magic stick stage 3, dual springs, ls7 lifters, etc. supporting mods needed for cam upgrade.

tunes has been gone through thoroughly by multiple people. Don’t think it’s the tune
Got the wiring harness and about to try it out to see if that works.

 

If it’s wiring causing a misfire, it will throw a misfire code.

 

These are the worst things I found when removing the loom and tape. They don’t seem like problems that would cause anything to me?
Also the wiring harness I picked up was the wrong one.

I didn’t mention this earlier because I thought it had to do with me removing the negative side of the battery and not driving very long after doing it. But my trip odometer would reset to 0 everytime I start the car. The only time it didn’t was when I took it out for a drive on Friday night for about 25 miles. Everytime I started it that night the odometer would hold the mileage. I got home today and went to start the car and it reset. It reset the trip odometer as soon as I started the car. It read 25.6 miles when I turned the key to the on position, then when I started the car it went back to 0
This is why a mechanic said it could be the BCM?

 

Even though it might not seem that something will hurt a wire maybe it can. I worked on plenty of generators in my life time that cables/wires seemed good to go and there was damage. Like I first stated a bad short will affect parts of your computer because it's trying to compensate. You're trip.odometer reseting every time you turn your car on tells me there's something else going on. Like stated a few times already you're going to have to put in work. That car sat for a long time and had some issues. It's not going to be an easy quick fix. Your going to have to make choices as to see if you're willing to put time money and effort into getting this thing running right again. I would see if you can find a good bcm and try swapping it out.

 

Jace,

99 T/A's had a gauge cluster recall/TSB back in ~2001 or 2002. Probably around the time your car went into storage. Might be worth checking to see if that applied to your VIN.

My 99 T/A was affected by it and dealer covered replacement. The gauge cluster did some strange things like gauge sweep on start up when it started to malfunction. No idea how the malfunctions progressed beyond that. The cluster was OK until it wasn't. I don't think GM would have replaced mine if a random sweep on start up was the only issue.

I don't recall if Camaro’s were also affected.

 

I order all new connectors and I’m going to make my own harness. I also looked online and may just order a BCM and swap it out and see if that fixes it. I’m going to get this damn thing running good. Thanks for the heads up on the Bcm.

 

hey thanks so much, I really appreciate that heads up. I’m gonna look into it. Thanks again

 

Ok another quick question. I was looking up BCM’s and found some that were double the price of the others, but they say they work with all 15 keys (I think T/A only had 14) and has a 6 week return policy. These have been rebuilt. The other ones don’t say they work with all the keys. So I would need to know what number my key was, find a Bcm with that corresponding number, and then it should work?
So probably just lay the extra and get the rebuilt one. I’d it doesn’t work, I can return.

 

anything with a warranty and a good return policy is worth the money especially when it comes to electronics. 👍🏽

 

Just thought of this…
When I switch out the BCM on the trans am, won’t that reset my mileage, etc.?

 

Swapping BCM will not affect your mileage. Only cluster will.
That said I don’t see how BCM can affect engine driveability. Changing it is probably a waist of money and time.

1. Bad MAF (rare) or MAF wiring can cause issues you have. If your volumetric efficiency table is tuned properly, disconnect MAF and find out if problem is still present in speed density mode.

2. Once your HP Tuners comes in, set your tune in open loop at all times to find out if problem is still present, this will isolate any bad O2 sensors. Or simply disconnect O2 sensors and drive the car to see if the problem went away.

3. With HPTuners or good scanner, datalog/monitor engine misfire when problem is present to isolate any potential cylinder misfire. If misfire is detected, swap ignition coils with good cylinder and see if misfire followed coil. Do the same with spark plug and ignition wire one at a time.

4. MS3 is not small cam. Tune might still be your issue. As a side note, cam of this size may have some low rpm, light load surge.

 

I'd check all power and gnds. Reset when starter engaged will generate high current and voltage drop below acceptable limit.

 

Ok, I rewired everything with new wires and brand new connectors. Still cutting out. Changed BCM and it didn’t work either. I put the original BCM back in. I finally got hptuners. Ran a scan and this what I found. First picture is when it’s running fine. Second picture is when it cut out on me for a half second. Third is when it’s right back to normal. All within 1 second. it’s like my throttle response just leaves for a second. I noticed my O2 voltage drops and then comes back. What could cause that? Is that the problem?

Driving normal

I feel the car cut out, throttle response seems to leave, and then everything is fine again.


and back to normal

 

Looks like lean tip-in
My post #31.
Read and apply first 3 points. It should help you isolate the problem.

 

first, thanks for replying to the post.
secondly I just got the hp tuners 5 days ago and I have no idea what I’m doing. Annnnd I don’t fully understand what you’re saying. Lol. I’m trying to read up as much as possible on the hptuners and learn.

 

I think You got a big ole cam in there and not a lot of compression buddy, find us the cam card?

 

The Tuning School courses are a great way to get started.

 

If you've changed harnesses BCM and the issue is still.persisting its definitely mechanical. Are you sure that the cam you have is working well with supporting mods?.This question has to do with more then just a tune. Good compression, good air flow velocity, throttle response, intake manifold. Was the cam done by you or did you aquire the car with the cam already done.

 

Yes it’s a big cam for stock motor
Texas Speed Magic Stick stage 3
Dration .50 238/242
lobe lift .353/.353
valve lift @1.7 .600/.600
lsa 113

Ive owned the car for 20 years, had the motor rebuilt last November by a shop, they did everything on the motor. Drove it roughly 1000-1200 miles and didn’t have this problem. In June it started to not run good. Took it to a different shop and found melted wires and they fixed them. Owner did some adjusting to the tune and it’s been cutting out ever since.
I bought this car in 2002 with 42,xxx, drove it for 3 months and the motor went out on me. Didn’t have the funds to fix it so I put it under a car cover in my garage. Last September I took the car out of the garage and got the motor rebuilt and had them make sure everything was good to go.

Best way to explain what I feel
when I’m down shifting, and I try to rev match, when I push the clutch in and hit the gas it’s like there’s no response, I hit the gas pedal again and it’s back and everything is good.

I found the tuning school the other day. I will check it out. Thanks

 

I had a similar cam in my C5 5.7 with no issues. I think that messing with the tune after the wires where fixed maybe has something to do with this issue. After replacement of the wires the car needed to be run with you in it to make sure that there wasn't any more persistent issues steming from the short.

After that then the tune should have been left alone if you had non issies before. I don't know about turning I'm not a tuner am a wrench turner and a schematic guy. Maybe you should get an independent tuner with a good track record in your own area to take a look at the tune. If you have the same guy whonwrote your tune taking a look at the tune you have he will say everything is perfect.