mrmint69

I noticed that when the rpm's are going up there is an increase at every point on the datalog. When it goes over 4000 rpm's there are some that go down and then back up. Here are 10 straight readings so you can see whats happening. 4275, 4175, 4325, 4300, 4450, 4475, 4600, 4575, 4700 & 4675. I was guessing miss fire but how would you check this and what could be causing this? I noticed that when i go less than full throttle (50%-75%) my car feels strong and pulls great and the difference when i go WOT is not much better. My 0-60 times trying to go as fast as possible is only 1/4 of a second faster than than averaging 60% throttle all the way through. Fuel pressure looks good all the way through the rpm range.

MeanGreen97Z

Recheck your clamps for your hoses and see if either something is letting off pressure from the SC. What is your AFR?

mrmint69

I've had a boost gauge on it and it seems to be building pressure all the way to 5 when i finally let off at 65 or so. I am getting a wide band so i will be able to answer your question. Do i need a sensor for both sides? Any suggestions of brands and types?

elisowski

I am having the same problem, and I am not supercharged.

I noticed we have a lot of the same MSD equipment. I put new MSD 8.5 wires on with the rebuild this spring. I have since removed the stock opti and added the MSD pro billet opti, then I changed to a new MSD coil. I had a MSD 6-Al on the car and I switched to a MSD Digital 6.

I am thinking that it is the MSD 8.5 wires. I've heard bad things about them.

Are you logging at 10 records per second? I'd like to see you data logs if you can e-mail them to me. lisowskie@contech-cpi.com

Are your MAP readings doing the same thing? Mine are jumping up and down with the RPMs.

Go here and start reading with the third response:
https://www.camaroz28.com/forums/sho...d.php?t=551427

Are you down on power?

My RPM readings were doing this all summer as well as the MAP. I finally went to a dyno and made some runs. Read along and see if we have a common problem.

read here also:
https://www.camaroz28.com/forums/sho...d.php?t=557207

mrmint69

The map should never go above the bar. Mine was doing that and i replaced the connection, map and seal and it stopped doing it. My reading on the map go from idle up to the bar and do it steadily. I use Freescan so how exactly do i email them to you? Look at my mods and my track times. People laugh at me and tell me i should be closer to 12.92 than 13.92. I have done many small things since i ran last summer so i hope i have cut a lot of time off. My temp sensor in the water pump would read 70 degrees at start up and it was 25 degrees outside. I replaced it and now it runs a lot better while warming up. I had several exhaust leaks but hope i got them all. I did 75% of my mods all at the same time so its hard to figure if any screwed up my performance. Since i bought the car and ran mid 14's it has only gotten faster so it hard to know what normal is but it should be a lot faster than it is right now.

elisowski

For some reason, it seems like we both have the same problem. Your car is way down on power and so if mine.

I'm supposed to have 410+ RWHP and I only have 312. My car should run 11.50s and it running 12.20s. I should MPH around 118 and I'm getting 111.

There seems to be a mis-fire but the air fuel ratio is right where it needs to be. A mis-fire would show up as lean due to the un-burnt oxygen passing over the O2 sensor.

For some reason I think that we are not getting enough electrical power to the coil, or we are not getting the ignition advance that we are commanding.

I found another guy who was having the RPM problem. His rotor in his MSD billet opti was not loc-tited from the factory and had come loose. He took it off and replaced it and used loc-tite and his problem went away.

My car pulsed the RPMs with the stock opti on it.

Another problem I had was with the MSD 6-AL. When I would rev to 6000 RPM, the RPM would act like it hit the rev liiter, except that it was not a soft hit. Meaning it would violently jump form 6000, 4000,5200, 3000 like bam, bam, bam.

When I would dis-connect the MSD and run on the stock ignition I could rev smoothly to 7000 without an incident. But it was still low on power and slow at the track.

I swapped to the probillet and it would do the same thing but it raised to 6500 rpm. I swapped the 6-AL for a Digital six and that part went away.

Was your car down on power before you added all the mods? Was it comparable to other stock Z's?

Have you tried switching back to the old plug wires? If it's not the plug wires, I think it's something in our electrical harness.

As for Free Scan, if you save the files as a comma delineated file (It's on the lower left hand side of the main menu), they would probably be saved as a text file that could be opened in notepad and then imported into Excel.

mrmint69

There is a fuel pump booster that is plug and play for $79 on Summit. It raises the voltage by 2 after 70% throttle. It would also help with other electrical issues dropping while going wot. My voltage on the datalog is as high as 12.7 while driving and goes to 11.7-11.9 while doing a 0-60 run. I think a stock 94z runs in the high 13's low 14's stock and i was closer to 15 than 14 so it was down on power. I added the mods and got about the right amount of hp gains but since it was bad before it still shows just as low of a percent as before.

elisowski

I ripped out my TC today to send it back to TCI.

I am going to replace the plug wires with some stock ones while it is up on jack stands.

I had a problem with the MSD wires earlier this summer. I had them in heat shield tubes due to burning some wires on the old engine, and I was not going to go through that again. Since I had the engine out I was going to insulate the wires and put the boot protectors on also.

When I had the hood open at night, the #5 and #7 wires were all glowing blue on the outside of the silver heat tubes. Looked like one of those static electricity ***** at a science fair.

You can read about it here.

http://www.z28.com/forum/showthread.php?t=106630

I still have the boot protectors on, but they are coming off when I put the new wires on.

I'm not trusting those MSD 8.5 mm Superconductor wires.