I'm trying to help my son get a 94 Camaro with LT1 engine to start. Car was gifted to him cause the previous owner couldn't get it started. We have spark to the plugs, so the opt spark must be doing something, the check engine light comes on, so I assume the computer is alive, but other than that I have no idea what to check. No way I can change this to points and a carb? Just kidding. I thought some of you might have experience with these animals, so any help would be appreciated. Thanks
Actually... you could change it to points and Carb with a GMC performance parts manifold... but don't. Lol. Is the security light on? Does it turn over? Are the injecters pulsing? What code is the causing the CEL? Is the car a t56 6 speed or a 4L60? What's the cracking and setting fuel pressure?? Need a lot more information, but I am very knowledgable when it comes to these engines. A code reader (obd1) is almost mandatory and a set of noid lights, a multi-meter, and a fuel pressure gauge will help a lot with trouble shooting.
Definitely make sure the security system isn't tripped. If it is try cleaning the little microchip on the key. Otherwise check the fuel pressure on the schrader valve located at the back of the fuel rail near the firewall. What all has the previous owner tried doing with it?
Thanks for the input. I think the OBD reader is something we have to get. Maybe it is throwing a code. Right now we have fuel pressure, and spark, but it won't start. I'll let you know if we can get a code out of it. I'm going to remind him to check the security system also. Car is an auto, with less than 100k on it with a clean interior, so for free it ain't a bad deal and worth fixing
Some little things to try. Make sure the mass air fow sensor (large sender in the intake ducking) is on with the arrow pointing at the throttle body. If you try the starting fluid trick, that sensor must be connected so spray just up stream of the air filter. If it was a vats error (security) it wouldn't crank... if that's the problem I can tell you how to bypass. it for next to nothing. pm me if you need more help, butt ill keep my eyes on this thread.
As far as a noid night, a 194 bulb works perfectly. An OBDI code is esentially a paper clip. Its been a while, but you can jump out the A and B on the data link. What the OP needs is a no start flow chart for the car.
Where are you checking for spark? Where are you checking for fuel? Are you sure the fuel is good? Is the security light on when the key is switched to the "run" position? Are you sure there's enough battery voltage? Are you sure the grounds are solid? When you run the scanner on it check the temp to make sure it's not reading a negative number. If it is than the temp sensor is bad and trying to run it super rich to get it to warm up.
There are a few web sites that offer good tips on diagnosing the "opti" on the LT1s. I have a 94' Caprice LS LT1, also a 9C1. I had spark, I had fuel pressure. The opti was bad. One tip - don't buy just a "cap and rotor" as the tiny inverse-torx screws will probably be seized. Get the entire distributor. This is also a good time to change the wires and plugs. It's a pain on the Caprice; I haven't worked on a F-car but it isn't easier.
Found a step by step for you http://www.mainstreamtopics.com/forums/topic/78-lt1-no-start-diagnostic/
And a paper clip will allow you to jump terminals and read basic codes, but data logging with a scanner makes life easier. Intake air temp, as previously stated, is a big deal. Has a ton to do with fuel mixture.
opti is fixed. can't be adjusted. if it were me and your getting spark and fuel pressure and it doesn't crank super fast like no compression i would pull the opti and have a look. it will either be missing the Torx screws that hold the shaft Om the inside or the metal ribbon will be scratched to hell or the Rotor screws will be missing. if the water pump leaks a drop it will kill the opti to
oh ya. they say its impossible. but don't put it on wrong. I've seen 2 people force them on in the wrong hole and don't put the water pump back On till you try to start it. for the above reason.
if you find out it the optispark before buying one pm me, i'll sell you a new extra one that i have for a lot less than you can buy a new one for.. Dan C
Jumping the A & B pins on the data link will turn on the engine cooling fan but will not display codes. This is the worst thing about these stupid F-cars...I'm having intermittant start issues with my '94 Z28 6M convertible & am too stubborn to pay someone else to hook it up. I've heard that you can't just buy any scanner to read this thing either. But the "I've heard" phrase is of little value to anyone on this board... I bought the running gear out of a complete '94 Z at the scrapyard Thursday for $100 so for now I'll plug-n-play. Got to pull it out Tuesday morning before work which will be f.u.n. Can't go wrong for $100..heck, the peripherals are worth that.
I had a old otc explorer. It's not to hard to find a obd1 scanner cheap, where you have to spend money is when you have a 95 fbody.... obd2 data link with a obd1 computer.
