im in the process of starting this beast of mine...just wondering...if the computer doesnt see oil pressure will the engine still fire and run??i thought that the theft deterrent system just cut out fuel??i by passed the fuel relay and had the fuel pump running constantly while cranking..still no start..does the computer also cut out injectors or iginiton coils??really just tryin to get this this to run, its been a long time commin..thanks for any input!!!

 

The LS1 computer doesnt care about oil pressure. It doesnt need any input for it and it would start and run bone dry if you tried it.

As for the security. It shuts down the coils I believe. I cant ever remember whether it kills injectors or coils...but I believe it kills the coils. In most cases, the motor will start, run for a few seconds, and shut off if VATS is taking over. I fyou arent getting any fire at all, then you have something else going on I think.

Make sure all the pink wires are getting 12v while cranking. Thats a big thing with some swappers. You cant give the PCM and all the sensors 12v in run power...it has to be 12 volts when in run AND while cranking. Otherwise, while you are cranking nothing will be getting power. Like your lights and radio turn off while cranking.

J.

 

oh, i have plenty of fire, in fact i saw fire come out of the headers (using stock headers, no down pipe)..i also probably went the route that not to many people did on this site...I got an entire 4th gen pull out, engine, fuel tank with pump, fuel lines, exhaust, radiator with fans, all the wiring from the vehicle (including BCM)...so i decided that to go to GM and have them cut me a key (with the resistance of the new computer, but the cut of the old key)....i spliced the resistance wires from the steering coulmn into the BCM and hooked up everything correctly..i aslo have the fuel deterrent wire from connector c230 hooked up with the bcm...thinking that this set up would work, well it hasnt..i do have a vats by-pass module..tommorrow i'll check to see it the vats by-pass module works, if not i guess its back to the drawing board

 

What was your reasoning for using the BCM out of curiousity? Are you doing a full 4th gen dash swap and all? Just wanted to re-wire the car?

If you are getting fuel and fire out of the motor, it should start. Even with VATS you should get something. If you arent getting anything...something is missing. But thats just my experience. Ive also seen VATS do some weird crap that it wasnt supposed to...or wasnt the norm.

So ide try the bypass module and see what you get I guess. Otherwise, its time to go back over all your work and make sure everything is hooked up and has good connections. Check any suspect wires that you had to pull through the firewall or something for continuity.

After that, its down to sensors on the motor I guess. One of those little buggers could have gotten knocked around during your swap and decided to take a nap. But thats a whole nother animal to track down.

J.

 

Like Justin said, fuel and fire means its trying to start. For future reference, VATS kills fuel. Hook up some type of scanner or data logger to the ALDL and monitor whats going on while you're cranking. Something should be obvious

 

Ah...I knew I had it mixed up. I cant ever remember what it kills. When I was dealing with it I remembered haha. But that info has long since left my brain.

If you have most of the stuff hooked up, and things have power that need power...when they need power, its gotta be something simple. These motors are pretty hi tech compared to the old gen 1 sbc motors....but they are surprisingly simple and easy to make run. All they need is power to the right places, grounds, and some fuel.

J.

 

Good news..i decided to eliminate the BCM all together and use the VATS bypass module..first try it started and ran...finally success..but my curosity got the best of me and i decided to find out what the computer cuts out...I have a set of noid lights and a spark plug tester..with both installed, i turned the motor over and your can easily see that the fire stays constant, the problem is fuel..the computer kills the injector pulse..now time for some exhaust

 

So you're going to run open exhaust???

 

Hearing is overrated

 

I think he meant "Now time for some exhaust" or maybe not lol.

 

Oh.

 

yeah, i meant NOW TIME FOR EXHAUST...just not sure which route i wanna go, either hawks headers or just the stock manifolds and make my own exhaust from there..has anybody used the flowmaster Y pipe from summit or jegs??

 

Which stock manifolds do you have?

 

stock 98 camaro manifolds..also im tryin to get the spedometer to work along with the tach..ive looked for how to wire it up in the stickies, if someone could send me a link or just tell me..thanks..

 

Tach is in the C100. Connect it direct to the PCM tach wire. Most likely the value will be 1/2 actual engine speed. Your tuner can fix this by changing the setting. Stock, LSx engines output a 4cyl tach signal. The tuner would change the value to 3 for V8 tachs and 4 for V6 tachs. Firebirds usually end up needing the booster wire to get the gauge working. If your tach moves, you dont need the booster. If it doesnt, bump up the signal

Speedo is still simple, but not exactly direct. Connect the VSS output from the PCM to the C207 pin K. Next, find the buffer box behind the lower dash trim and unplug it. Connect pins C and F. Now you should have a direct connection from the PCM to the instrument cluster. You can run a new wire and bypass all of that pin finding, but to get to the inst cluster connector, youd have to disembowel the dash. Much easier to assign one pin and jumper two wires IMHO

 

so, i worked on the car this morining...got a new shifter cable from the junk yard for $5.00..installed it and finally after over a year pulled my car out of the garage..started the car and found a vacuum leak..fix it, and now the car idles great (no o2 sensor hooked up yet) also filled the tranny with fluid and drove the car around the apartment complex, waking up all the neighbours, hahahahaha..found a couple of problems tho, the alternator is not charging, i cant get my oil pressure guage to work, when i turn the key on with out starting, the oil pressure guage is pegged all the way past 60 psi..any suggestions..also i have to bleed my coolant system..is there a easy way to do it..but good news, car starts immediately, no hickups or misfires..

 

Pegged oil gauge usually means dead sender

For the alt, check the connection to the PCM. Its a strait shot

Easiest way to fill the coolant system in a LS1. Remove the T-stat and drill a 1/16" hole in it for air to pass through. Next, reinstall all hoses and leave the upper disconnected from the rad. Fill it to the top by pouring down this hose. It will take several fills to get everything. It should begin to overflow from the radiator when you're done. Next reconnect and take up to operating temp. Let it cool and top the radiator off. Thats all