I recently completed an LT1 swap in my firebird. I was thrilled to here it crank and run yesterday. I cranked it today and it ran fine, I tried to crank it later on and nothing. The engine turns over fine, but pops back through the intake. It will not start. I checked all fuses, and they are fine. How do I check the opti? I have no clue what could be wrong, please help. The only thing I did between times was hook up a black wire at the firewall plug.

 

Unhook the plug? Does it work?

 

The car will not run with the plug disconnected. I disconected the wire last night and there was no difference. I think it might be ignition related since the last time it ran the tach bounced around and quit. This was the first time I let the car get to operating temp. Can I check the ignition module myself or do I have to remove it and have it tested? I am sorry to ask so many questions, but my car hasn't moved since November.

 

This may sound weird, but replace the plugs, or clean them. I have seen two seperate incidents like this and that's what solved the problem. Also make sure your opti is dry. Never spray water on it.

 

I checked every single electrical connection on the car and found my knock sensor and my passenger side o2 ensor were unplugged. I plugged them up and it fired right up, until it ran out of gas! It is loud as can be right now with an open Y-pipe. When I hooked it up my ses light started working. I appreciate everyones help and I hope it continues to go smoothly.

 

Glad you found the problem.

 

It seems that I fix one problem another arises. I went to do some work on my car today and it would not start. It turns over like the timing is way off. I don't know how to check timing on an LT1. What controls the advancing and retarding? I was almost tempted to set my car on fire today. I have tried everything and checked throughout this web site and it seems that no one has had a similiar problem. I don't think iwould be as bad if it weren't intermittent. Please help!

 

You problems are symptematic of a bad optispark.

 

Are you coming up with any codes? Sounds to me like it`s the opti-crap also.

 

agreed. unfortunately there really is no way to be 100% sure it is the opti until you replace it and the problem goes away. the best way to get a new one is to check camaroZ28.com and do a search, there are a number of guys on there that can get them alot cheaper than the dealer price. hope you find out what the problem is. stick with it till you do.

 

You can call Jason Cromer at 1-877-726-8295. Similar pricing to Gmpartsdirect but cheaper shipping.

 

I appreciate the info on the opti. I had my starter rebuilt and it fired right up. My car is possessed! I am going to wait on the opti until I fix the other problems. My tach doesn't work most of the time, my oil pressure sometimes pegs and my alternator sometimes charges 18 volts. I think my regulator may be bad . I have no clue on the others. Where do the guages ground? I am sorry to ask so many questions, but the closer my car gets to being driveable, the stranger my problems get. Thanks in advance!

 

I had my alternator tested and it was bad. I fixed a ground under the dash and my ses light started working. Could that ground be what is causing my guages to go goofy? I am thinking about running a wire from the firewall connector to my coil. Would this hurt anything?

 

I would ground it right to the engine block. Did you hook up the ground strap that bolts through the trans bellhousing?

 

I hooked the strap up, but it may not be grounding properly with aluminum heads. I hooked it up like my tune port was( to the head ). I tested more wires and found a loose ground under the dash on the passenger side. Now my ses light works and I can here emission solenoids clicking on the engine. I am going to move the ground strap and see if my oil pressure guage and tach start working.

 

Huh?!

 

On some cars there is a braided ground strap that grounds through one of the top trans bell housing bolts. My second gens had this. If it was not connected the wipers and other stuff would not operate properly.

 

Ya, I have a V6 Sport Coupe that im droppin an LT1 into, and it had the ground there as well...

With the LT1, I see a lot of people here have one, so whats all needed. Currently it has no engine, but it had a V6 with an Auto. I have heard that I need a POSI Rear, I most likely need a new tranny (how do I tell if its a 700R4?) And New engine mounts (duh) Whats the situation with the wiring and the computer and all that, what do i do with all the wiring i wanna leave alone like lights, guages ect... Do I need to splice or whatever anything? Can I just use a normal 350 Radiator, or the 4th gen Radiator? I doubt mine will work with it.

Sorry if my questions are unrelated, but I really love LT1s, and I found one cheap because my friend wrecked his 94 LT1. Am I the only one tryin to hook it to a 700R4? lol

Thanks!

 

The ground under the dash fixed all my problems except my tach. I had my alternator rebuilt and now my tach is working. I don't understand that. My tach shows that my car is idling at about 1700 RPM. I know this is too high. What could cause this. I would like to thank everyone for their help on this problem.

 

I have a crappy After market tach that sorta looks like a voltometer, lol... but it says that it idles at 2k. WTF... How can I adjust it?

 

I would ask one of the LT1 swappers how they resolved the tach issue.

An LS1 swap requires the use of a tach adapter to convert the signal from the PCM to one compatible with the tach. I would guess the same issue presents itself with the LT1 swap.