacuum leaks show up as a drop in the gauge vacuum and the high vacuum might be from your idle speed rather than a sign of no leaks.

It is certainly a confounding problem as nothing is obviously wrong, and yet, it is obvious that something is wrong.

 

[JDEstill]

I would give up on doing vacuum leak checks and do a pressure check instead, as described here (as well as in another thread or two somewhere around here):
http://www.turbobuick.com/forums/showthread.php?threadid=75615&referrerid=908

I found two leaks I never knew I had. One leak, around the throttle shaft, I would have *never* found doing a vacuum leak check because it only leaks there when the throttle is open! And I never would be working the throttle with the car idling while I'm trying to find a vacuum leak, ya know?

Anyway, I think it'll be easier to find leaks with a pressure test since the engine isn't running, so it's nice and quiet and you just find where the air is hissing out.

John