Hello everybody. New to the forums here and z28 world put of New Jersey.I'm a 20 year old college student so money is tight. I've built 4 cylinder dsms from the ground up but never touched a v8 Chevy so be patient with me.

Yesterday I picked up a 94 z28 With an edlebrock intake manifold bbk throttle body edlebrock headers and STP exhaust and an msd ignition. with most of the interior and body panals in pieces. Today I got everything together and was not able to get the engine to crank. (The guy I bought it believed it was the VATS going haywire). Well finding that one wire was messed up going to the power for the starter, I just replaced it. I know it isn't the vats be a use I'm getting fuel windows work and the engine cranks.

Now when I crank it the motor turns very slow. Well slower than I think it should at least. The battery was just bought today. The spark that i was getting was orange and not very strong looking or sounding. So I unhooked the msd ignition and it made no difference. I went today and bought a new ignition coil with no luck. It will very rarely pop out the exhaust and cause a fire because of the fuel dumped into it. (Open headers). I don't want to dump a lot of money into this so I want to be certain with what is wrong with it. I hope this was enough info and I hope that I gave enough information

Wires and plugs are near new.

 

Youre going to need an optispark distributor, i justbwent thru the same problem with my z28. Would crank all day long and maybe hit once in awhile..

But before you dive into that rent a fuel pressure gauge for a chevy. Oreillys carrys them. And hook it to the valve at the back of the intake. It looks like a valve stem but alittle bigger. And see if you have 44psi with the KEY ON ENGINE OFF! And make sure it hold psi. It shouldnt drop more then a few psi every ten minutes if it does at all.

If it drops rapidly you need fuel pump or the diaphram on the fuel pressure regulator is bad. If you think its the FPR pull the vac line off it and see if it has gas in it or take the end that connects to the intake side and blow gently into it if you can blow air into it it needs replaced.

Also be sure to check ALL grounds. If youre not sure where they all are take a set of jumper cables and place one side onto the neg side of the battery and the other onto a good solid part of the engine like the alt bracket and try and start it if it starts you have a bad engine block ground. Replace it.

Also a compression check wouldnt hurt. If im thinking right they should be at 125# give or take 5 or so you will be ok.

Also take the icm into an autoparts store and have it tested about 10 times to make sure it never comes up bad. If it does 1 time out of the 10 id replace it.

And if all of those things check out to be good as a last resort you can measure the ohms in the chip olfor the ign key and duplicate the EXACT amount shown on the digital screen and bypass the vats system to make sure thats not the problem. If its not then find yourself a cheap used or junk yard opti and use my "how to test your opti without it being on the car" write up to make sure it has good spark before you install it. And replace that.

BE SURE YOU BUY A SPLINE DRIVEN 1992-1994 STYLE OPTI THE 1995-1997 WILL NOT WORK WITHOUT CHANGING THE TIMING COVER AND CAM GEAR!

If you need any other help feel free to pm me, fred (injuneer) or rob (shbox) and we will help you all we can. If you want to pm me ill give you my cell number and you can message me anytime with questions or concerns.

 

Thank you very much for the reply. I'm going to try and get all of that done this weekend. Hopefully it is not the optispark I hear they're a pain in the butt to chang. Any other suggestions please feel free to lay them on me.

 

Scan it for codes. Problems with the optical cam position sensor inthe Opti will set codes. Problems with the high voltage section (cap/rotor) will not.

 

Injuneer I see that you're in NJ. What part? I'm in Mount Holly and I'm willing to pay anybody that comes out and can give the right answer

 

I was going to say scan it for codes aswell but for some reason its extreamly hard to find an autoparts store with an obd1 scanner anymore plus he cant get the car there to have it scanned unless he trailors it.

But the opti isnt too bad to change. I just replaced mine in 30 min a few days ago. But ive done it a million times lol just remove all of the hoses connecting to the water pump. Take a 14mm deep and shallow well socket and take alll of the (6) bolts out of the water pump remove that but be sure to remove the electric fans too. You can also remove the radiator if you need more room. But the fans will only come out the bottom most of the time. So the cat will have to be on stands. Then take a 5/8s socket and remove the crank balancer bolts (3) and take a big pry bar or crow bar and see if it will pry off. If not take a propane torch to the area surounding the hub then pry it off but be careful of the hub it will be hot as hell. Then spin the crank hub with the same 5/8s socket untill two of the fingers are up and it looks like a y and take a 3/8s socket and remove the 3 bolts and pop the opti off. It only goes in there one way when you re install the new one. It will have a bunch of splines and a solid looking flat spline you have to have those two lined up with the opti and the cam gear l. The opti should go on easy with very very little ti no force and sit flush against the timing cover you shouldnt have to work the opti flush with the bolts. After youre dont installing the opti try and start the car with everything still apart. It wont hurt anything if you only run it a few mintues. But when you do start it make sure it revs freely isnt missing and you should be good. Its also a good time to replace the plug wires too.

 

Software scanner..... you can make the cable for $20. Don't have to drive the car anywhere.

Find a friend that has an OBD-1 scanner.

Or.... actually buy a scanner. I learned more about how these engines worked from watching my Scanmaster than I did out of looking at any book. Cost a few bucks, but saved me a lot more in the long run.

 

How can you make one for 20$? Pm me that info id love to make one for my z28 cause im planning on doing a 1994 plus conversion and adding a maf. So it makes my tuning alot easier

 

See post #13 in the thread "stickied" on the "Computer Diagnostics......" forum:

https://www.camaroz28.com/forums/com...6/#post6944456

 

Thank you everybody especially supersport. I will definitely try and get the opti replaced on Saturday. Luckily my radiator is already removed so I will have no problem getting into there. If it doesn't work I can always just return the optispark. My place around me let's me do those kinds of things because of a corporate account I could use. I hope it works out and I cannot wait to get this thing moving!!

 

What brand Opti will you be buying? If it isn't a GM unit (AC Delco or Delphi) there's a good chance it won't last very long. No matter what you buy, you have to open it up and loc-tite the rotor screws, or the rotor could fall off.

Reading the codes could save you some money and time.

 

Fred is right. Make sure you loctite those screws. I cant tell you how many times ive seen a rotor screw fall out and then snap the other side off. Also put it back together with some high temp silicone to make sure no water gets into it. But before doing any of that if you plan on taking it back if it doesnt work just quickly put it on there and snug the bolts down and make all of the connections and try and start it. If it fires up just pull it back off and loctite and seal everything up.

Be sure to post pictures along the way we love to see progress. And i for one have gotten some awsome deals on fbodys but youve gotten a great deal on this one. I bought a 94 z28 ex police car for 100$ after finding out it needed headgaskets and a trans i pulled the t top headliner out of it and the radio then sold the car for 1000$

 

That's my plan I picked up a delphi and it will be there Friday at the store hopefully. My plan will be exactly what you said for the installation supersport. If I need to I will throw some paint on the car and sell it in the end. Say it did run with those mods and it does have a rebuilt trans with paperwork and fresh paint what would a car like this bring in?

 

I'll let you guys know tomorrow if this beast lives. If it doesn't it's for sale

 

Well it didn't work. Damn.. same issue.