playa7970

ok here we go... heres my log file before my story http://www.yourfilehost.com/media.ph...845camaro7.csv

Heres the problem im experiencing......
-cam which i cant reveal ....23x 23x 10X LSA and i only get the backfire out of the intake from 1000rpm to 2000rpm example... ill be driving no matter half throttle or WOT itll seem like not enough air is comming in (but i dont know) then itll pop out of the intake or backfire whatever you wanna call it but only between that rpm range,if im above 2000rpm im alright, but the car is running extremly rich because i believe of the HIGH MAP causing the pcm to dump more fuel....

Here is what my Z runs.....
1. My exhaust is somewhat loud (only running a muffler)
2. I always run premium 93 octane
3. 12.1 compression
4. Mail order tune
5. every sensor/component is new exept the FPR
6. MSD Digital 6
7. Taylor 8.5 Wires
8. New OEM Opti Conversion

Here is what i checked.....
1. Valve Adjustment with 1/16 preload
2. I pulled a spark plug and the color is whitish/brownish no oil on them
3. I replaced the MAF
4. Spark plug wires are not crossed
5. I checked for vacuum leaks by spraying intake cleaner all around

Old threads--
http://web.camaross.com/forums/showthread.php?t=461543
http://web.camaross.com/forums/showthread.php?t=459873

Injuneer

I fixed your "link" to the old thread so it would work.

You might also want to reference the thread where I spent a bit of time looking at your data (and noted that the data logs were incomplete).

http://web.camaross.com/forums/showthread.php?t=459873

playa7970

thanks again fred sorry for being such a pain in the a** i just hope this turns out to be something small and not big

Injuneer

Have you looked into anything I mentioned, like the erratic MAP readings? .....possible MAF miscalibration? What did the cam supplier say about your MAP at idle?

playa7970

well heres the message i got from the cam supplier "No clue what the kPa should be for the cam....It should have 10-11 " of vacuum at idle. 82kPa sounds like to have a leak to me, that seams WAY high on the charts." as for the erratic map reading could that mean a bad map sensor even though the previous one i had did the same and as far as the maf how do you calibrate one, i bought a vacuum gauge at discount yesturday so im going to try that in the next 15min, then what ill do is disconnect all the lines and plug them to make sure is nothing external leaking i got that idea from 95ta

Injuneer

Vacuum = Barometric pressure - MAP

From your records at 100kPa barometric pressure, you are running ~82kPa MAP. The difference is a vacuum of 18kPa, which converts to about 5-6"Hg vacuum. To get the 10-11"Hg vacuum that the cam supplier quoted, you would want to see MAP readings around 65-68kPa.

You should have a code for "high MAP".

Check the MAP sensor harness connector. Jiggle it and see if the MAP reading on the scanner jumps around. Look for signs of damage.... the MAP connectors dry out and start to crumble, making poor contact.

Is your MAF stock? Has is be "ported" or molested in any way (even screen removed)? Did your tuner ask you what MAF sensor you were using?

playa7970

the code that im receiving is 33 high map and the MAF is about 1 week old and it still has the screen in it and its a regular gm MAF ill go outside with my laptop and take another reading while jiggling the harness maybe the connector isnt making good contact its worth a shot brb

playa7970

ok i hooked up a vacuum gauge and you guys were right im getting about 7hg of vacuum i only got to disconnect the brake booster and plug it before it started to rain but ill try again later today

Sweetred95ta

Man, you have these threads all over the place. I think I've answered in two of them and this will be my third. You keep jumping around from thread to thread and it's hard to follow. The 383 is cool and everything, but pictures aren't going to help solve your problem. I would think that if the vacuum could be fixed with more timing, then the car would build more vacuum when you bring the rpms up. Fred and I have noted about the same things wrong with your log, but in different posts. Have you checked the vacuum with everything else unhooked yet? I guess this is the right thread to post in.

playa7970

yea i could be called the camaroz28 ***** when it comes to thread posts lol but the only thing i disconnected and plugged so far was the brake booster then it started to rain but as soon as it clears up i still have to cap everything else and keep you guys updated sorry about the thread jumping

playa7970

hmm so i ran the vacuum test and still only made about 8hg of vacuum at idle with everything plugged, question does the tubes below the throttle body need to be plugged as well or is that just coolant passages i cant recall but its by the iac sensor

Sweetred95ta

No, you don't have to plug those. As long as you took care of the PCV (driver's side on the intake), you should be fine. I'm at a loss to why you have such little vacuum. Didn't you say that the car runs fine other than the knock? I bet the knock is directly related to the vacuum though. I'm out of ideas. Maybe someone else can offer up something.

playa7970

trust me brother so am i i called ion from mad z28 and he told me it was because of me having a 383 and such a big cam and lobe separation but you have a bigger cam then me and your fine, when i hooked up the gauge i had a steady reading as i revved the car, and the car drives fine above 2000 rpm but if i drop below that... is when i dont get enough vacuum to compensate i guess??so what is my solution vacuum pump?

playa7970

*update* hey can my vacuum problem be from eliminating the baffle from underneath the passenger side valve covers??? the mechanic that did my motor swap removed it and put a breather in its place, was this a mistake? if so how can i fix it

slopokrodrigez

I have a few issues with the things you're doing or NOT doing.

First off you said in the first post "but the car is running extremly rich because i believe of the HIGH MAP causing the pcm to dump more fuel"
HOWEVER you say in the same post:
"2. I pulled a spark plug and the color is whitish/brownish no oil on them"
Which for a layperson, does NOT indicate the cylinder running rich.

In post #8 you said "the code that im receiving is 33 high map and the MAF is about 1 week old and it still has the screen in it and its a regular gm MAF ill go outside with my laptop and take another reading while jiggling the harness maybe the connector isnt making good contact its worth a shot brb"

Never heard another word about the DTC33. ????????? Do you still have a MAF failure or not? MAF's are easy to check with a multimeter for proper operation. Don't have a lot of choices here, MAF, wiring or PCM. Eliminate 2 of the 3 and that leaves the last one.

You mention the vacuum at idle but what about above the point of the problem like 2500 rpm's?

You mention baffles inside the valve covers and a breather on the outside which is two different animals. Do you have a PCV system hooked up? Perhaps you aught to look at what your crankcase vacuum level is after you get some other problems sorted out.

Never EVER break in a new engine with loud exhaust. You want to be able to hear anything going wrong with the engine right away.

Don't really care that you post too often but I see no need to post pictures of the engine or the car sitting outside. However, since you bothered to take up space with the pictures, I'm going to comment. WHICH brings me to the next point.

I find it hard to believe there are deciduous trees and that it can get icy like that in Naples Florida. The pictures that use up bandwidth need to be pertinent to the problem/story at hand.