turnUP

Hello everyone I have a couple of problem, just put a 93 lt1 from a display corvette in to a 95 z28, changed everything i need to to get it right for the 95. I got everything put in and went to fire it up and boom backfire through intake... now I've crossed wires before so I like to triple check and still did it, Ill quad check next time.. anyway i knew that's what it was, switched them and tried again, fired right up rpms held steady at 900, did the "valve ring seat"<-if that's what its called, press the gas lightly let the rpms go up and down and not sit in one place. Problem 1...i let it idle for about 10 mins went to press the gas a little and noticed it seemed to want to cut off when i let off the gas fast, when i easy off its fine, I cut if off because I had only put in 3 gals of gas after emptying the old out, it was late so i went home.

Next day first thing i did was remove the air filter from the throttle body to check around for leaks..., none .... going to put it back on i heard a rattle, the boom blew off the honeycomb from the MAF. had an extra so i swapped them out. Fired right up,Didn't do the let of gas thing at all I figured it was the MAF. Problem 2...i was looking under the hood and noticed a bright white flash from driver side under manifold i couldn't see where and had no one to hit the throttle while i checked from the bottom so i cut if off to check wires and things. Wires looked good couldn't find where it was coming from.

Here is the title problem put everything back before I started it I hooked up my laptop with an aldl cable a free 94/95 software from here. connected and started the scan, went to start and only cranks, will start if i depress gas all the way, clear flood mode, sounds like only 4 cylinders and will only run as long as i give it any gas. Problem 3 i stopped the scan on the program unhooked battery only negative and checked the wires I messed with( #5, #7 plugs oil level, oil pressure and o2 sensors to see if they were the light flash) i get under the car and noticed the subframe is electrified, slight tingle nothing I couldn't touch without it hurting but I didn't understand why. I unplug the battery all the way and it was still there, I couldn't believe it
Then I remembered my laptop was connected to the car, only power connected to the car, I unplugged the cable and subframe is normal, I closed the software, just google chrome running and plugged the cable back to car and subframe back energized.

ok

Problem 1 wanted to die when let off gas fast-- MAF was blown up I'm thinking that was the problem because it didn't do it after I swapped it. but what do yall think causes that? is the honeycomb connect to the sensor or just a screen?

Problem 2 light flash under driver side exhaust manifold-- very bright i only saw it when i hit the gas but not everytime. i figured sparkplug wire but the look good no burns or cuts, but ill swap them, flash from anywhere else on that side

Problem 3 Laptop shocks me through aldl connector subframe, starter, tranny and cooler lines--very faint but i would think anything at all is not normal, and car was running without the laptop, not running with it, I couldnt try again without laptop plugged I was already running late.

Rechecked grounds, I cleaned the ones i needed to remove before I put them on the first time, never touched the ones i didn't need to remove the engine, came out the bottom.

Hopefully someone might know what i missed. Thanks for Reading.

turnUP

UPDATE I removed the plugs on the side with the flash and noticed a lot of spark plug grease in them (they came with some in the boot already) cleaned most out.

Fired her up without the laptop and it started and ran ok, went from 600 rpm to 1000 slowly and held there. Flash is gone.

I won't hook the laptop back up until I hear from someone.

it did cut off when i hit the pedal fast, not hard maybe 1/4, and it didnt do it when i eased on the pedal. I do realize that i need to readjust my valves i hear a lot of clicking, I did the spin and tighten until you feel friction method. I noticed maybe 2 valves on each side were up further then the rest. From what i could research the vales could cause this.

No check engine light, no flashes under hood and the laptop never went back on.

just want to know the most sure fire way to adjust valves. I took a video and will figure out how to upload it later.

edit. by the way no electricity shook from any part of the car without laptop plugged in.

GaryDoug

Do you have a car battery charger attached and plugged in? Is the laptop connected to an electrical outlet in any way (charger cable, etc..)?

Zee man

Running method, but it is also the messiest. Adjust one rocker at a time. loosen until you hear clacking, then retighten until noise stops add 1/4 turn.

turnUP

Yes GaryDoug it was plugged to the charger the whole time it was plugged to the car.

Thanks Zee Man Ill look around to see if I can find a picture of how they protected the rest of the engine but I would rather do it with the engine off.

GaryDoug

Some battery chargers are not particular on how they float the charging ground cable, and should never be used with a line-powered laptop at the same time. Many laptops have been fried catastrophically that way.

turnUP

Thanks GaryDoug, So should I try without the laptop plugged to the charger? When I did run the software the numbers that popped up were definitely wrong.. i.e. 7400 rpm, speed 68.... i can't remember the rest.

I have a scanner obd l&ll but when I connect the aldl cable to it it auto picks which l or ll and the car type by the cable Im using, Which told me the cable was handa, I don't know if that would cause troble for the software I don't think so because the software lets me pick car type and year.

GaryDoug

Yes, don't use more than one line-powered device attached to the car at the same time. However, that doesn't guarantee there won't be some voltage on the car ground from the remaining device. If I suspected something was floating the car's ground to an elevated voltage, I would use my multimeter to find the culprit (measure body ground to earth ground), and never use it again.

turnUP

Yes I haven't used the laptop since I realized it was the problem. Using the mutimeter showed nothing wrong. I used a scanner that I have, it can't read the codesnI just wanted to see if it would do the same as the laptop but it didn't. I would like to be ableto tune it sometime. At least be able to moniter it.

GaryDoug

What are you saying, you want to use the laptop? Can you not run it on battery alone without the power cord?

Injuneer

Somehow, he appears to have missed your earlier comment.........