getZ

I'm running much less of cam, 230@.05 and 480 lift, with 3.9 gears, 26 inch tire, 200r4, but am very happy with a 2400 stall. I figure as light as the z car is I could step down stall speed to 2000 and still be happy. My guess is a 3000 stall would work for you.

First you cannot see the pulsing with a meter. The only thing you can see off the y/w wire a meter is possibly a small voltage during cranking depending on how quick the meter and display can respond. Assuming you are getting an output from the ecu via the y/w wire. Did you verify the ignitor works with the test I suggested with the 9v battery? That should work. I have no idea what pin 5 is. Make sure when the ignitor is mounted in the car the body of the ignitor is bolted down to chassis. This is a must because it grounds though the ignitor housing. I even went so far as to attach all the body grounds together. Next, how are you testing for spark? If you are like most people they use a spark plug. This works but can be difficult to see. Did you put the plug at the input to the distributor? Don't forget the plug threads have to be grounded as well when testing. Take it one step at a time and work your way from the ignitor to the engine.

As far as getting rid of the transistor, the answer is no. At least not with the stock ecu unless you want to a few more modifications. I was unable to find a replacement transistor that worked right. Not to say it can be done, but the original transistor had part no to reference. I had a factory manual but I gave it away when I sold my turbo motor. I can't remember if it was a PNP or NPN transistor. Yes, there are different types and the wrong one won't work. A while back I wrote up quite a bit on "ignitor," if you do a search. Do not hook that coil up to a constant 12 volts, it will overheat!

yes, you should see pressure on the rail after the ecu thinks the engine is running and your fuel system is working properly.

Your engine shouldn't have any problems so long as you have at least 3 or 4 feet of pipe to keep cool air from back flowing into the head, but the local police my have a problem with it.

There is an easy way to test both style CAS for z car turbo engines (81-83), but both depend on the fuel circuit working because that is the indicator that the ecu is sensing. The 81 is mounted near the bottom pulley. I removed the sensor from the mount and ran a small screwdriver across each little pickup (I think there were 3). Each time the pickup was sensed by the ecu the fuel pump would turn on for about 5 seconds. You are basicly fooling the ecu into thinking the engine is running. On the later style dizzys, remove the dizzy from the engine and hookup the wiring. Then spin the dizzy by hand. The ecu thinks the engine is running and turns the fuel pump on. Both are fairly simple to do unless you can't hear the pump running.

I agree about a bad ecu, but before you give up on it, I would double check your input voltage and ground. It's very odd for a system to fail with a voltage. Usually they go dead. I scored an ecu for 20 bucks on ebay, but that may have been lucky.

I have never bracket raced, but I always thought you wanted to run as big a radiator as you could fit to give you more capacity to absorb heat and give you better consistency. I run an arizona z car radiator on a small block chevy and it fills up the whole front. So far the car runs at 180 to 190 degrees. I think the only way you could fit a larger radiator is to cut the frame rails.

By the way, the lowest point on my car is the oil pan and the transmission pan. This is a stock 350 oil pan and a 2004r tranny. If your car is lowered with a bigger pan it will get that much closer to the ground. I've seen some other posts with people complaining about full length headers having fitting problems with oil pan kick outs.

I can remove my oil pan wihthout pulling the engine. I changed timing cover up front and landed up using a one piece gasket on the bottom. It takes a little manuevering, but it can be done. I have my engine set forward as far as it can go with a JTR kit so the crossmember sits further underneath the engine than some others.

The yellow white wire is the computer output to the ignitor. It should be a series of pulses, but you cannot see this with a multimeter. I had to use a digital storage o-scope to capture the signal. The signal should only be pulsing when the engine is either running or cranking. For the computer to send an output it must see the engine turning which it sees from either the distributor or crank sensor depending on the year engine you have. You mentioned two yellow/white wires? There should only be one coming from the computer. There is a yellow and a yellow with a white stripe.

When do you get a voltage? Is it when you are cranking? How big is the voltage?

You have it backwards. The black white goes to switched 12 v. The terminal on the ignitor is direct short to the switched 12v. The blue is the grounding connection to the negative end of the coil. As far as the yellow/white wire check the "you damn fool" write up. That part is easy to follow. Just make sure you have the right end of the connector hooked up. It goes from the computer to the ignitor.

