96,z28,5.7L,6-speed manual
ran but not 100%, replaced MAF sensor (was absolutely sure this was an issue) now it runs ****tier than it did???!!!
anyone have a similar issue?

 

What diagnostics led you to replace the MAF sensor? Codes? Running rich? Running lean?

Did you try cleaning it?

 

Codes on 2 separate ODB readers. Both threw P0101 every time.
plus a gas smell, choppy accel, a miss, mpg was realistically 7-8 mpg. (20$ every time I drove it.)
replaced relays as well. MAF sensor was only 24$ on amazon.
also, wet tailpipe??

 

P0101 sets when the mass air flow reading from the MAF sensor differs significantly from the mass air flow calculated using the speed-density method. The error could be due to the MAF sensor, or due to things like a vacuum leak. Could also be due to faulty wiring, and the 96 is known for a problem with complete failure of the power supply to the MAF sensor due to a broken wire internal to the harness. It wouldn't be a totally broken wire, because that would set P0100. And, the speed-density calculation depends on the MAP, IAT and RPM readings.... so a faulty MAP sensor or IAT could be the issue.

If the engine was running rich for a period of time, the plugs probably fouled and need to be replaced.

What "relays" did you replace? Why?

I would also be suspicious of a $24 MAF sensor from Amazon. Most likely cheap Chinese crap. There's a reason a genuine AC Delco MAF sensor costs $100 or more.

You need to determine if the problem is the sensor or something else. There's a diagnostic logic chart in the 1996 factory service manual (free download available), but its fairly complicated and requires measurements with something like a Tech-2. If you have a multimeter with a "frequency" scale, check the frequency (Hz) on the yellow wire from the MAF sensor. At warmed up idle, you should see something in the range of 2,000-2,500 Hz. Anything from 6-10 gr/second on a PCM scanner.

 

Holy ****, thats the most information anyone has given me...so many people think they know but that engine ends up stumping the best of 'em. One of the reasons i love it so much. Well, so i plugged OBD back in and this time instead of 6 assorted codes (including but not limited to p0101) only 1 code threw. "manufacturer's code 1657"? So then i'm test driving and it really ran rough...shaky and **** until I got up into 3 -4k rpm range then sort of smoothed out. Almost like she hates going slow. Relays : cooling fans. Heated up pretty quickly in the beginning and she's got a brand new double radiatior. Fans weren't kicking on, so... You said it with the electrics. What a mess. I see the light at the end of the tunnel though, as I've rewired or replaced about half. Still a lot to go. Ever present is the gas smell, more now than before. Wet inner tail pipe. I didn't think to check the plugs though, You're absolutely right on that one. They are most likely fouled and have been for a little while. There are indeed many vac leaks. Been struggling to plug them and route them and what not for a few days now. The MAP sensor was my next target and maybe the FPR but that bitch is on the back side of the block against the fuel rail. As far as chinese crap probably. I intend to return balance to the universe and put good into her but I gotta figure out what is making her sick. This car is sentimental and I'm NEVER selling it. I will do anything to get her glory back. Thank you for the multimeter suggestion, I am going to try that right effing now actually. Also, any suggestions for the vac leaks? Smoke, or carb cleaner? Sus out all the spots? Do some of them simply need to be plugged or is there a line for every hole? Last question: on the air intake before the manifold, just after the MAF, there is a "T" in the intake right before it curves back towards the block, it shoots straight down and is plugged with a tennis ball....???? Any thoughts??
Again, much respect to you and I am grateful for your wisdom. We will be talking more, hopefully.