My dart heads rest the plug boots right on the patriot shorty header but it's nothing that couldn't be fixed. Shorty headers are kind of a pain to dimple. I had to get kind of creative with a press and a section of pipe used like a lever to be able to reach inside the area that needed to be dinged. You can use a ball been hammer but it makes it ugly.

Coils are pretty tough in general, but I don't know about ignitors. I do know ignitors going bad seem to be pretty common.

How the coil works is it always has 12 volts hooked up to the positive side when the car ignition is in the on position, but the coil negative end is not connected until the computer sends a signal to the ignitor. The ignitor recieves the signal from the computer and grounds the negative end of the coil. By the way, the ignitor body is the ground connection so it has to be bolted down. Absolutely do not wire the coil directly across the battery for an extended period of time, they blow up. I know this for a fact.

Too bad I didn't see this post 8 years ago when I built my first stroker. I put small hole in the oil pan rail getting a little happy with the grinder. Since then I welded it up and regrinded it. It seems to have held up fine, but the engine has never really seen any road time. It's in a 73 camaro that just sits in the garage waiting to be finished. What do you think about hard blocking the bottom inch of the block?

The same happened to me on the initial motor break in. I had about an eighth clearance between the boot and the header. After replacing the bad wires I wrapped the boot end with heat reflective tape and that fixed the problem. Now that the engine is more or less broken and the timing is set, the headers don't get that hot. They were glowing bright red during break in. My shorty headers were kind of a pain to dimple. It's hard to get a nice angle on the area that needs to be clearanced.

If drag racing is your primary concern you can do a lot with suspension tuning. I'm always amazed when I read the corvette forum and see some of the 60ft times guys are cutting with a bone stock engine. My suggestion would be to get a g-tech or similar meter and kind of do a trial and error with clutch release. Some times the car may be bogging, but the alternative may be excessive tire spin. Keep an eye on your 60 ft times as they are key to tuning your launches. Of course a drag race suspension can be a compromise over a road handling suspension so finding a balance is what you may need to do.

Sorry man, I've got to go read some of the schematic stuff before I can answer intelligently. I don't remember what all the pins were.

The most difficult part about modifying a tank to me is sumping it. That was the most time consuming part. My tank is an old 72 carbureted tank so I had to either sump it or run a later model fuel injected tank. If all you want to do is add larger fuel lines there may be an easier way. On my tank I drilled out the original lines and simply bolted in AN style bulk head fitting with viton 0-rings. On the inside of the tank I ran a pickup made of aluminum lines that ran into the sump. I had the bottom of the tank cut open at the time and I riveted a bracket that held down the pickup. I'm not so sure the riveting was absolutely necessary. As far as sealing and treating the tank I had great success with the Eastwood kit. I prepped the tank from what others have done on this site, a soapy rinse, followed by an alchol rinse. Then using my truck exhaust to dry the tank out worked great. Following the Eastwood directions I used muriatic acid to take out the rust and other junk followed by an acetone rinse. Then you coat the raw metal surface with some sort of treatment, I forgot what it was now but it turned the shiny metal to like a cadium plated metal. Rinse the tank with alchohol and pour in the sealer. It looks like elmers blue and you slosh it around the whole tank turning every which way and upside down. I finished the tank, sumped and sealed in two weekends for under $100.

Did you try another ignitor? This is the test I came up with a while back when I had a new one and the old "bad" one to compare. I had a meter set up to measure resistance between the blue wire and the housing of the ignitor body (the body is normaly grounded when mounted in the car). With a little smoke alarm type 9 volt battery, I hooked the negative end to the ignitor body. Now watching the meter, hook the positive end of the 9v battery to where the yellow/white wire would normally go. A good ignitor will show a big change in resistance from high (disconnected) to low (connected), something like 2Kohms to 200ohms, but don't quote me on those exact values, this is from memory. A bad ignitor shows no change and may always have a high resistance.

yellow white will be at zero while at rest. It should be pulsed while cranking or running. At each pulse the coil circuit is grounded and you get an arc.

The output to transistor/ignitor is a pulsed wave that varies frequency on engine speed. It is very difficult to see without a digital oscope. With a meter you may measure some DC voltage but it is an unreliable reading. Here's a pic: http://forums.hybridz.org/showthread.php?t=102960&highlight=ignitor I don't have time to find it right now, but I did write up a way to check a while back that worked for me with a small tranistor 12v battery.

I'm not ready to race my z yet, but I'll probably go check it out.