 

P1657 = skip shift circuit. Somebody probably unplugged the Skip Shift solenoid on side of transmission. As I recall….. plug a 2,000 ohm resistor into the 2-pin harness connector, tape it up. No more annoying Skip Shift (prevents shifting from 1st to 2nd at low RPM/part throttle - forces shifter into 4th).

https://www.camaroz28.com/g/picture/8154289

Have you checked the fuel pressure? Have you pulled the vacuum compensation line off the FPR, checking for wet fuel or strong fuel smell = ruptured diaphragm in the FPR. I accessed, replaced FPR many times without pulling the rails. As I recall, it's held on by a Torx-27 screw. Working blind with a Torx socket on a ratchet. Dropped the screw a few times.

http://shbox.com/1/fp_reg.jpg

You can spray brake cleaner or throttle body cleaner on hoses and gaskets. If the engine smooths out and RPM increases you've found the leak. Others use propane from an unlit torch, but that's a bit of a fire risk. Or WD40… but who wants to make a mess.

Ahhhh, the “donkey dong” on the 90° rubber intake elbow. From the factory there was an oval plastic pipe, maybe 15” long, closed at the end. Intended as a resonator tube or silencer for intake noise. People removed the tube to make it easier to pull, and install the elbow, or maybe thinking there would be some sort of performance gain (no). It was easy to plug with a cap from a particular Pert Shampoo bottle. Or you could buy a factory replacement elbow from a car with the 1LE performance (mostly handling) package. It didn’t have the opening cut out inside, so the air flow was a bit smoother.

Maybe air leaking past the tennis ball = air not measured by MAF.

http://shbox.com/1/elbow_bottom.jpg

Is this a car you purchased recently? If so, did it sit unused for an appreciable length of time? If so the fuel system could be messed up, including plugged injectors. Sitting unused for a couple years with a tank of 10% methanol gasoline leads to major corrosion and sludge.

 

FPR - I was going to just replace it because I noticed a tiny drip drip from the gas line connection, as well as a wet, and actually dripping vac line. So I bought a new one (chinese junk but real pretty, bright red, came with all the bells and hoses) and I couldn't for the life of me figure out how to bolt it up to the rails...just wouldn't go on solid. So...I ended up cleaning the old one real good, attending to that fuel line connection and putting it back on. Problem went away for a while but now has returned. I just gotta replace it for real this time.

Many, Many Errant Vaccum Lines...so many small to medium hoses or lines just dangling as well as empty spots where a vac line surely goes. Timely process but I know it needs done.

When i first got it home, the OBDII threw 9 codes at me. Now, only 3...
P1657 - internet said : Skip-shift/1 to 4 upshift system control circuit
P0441 - internet said : Evap Emissions - System "no flow" during purge
P0100- (initially threw p0101 so I replaced the MAF) but now it throws P0100 or Insufficient Signal (MAF)circuitP1657 Skip shift/One to four upshift system control circui P16m control circuit
Yes, yes it did sit in the back yard for about 3 years...so, here's the short version : My brother and I joined the military (me the Navy, him Marine corps) and I did my 5 and got out, he did about 8 and got shot up in the desert. They sent him home with the promise of excellent and unending medical care but after about 5 years of appointments and surgeries and headaches passed a freak blood clot while he slept and died in the night. This Camaro was his baby. He added a few aftermarkets to it, tuned it real nice and knew how much I liked it...then he died and left me the car. I have to get it back to its glory. The 'Maro has sentimental value, along with the fact that its my only form of transportation to and from work. When he died I went to his place and loaded it up onto a trailer and took it home with me. All tires were flat and mismatched, brand new radiator in the back seat, no battery, engine and its bay were taken over by squirrels and other varmits (chewed injector wires, chewed plug wires, blocked air intake (walnuts stashed everywhere except where there is a tennis ball). I've forsaken many other things to be able to sink $$ into her and she's come along way. I imagine there is a significant chunk still to go before she's 100%. Thats where I'm at currently. She runs like a friggin gizelle on crack though!!! Faster and meaner than anything else in my town, and this is Iowa! Everyone has a hot rod of some form in this state.

Once again, you are my savior. I will be tackling this today with all the ammo you've given me as well as replacing the MAP sensor that I had imported from china...it arrived yesterday. I'll let you know how it went. Thank you. Talk soon.
JB.

 

Sorry to hear about the passing of your brother.
Are the engine internals all stock? Any kind of performance mods to it(cold air intake, exhaust,etc)?